Hubbry Logo
Strength trainingStrength trainingMain
Open search
Strength training
Community hub
Strength training
logo
8 pages, 0 posts
0 subscribers
Be the first to start a discussion here.
Be the first to start a discussion here.
Strength training
Strength training
Strength training
View on Wikipedia
from Wikipedia

A gym where various forms of strength training are being practiced. From left: overhead presses, battle ropes, planking, and kettlebell raises.

Strength training, also known as weight training or resistance training, is exercise designed to improve physical strength. It may involve lifting weights, bodyweight exercises (e.g., push-ups, pull-ups, and squats), isometrics (holding a position under tension, like planks), and plyometrics (explosive movements like jump squats and box jumps).[1]

Training works by progressively increasing the force output of the muscles and uses a variety of exercises and types of equipment. Strength training is primarily an anaerobic activity, although circuit training also is a form of aerobic exercise.

Strength training can increase muscle, tendon, and ligament strength as well as bone density, metabolism, and the lactate threshold; improve joint and cardiac function; and reduce the risk of injury in athletes and the elderly. For many sports and physical activities, strength training is central or is used as part of their training regimen.

Principles and training methods

[edit]

Strength training follows the fundamental principle that involves repeatedly overloading a muscle group. This is typically done by contracting the muscles against heavy resistance and then returning to the starting position. This process is repeated for several repetitions until the muscles reach the point of failure.[2] Strength training typically follows the principle of progressive overload, in which muscles are subjected to gradually increasing resistance over time to stimulate adaptation and growth.[3] They respond by growing larger and stronger.[4] Beginning strength-trainers are in the process of training the neurological aspects of strength, the ability of the brain to generate a rate of neuronal action potentials that will produce a muscular contraction that is close to the maximum of the muscle's potential.[5]

Proper form

[edit]
A dumbbell half-squat.[6]

Strength training also requires the use of proper or 'good form', performing the movements with the appropriate muscle group, and not transferring the weight to different body parts in order to move greater weight (called 'cheating'). An injury or an inability to reach training objectives might arise from poor form during a training set. If the desired muscle group is not challenged sufficiently, the threshold of overload is never reached and the muscle does not gain in strength. At a particularly advanced level, however, "cheating" can be used to break through strength plateaus and encourage neurological and muscular adaptation.[7]

Maintaining proper form is one of the many steps in order to perfectly perform a certain strength training technique. Correct form in weight training improves strength, muscle tone, and maintaining a healthy weight. Improper form can lead to strains and fractures.[8]

Stretching and warm-up

[edit]
Main article: Warming up

Weight trainers often spend time warming up before starting their workout, a practice strongly recommended by the National Strength and Conditioning Association (NSCA). A warm-up may include cardiovascular activity such as light stationary biking (a "pulse raiser"), flexibility and joint mobility exercises, static and/or dynamic stretching, "passive warm up" such as applying heat pads or taking a hot shower, and workout-specific warm-up,[9] such as rehearsal of the intended exercise with no weights or light weights. The intended purpose of warming up is to enhance exercise effectiveness and reduce the risk of injury.[10]

Evidence is limited regarding whether warming up reduces injuries during strength training.[10] As of 2015, no articles existed on the effects of warm-up for upper body injury prevention.[11] For the lower limbs, several programs significantly reduce injuries in sports and military training, but no universal injury prevention program has emerged, and it is unclear if warm-ups designed for these areas will also be applicable to strength training.[12] Static stretching can increase the risk of injury due to its analgesic effect and cellular damage caused by it.[13]

The effects of warming up on exercise effectiveness are clearer. For 1RM (One-repetition maximum) trials, an exercise rehearsal has significant benefits. For submaximal strength training (3 sets of 80% of 1RM to failure), exercise rehearsal does not provide any benefits regarding fatigue or total repetitions for exercises such as bench press, squats, and arm curl, compared to no warm-up.[10] Dynamic warm-ups (performed with greater than 20% of maximal effort) enhance strength and power in upper-body exercises.[11] When properly warmed up the lifter will have more strength and stamina since the blood has begun to flow to the muscle groups.[14] Pulse raisers do not have any effect on either 1RM or submaximal training.[10] Static stretching induces strength loss, and should therefore probably not be performed before strength training. Resistance training functions as an active form of flexibility training, with similar increases in range of motion when compared to performing a static stretching protocol. Static stretching, performed either before or after exercise, also does not reduce muscle soreness in healthy adults.[10]

Breathing

[edit]

Like numerous forms of exercise, weight training has the potential to cause the breathing pattern to deepen. This helps to meet increased oxygen requirements. One approach to breathing during weight training consists of avoiding holding one's breath and breathing shallowly. The benefits of this include protecting against a lack of oxygen, passing out, and increased blood pressure. The general procedure of this method is to inhale when lowering the weight (the eccentric portion) and exhale when lifting the weight (the concentric portion). However, the reverse, inhaling when lifting and exhaling when lowering, may also be recommended. There is little difference between the two techniques in terms of their influence on heart rate and blood pressure.[15]

On the other hand, for people working with extremely heavy loads (such as powerlifters), breathing à la the Valsalva maneuver is often used. This involves deeply inhaling and then bracing down with the abdominal and lower back muscles as the air is held in during the entire rep. Air is then expelled once the rep is done, or after a number of reps is done. The Valsalva maneuver leads to an increase in intrathoracic and intra-abdominal pressure. This enhances the structural integrity of the torso—protecting against excessive spinal flexion or extension and providing a secure base to lift heavy weights effectively and securely.[16] However, as the Valsalva maneuver increases blood pressure, lowers heart rate, and restricts breathing, it can be a dangerous method for those with hypertension or for those who faint easily.

Training volume

[edit]

Training volume is commonly defined as sets × reps × load. That is, an individual moves a certain load for some number of repetitions, rests, and repeats this for some number of sets, and the volume is the product of these numbers. For non-weightlifting exercises, the load may be replaced with intensity, the amount of work required to achieve the activity. Training volume is one of the most critical variables in the effectiveness of strength training. There is a positive relationship between volume and hypertrophy.[17][18]

The load or intensity is often normalized as the percentage of an individual's one-repetition maximum (1RM). Due to muscle failure, the intensity limits the maximum number of repetitions that can be carried out in one set, and is correlated with the repetition ranges chosen. Depending on the goal, different loads and repetition amounts may be appropriate:[19]

  • Strength development (1RM performance): Gains may be achieved with a variety of loads. However, training efficiency is maximized by using heavy loads (80% to 100% of 1RM). The number of repetitions is secondary and may be 1 to 5 repetitions per set.[19]
  • Muscle growth (hypertrophy): Hypertrophy can be maximized by taking sets to failure or close to failure. Any load 30% of 1RM or greater may be used. The NCSA recommends "medium" loads of 8 to 12 repetitions per set with 60% to 80% of 1RM.[19]
  • Endurance: Endurance may be trained by performing many repetitions, such as 15 or more per set. The NCSA recommends "light" loads below 60% of 1RM, but some studies have found conflicting results suggesting that "moderate" 15-20RM loads may work better when performed to failure.[19]

Training to muscle failure is not necessary for increasing muscle strength and muscle mass, but it also is not harmful.[20]

Movement tempo

[edit]

The speed or pace at which each repetition is performed is also an important factor in strength and muscle gain. The emerging format for expressing this is as a 4-number tempo code such as 3/1/4/2, meaning an eccentric phase lasting 3 seconds, a pause of 1 second, a concentric phase of 4 seconds, and another pause of 2 seconds. The letter X in a tempo code represents a voluntary explosive action whereby the actual velocity and duration is not controlled and may be involuntarily extended as fatigue manifests, while the letter V implies volitional freedom "at your own pace". A phase's tempo may also be measured as the average movement velocity. Less precise but commonly used characterizations of tempo include the total time for the repetition or a qualitative characterization such as fast, moderate, or slow. The ACSM recommends a moderate or slower tempo of movement for novice- and intermediate-trained individuals, but a combination of slow, moderate, and fast tempos for advanced training.[21]

Intentionally slowing down the movement tempo of each repetition can increase muscle activation for a given number of repetitions. However, the maximum number of repetitions and the maximum possible load for a given number of repetitions decreases as the tempo is slowed. Some trainers calculate training volume using the time under tension (TUT), namely the time of each rep times the number of reps, rather than simply the number of reps.[21] However, hypertrophy is similar for a fixed number of repetitions and each repetition's duration varying from 0.5 s - 8 s. There is however a marked decrease in hypertrophy for "very slow" durations greater than 10 s.[22] There are similar hypertrophic effects for 50-60% 1RM loads with a slower 3/0/3/0 tempo and 80-90% 1RM loads with a faster 1/1/1/0 tempo. It may be beneficial for both hypertrophy and strength to use fast, short concentric phases and slower, longer eccentric phases. Research has not yet isolated the effects of concentric and eccentric durations, or tested a wide variety of exercises and populations.[21]

Weekly frequency

[edit]

In general, more weekly training sessions lead to higher increases in physical strength. However, when training volume was equalized, training frequency had no influence on muscular strength. In addition, greater frequency had no significant effect on single-joint exercises. There may be a fatigue recovery effect in which spreading the same amount of training over multiple days boosts strength gains, but this has to be confirmed by future studies.[23]

For muscle growth, a training frequency of two sessions per week had greater effects than once per week. Whether training a muscle group three times per week is superior to a twice-per-week protocol remains to be determined.[24]

Rest period

[edit]

The rest period is defined as the time dedicated to recovery between sets and exercises. Exercise causes metabolic stress, such as the buildup of lactic acid and the depletion of adenosine triphosphate and phosphocreatine.[25] Resting 3–5 minutes between sets allows for significantly greater repetitions in the next set versus resting 1–2 minutes.[26]

For untrained individuals (no previous resistance training experience), the effect of resting on muscular strength development is small and other factors such as volitional fatigue and discomfort, cardiac stress, and the time available for training may be more important. Moderate rest intervals (60-160s) are better than short (20-40 s), but long rest intervals (3–4 minutes) have no significant difference from moderate.[25]

For trained individuals, rest of 3–5 minutes[27] is sufficient to maximize strength gain, compared to shorter intervals 20s-60s and longer intervals of 5 minutes. Intervals of greater than 5 minutes have not been studied.[25] Starting at 2 minutes and progressively decreasing the rest interval over the course of a few weeks to 30s can produce similar strength gains to a constant 2 minutes.[28][25]

Regarding older individuals, a 1-minute rest is sufficient in females.[25]

Order

[edit]

The largest increases in strength happen for the exercises in the beginning of a session.[29]

Supersets are defined as a pair of different exercise sets performed without rest, followed by a normal rest period. Common superset configurations are two exercises for the same muscle group, agonist-antagonist muscles, or alternating upper and lower body muscle groups.[30] Exercises for the same muscle group (flat bench press followed by the incline bench press) result in a significantly lower training volume than a traditional exercise format with rests.[31] However, agonist–antagonist supersets result in a significantly higher training volume when compared to a traditional exercise format.[32] Similarly, holding training volume constant but performing upper–lower body supersets and tri-sets reduce elapsed time but increased perceived exertion rate.[33] These results suggest that specific exercise orders may allow more intense, more time-efficient workouts with results similar to longer workouts.[30]

Periodization

[edit]
See also: Sports periodization

Periodization refers to the organization of training into sequential phases and cyclical periods, and the change in training over time. The simplest strength training periodization involves keeping a fixed schedule of sets and reps (e.g. 2 sets of 12 reps of bicep curls every 2 days), and steadily increasing the intensity on a weekly basis. This is conceptually a parallel model, as several exercises are done each day and thus multiple muscles are developed simultaneously. It is also sometimes called linear periodization, but this designation is considered a misnomer.[34]

Sequential or block periodization concentrates training into periods ("blocks"). For example, for athletes, performance can be optimized for specific events based on the competition schedule. An annual training plan may be divided hierarchically into several levels, from training phases down to individual sessions. Traditional periodization can be viewed as repeating one weekly block over and over. Block periodization has the advantage of focusing on specific motor abilities and muscle groups.[34] Because only a few abilities are worked on at a time, the effects of fatigue are minimized. With careful goal selection and ordering, there may be synergistic effects. A traditional block consists of high-volume, low-intensity exercises, transitioning to low-volume, high-intensity exercises. However, to maximize progress to specific goals, individual programs may require different manipulations, such as decreasing the intensity and increasing volume.[35]

Undulating periodization is an extension of block periodization to frequent changes in volume and intensity, usually daily or weekly. Because of the rapid changes, it is theorized that there will be more stress on the neuromuscular system and better training effects. Undulating periodization yields better strength improvements on 1RM than non-periodized training.[34] For hypertrophy, it appears that daily undulating periodization has similar effect to more traditional models.[36]

Training splits

[edit]
Further information: Split weight training

A training split refers to how the trainee divides and schedules their training volume, or in other words which muscles are trained on a given day over a period of time (usually a week). Popular training splits include full body, upper/lower, push/pull/legs, and the "bro" split. Some training programs may alternate splits weekly.[37][better source needed]

Exercise selection

[edit]
Further information: List of weight training exercises

Exercise selection depends on the goals of the strength training program. If a specific sport or activity is targeted, the focus will be on specific muscle groups used in that sport. Various exercises may target improvements in strength, speed, agility, or endurance.[38] For other populations such as older individuals, there is little information to guide exercise selection, but exercises can be selected on the basis of specific functional capabilities as well as the safety and efficiency of the exercises.[39]

For strength and power training in able-bodied individuals, the NCSA recommends emphasizing integrated or compound movements (multi-joint exercises), such as with free weights, over exercises isolating a muscle (single-joint exercises), such as with machines.[40] This is due to the fact that only the compound movements improve gross motor coordination and proprioceptive stabilizing mechanisms.[38] However, single-joint exercises can result in greater muscle growth in the targeted muscles,[41] and are more suitable for injury prevention and rehabilitation.[40] Low variation in exercise selection or targeted muscle groups, combined with a high volume of training, is likely to lead to overtraining and training maladaptation.[42] Many exercises such as the squat have several variations. Some studies have analyzed the differing muscle activation patterns, which can aid in exercise selection.[43]

Equipment

[edit]

Commonly used equipment for resistance training include free weights—including dumbbells, barbells, and kettlebells—weight machines, and resistance bands.[44]

Resistance can also be generated by inertia in flywheel training instead of by gravity from weights, facilitating variable resistance throughout the range of motion and eccentric overload.[45][46]

Some bodyweight exercises do not require any equipment, and others may be performed with equipment such as suspension trainers or pull-up bars.[47]

Types of strength training exercises

[edit]

Aerobic exercise versus anaerobic exercise

[edit]
See also: Anaerobic exercise

Strength training exercise is primarily anaerobic.[48] Even while training at a lower intensity (training loads of ≈20-RM), anaerobic glycolysis is still the major source of power, although aerobic metabolism makes a small contribution.[49] Weight training is commonly perceived as anaerobic exercise, because one of the more common goals is to increase strength by lifting heavy weights. Other goals such as rehabilitation, weight loss, body shaping, and bodybuilding often use lower weights, adding aerobic character to the exercise.

Except in the extremes, a muscle will fire fibres of both the aerobic or anaerobic types on any given exercise, in varying ratio depending on the load on the intensity of the contraction.[48] This is known as the energy system continuum. At higher loads, the muscle will recruit all muscle fibres possible, both anaerobic ("fast-twitch") and aerobic ("slow-twitch"), to generate the most force. However, at maximum load, the anaerobic processes contract so forcefully that the aerobic fibers are completely shut out, and all work is done by the anaerobic processes. Because the anaerobic muscle fibre uses its fuel faster than the blood and intracellular restorative cycles can resupply it, the maximum number of repetitions is limited.[50] In the aerobic regime, the blood and intracellular processes can maintain a supply of fuel and oxygen, and continual repetition of the motion will not cause the muscle to fail.

Circuit weight training is a form of exercise that uses a number of weight training exercise sets separated by short intervals. The cardiovascular effort to recover from each set serves a function similar to an aerobic exercise, but this is not the same as saying that a weight training set is itself an aerobic process.

Strength training is typically associated with the production of lactate, which is a limiting factor of exercise performance. Regular endurance exercise leads to adaptations in skeletal muscle which can prevent lactate levels from rising during strength training. This is mediated via activation of PGC-1alpha which alter the LDH (lactate dehydrogenase) isoenzyme complex composition and decreases the activity of the lactate generating enzyme LDHA, while increasing the activity of the lactate metabolizing enzyme LDHB.[51]

Nutrition and supplementation

[edit]
Main article: Sports nutrition

Supplementation of protein in the diet of healthy adults increases the size and strength of muscles during prolonged resistance exercise training (RET); protein intakes of greater than 1.62 grams per kilogram of body weight a day did not additionally increase fat–free mass (FFM), muscle size, or strength, in a non-energy restricted context.[52] Older lifters may experience less of an effect from protein supplementation on resistance training.[52]

It is not known how much carbohydrate is necessary to maximize muscle hypertrophy. Strength adaptations may not be hindered by a low-carbohydrate diet.[53]

A light, balanced meal prior to the workout (usually one to two hours beforehand) ensures that adequate energy and amino acids are available for the intense bout of exercise.[54] The type of nutrients consumed affects the response of the body, and nutrient timing whereby protein and carbohydrates are consumed prior to and after workout has a beneficial impact on muscle growth.[55] Water is consumed throughout the course of the workout to prevent poor performance due to dehydration. A protein shake is often consumed immediately[56] following the workout. However, the anabolic window is not particularly narrow and protein can also be consumed before or hours after the exercise with similar effects.[57] Glucose (or another simple sugar) is often consumed as well since this quickly replenishes any glycogen lost during the exercise period. If consuming recovery drink after a workout, to maximize muscle protein anabolism, it is suggested that the recovery drink contain glucose (dextrose), protein (usually whey) hydrolysate containing mainly dipeptides and tripeptides, and leucine.[58]

Some weight trainers also take ergogenic aids such as creatine[59] or anabolic steroids to aid muscle growth.[60] In a meta-analysis study that investigated the effects of creatine supplementation on repeated sprint ability, it was discovered that creatine increased body mass and mean power output.[61] The creatine-induced increase in body mass was a result of fluid retention.[61] The increase in mean power output was attributed to creatine's ability to counteract the lack of intramuscular phosphocreatine.[61] Creatine does not have an effect on fatigue or maximum power output.[61]

Hydration

[edit]

As with other sports, weight trainers should avoid dehydration throughout the workout by drinking sufficient water. This is particularly true in hot environments, or for those older than 65.[62][63][64][65][66]

Some athletic trainers advise athletes to drink about 7 imperial fluid ounces (200 mL) every 15 minutes while exercising, and about 80 imperial fluid ounces (2.3 L) throughout the day.[67]: 75 

However, a much more accurate determination of how much fluid is necessary can be made by performing appropriate weight measurements before and after a typical exercise session, to determine how much fluid is lost during the workout. The greatest source of fluid loss during exercise is through perspiration, but as long as fluid intake is roughly equivalent to the rate of perspiration, hydration levels will be maintained.[64]

Under most circumstances, sports drinks do not offer a physiological benefit over water during weight training.[67]: 76  However, under certain conditions—such as prolonged training sessions lasting over an hour, or when exercising in extremely hot and humid environments—sports drinks containing electrolytes and carbohydrates may help replenish lost salts and provide an energy boost. Ultimately, the ideal hydration approach depends on the individual's training intensity, duration, and personal needs.[68]

Insufficient hydration may cause lethargy, soreness or muscle cramps.[67]: 153  The urine of well-hydrated persons should be nearly colorless, while an intense yellow color is normally a sign of insufficient hydration.[67]: 153 

Effects

[edit]

The effects of strength training include greater muscular strength, improved muscle tone and appearance, increased endurance, cardiovascular health, and enhanced bone density.[69] These benefits contribute not only to athletic performance but also to long-term health and independence, especially as individuals age. Regular resistance training supports metabolic function, helps regulate body weight, and can improve mental well-being through the release of endorphins.

Bones, joints, frailty, posture and in people at risk

[edit]

Strength training also provides functional benefits. Stronger muscles improve posture,[vague] provide better support for joints,[vague] and reduce the risk of injury from everyday activities.[70][71]

Progressive resistance training may improve function, quality of life and reduce pain in people at risk of fracture, with rare adverse effects.[72] Weight-bearing exercise also helps to prevent osteoporosis and to improve bone strength in those with osteoporosis.[73] For many people in rehabilitation or with an acquired disability, such as following stroke or orthopaedic surgery, strength training for weak muscles is a key factor to optimise recovery.[74] Consistent exercise can actually strengthen bones and prevent them from getting frail with age.[75]

Mortality, longevity, muscle and body composition

[edit]

Engaging in strength training has been linked to a 10–17% reduction in the risk of death from all causes, including cardiovascular disease, cancer, diabetes, and lung cancer.[76] Two of its primary effects—muscle growth (hypertrophy) and increased muscular strength—are both associated with improved longevity and lower mortality rates.[77]

Strength training also triggers hormonal changes that may contribute to positive health outcomes.[78] It can help lower both systolic and diastolic blood pressure,[79][80] and positively influence body composition by decreasing overall body fat, visceral fat, and fat mass.[81] These changes are particularly beneficial since excess body fat and its distribution are closely linked to insulin resistance and the development of chronic diseases.[82]

Neurobiological effects

[edit]

Strength training also leads to various beneficial neurobiological effects – likely including functional brain changes, lower white matter atrophy,[83] neuroplasticity[84] (including some degree of BDNF expression),[85] and white matter-related structural and functional changes in neuroanatomy.[86] Although resistance training has been less studied for its effect on depression than aerobic exercise, it has shown benefits compared to no intervention.[87]

Lipid and inflammatory outcomes

[edit]

Moreover, it also promotes decreases in total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL), and C-reactive protein (CRP) as well as increases in high-density lipoprotein (HDL) and adiponectin concentrations.[88]

Sports performance

[edit]

Stronger muscles improve performance in a variety of sports. Sport-specific training routines are used by many competitors. These often specify that the speed of muscle contraction during weight training should be the same as that of the particular sport.[89] Strength training can substantially prevent sports injuries,[90] increase jump height and improve change of direction.

Neuromuscular adaptations

[edit]

Strength training is not only associated with an increase in muscle mass, but also an improvement in the nervous system's ability to recruit muscle fibers and activate them at a faster rate.[91] Neural adaptations can occur in the motor cortex, the spinal cord, and/or neuromuscular junctions. The initial significant improvements in strength amongst new lifters are a result of increased neural drive, motor unit synchronization, motor unit excitability, rate of force development, muscle fiber conduction velocity, and motor unit discharge rate.[91] Together, these improvements provide an increase in strength separate from muscle hypertrophy.[92] Typically, the main barbell lifts – squat, bench, and deadlift – are performed with a full range of motion, which provides the greatest neuromuscular improvements compared to one-third or two-thirds range of motion.[93] However, there are reasons to perform these lifts with less range of motion, particularly in the powerlifting community. By limiting range of motion, lifters can target a specific joint angle in order to improve their sticking points by training their neural drive. Neuromuscular adaptations are critical for the development of strength, but are especially important in the aging adult population, as the decline in neuromuscular function is roughly three times as great (≈3% per year) as the loss of muscle mass (≈1% per year).[94] By staying active and following a resistance training program, older adults can maintain their movement, stability, balance, and independence.

History

[edit]
See also: History of physical training and fitness
Arthur Saxon performing a Two Hands Anyhow with an early kettlebell and plate-loaded barbell

The genealogy of lifting can be traced back to the beginning of recorded history[95] where humanity's fascination with physical abilities can be found among numerous ancient writings. In many prehistoric tribes, they would have a big rock they would try to lift, and the first one to lift it would inscribe their name into the stone. Such rocks have been found in Greek and Scottish castles.[96] Progressive resistance training dates back at least to Ancient Greece, when legend has it that wrestler Milo of Croton trained by carrying a newborn calf on his back every day until it was fully grown. Another Greek, the physician Galen, described strength training exercises using the halteres (an early form of dumbbell) in the 2nd century.

Ancient Greek sculptures also depict lifting feats. The weights were generally stones, but later gave way to dumbbells. The dumbbell was joined by the barbell in the later half of the 19th century. Early barbells had hollow globes that could be filled with sand or lead shot, but by the end of the century these were replaced by the plate-loading barbell commonly used today.[97]

Weightlifting was first introduced in the Olympics in the 1896 Athens Olympic Games as a part of track and field, and was officially recognized as its own event in 1914.[98]

The 1960s saw the gradual introduction of exercise machines into the still-rare strength training gyms of the time. Weight training became increasingly popular in the 1970s, following the release of the bodybuilding movie Pumping Iron, and the subsequent popularity of Arnold Schwarzenegger. Since the late 1990s, increasing numbers of women have taken up weight training; currently, nearly one in five U.S. women engage in weight training on a regular basis.[99]

Subpopulations

[edit]

Sex differences

[edit]

Men and women have similar reactions to resistance training with comparable effect sizes for hypertrophy and lower body strength, although some studies have found that women experience a greater relative increase in upper-body strength. Because of their greater starting strength and muscle mass, absolute gains are higher in men.[100] In older adults, women experienced a larger increase in lower-body strength.[101]

[edit]

Orthopaedic specialists used to recommend that children avoid weight training because the growth plates on their bones might be at risk. The very rare reports of growth plate fractures in children who trained with weights occurred as a result of inadequate supervision, improper form or excess weight, and there have been no reports of injuries to growth plates in youth training programs that followed established guidelines.[102][103] The position of the National Strength and Conditioning Association is that strength training is safe for children if properly designed and supervised.[104] The effects of training on youth have been shown to depend on the methods of training being implemented. Studies from the Journal of Strength and Conditioning Research concluded that both Resistance Training and Plyometric training led to significant improvements in peak torque, peak rate of torque development, and jump performance, with Plyometric showing a greater improvement in jump performance compared to Resistance training.[105] Another study saw results that suggest that both high-load, low-repetition and moderate-load, high-repetition resistance training can be prescribed to improve muscular fitness in untrained adolescents, as well as the jump height had also increased.[106][107] These finding can be used in the future to develop training programs for youth athletes.[105] The big takeaway from these studies is that not only in training important for the development of strength for young athletes, but also it shows that when developing a program, having both plyometrics exercise and resistance training will result in better adaptations in the short and long term.[105] This can be attributed to the effect of neuromuscular development and the principle that it comes faster for adolescents than muscular hypertrophy. Understanding this is crucial for those in charge of creating programs for the youth to avoid injury and/or overtraining.[106][107] Since adolescents are still in growing and are not done with developing not only musculature but also bone and joint structures. Younger children are at greater risk of injury than adults if they drop a weight on themselves or perform an exercise incorrectly; further, they may lack understanding of, or ignore the safety precautions around weight training equipment. As a result, supervision of minors is considered vital to ensuring the safety of any youth engaging in strength training.[102][103]

Older adults

[edit]

Aging is associated with sarcopenia, a decrease in muscle mass and strength.[108][109][110] Resistance training can mitigate this effect,[108][110][111] and even the oldest old (those above age 85) can increase their muscle mass with a resistance training program, although to a lesser degree than younger individuals.[108] With more strength older adults have better health, better quality of life, better physical function[110] and fewer falls.[110] Resistance training can improve physical functioning in older people, including the performance of activities of daily living.[110][108] Resistance training programs are safe for older adults, can be adapted for mobility and disability limitations, and may be used in assisted living settings.[108] Resistance training at lower intensities such as 45% of 1RM can still result in increased muscular strength.[112]

See also

[edit]

References

[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

Strength training

View on Grokipedia
from Grokipedia
Strength training, also known as resistance training, is a specialized method of physical exercise designed to improve muscular fitness by requiring muscles to exert force against external resistance, such as weights, bands, or body weight, thereby enhancing the ability to generate or resist force. This form of training induces muscular contractions that promote adaptations in strength, (increase in muscle size), and anaerobic endurance, distinguishing it from aerobic exercises like running or . Common methods include free weights (e.g., barbells and dumbbells), weight machines, resistance bands, medicine balls, and bodyweight exercises such as push-ups or squats, allowing for to continually challenge the muscles. Engaging in strength training yields significant health benefits across all age groups. Large cohort studies and meta-analyses have associated strength training with a 21% lower risk of all-cause mortality. It is regarded as one of the most beneficial forms of exercise for promoting longevity and quality of life. Strength training can help preserve and enhance muscle mass at any age and, by stressing bones, increase bone density to reduce the risk of osteoporosis. Engaging in strength training yields significant health benefits across all age groups, including increased muscle mass and strength, which help counteract age-related sarcopenia (muscle loss) and improve overall physical function. Lower grip strength, a key measure of muscle strength, is a robust predictor of higher all-cause mortality risk, with meta-analyses showing approximately a 16% increased risk per 5 kg decrement. It also strengthens bones, reducing the risk of and fractures, while enhancing metabolic health by improving insulin sensitivity and aiding in . For older adults, regular strength training lowers the incidence of falls, alleviates symptoms by reducing pain and stiffness, and supports by preserving daily activity capabilities. Additionally, it contributes to cardiovascular health by lowering risks of heart disease and , and may even enhance mental well-being through improved mood and cognitive function. Health organizations recommend that adults perform muscle-strengthening activities targeting all major muscle groups (legs, hips, back, abdomen, chest, shoulders, and arms) at least two days per week, using moderate or high intensity to achieve optimal results. Programs should emphasize proper form to prevent injury, starting with lighter loads and progressing gradually, and can be adapted for various fitness levels, from beginners using body weight to athletes employing advanced techniques like Olympic lifts. Despite its accessibility—requiring minimal equipment in many cases—consultation with a healthcare provider is advised for individuals with pre-existing conditions to ensure safe implementation.

Fundamentals

Definition and Types

Strength training, also known as resistance training, is a form of designed to improve muscular fitness by exercising muscles or muscle groups against external resistance, thereby enhancing strength, , and size. This process typically involves performing exercises using body weight, free weights such as barbells and dumbbells, weight machines, or resistance bands, with the goal of progressively challenging the muscles to adapt. The resistance can be applied in various forms to target specific physiological responses, distinguishing strength training from other exercise modalities like aerobic activities. Strength training exercises are categorized based on the type of involved. Isometric exercises feature static muscle contractions where the muscle length remains constant without joint movement, such as holding a plank position to engage . Isotonic exercises involve dynamic contractions where muscle tension stays relatively constant while the muscle length changes, including concentric (shortening) and eccentric (lengthening) phases, as seen in squats where the contract to lift and lower the body. Isokinetic exercises maintain a constant speed of movement throughout the , typically requiring specialized machines like dynamometers to provide variable resistance, allowing for controlled acceleration and deceleration. Specialized variants of strength training focus on particular goals and competitive formats. emphasizes maximal strength in three compound lifts: the squat, , and , where athletes compete to achieve the highest total weight lifted across three attempts per lift. prioritizes and aesthetic symmetry through targeted resistance exercises that isolate muscle groups, often involving higher repetitions and varied angles to promote balanced development. , or simply , centers on explosive power through two Olympic lifts: the snatch, where the is lifted from the ground to overhead in one motion, and the clean and jerk, involving a pull to the shoulders followed by an . integrates multi-joint, multi-planar movements that mimic real-life activities to improve overall movement quality, coordination, and performance in daily tasks or sports, such as swings or throws. Key concepts in strength training include distinctions among maximal strength, , and , which guide exercise selection and loading. Maximal strength refers to the highest force a muscle can produce in a single effort, trained with heavy loads (typically 85-100% of ) and low repetitions, exemplified by deadlifts to build absolute lifting capacity. focuses on increasing muscle size through moderate loads (60-80% of ) and higher volume, promoting sarcoplasmic and myofibrillar growth via exercises like bicep curls. combines strength and speed, using lighter to moderate loads (30-60% of ) at high velocities to enhance rate of force development, as in Olympic lifts like the power clean.

Basic Principles

Strength training is grounded in several foundational principles that guide effective program design and ensure adaptations occur in response to exercise stimuli. The principle of is central, involving the gradual increase in stress on the musculoskeletal system—typically through higher loads, repetitions, or volume—to drive continued physiological adaptations and prevent plateaus in strength gains. This approach relies on systematically challenging the body beyond its current capacity, such as by incrementing weight lifted as a of over training sessions or cycles. Complementing progressive overload are the principles of specificity, individuality, and reversibility. Specificity dictates that training adaptations are tailored to the demands imposed, meaning exercises should mirror the movements, muscle groups, and energy systems relevant to an individual's goals, such as emphasizing lifts for athletic power. Individuality recognizes that responses to the same training stimulus vary based on factors like , training history, and baseline fitness, necessitating personalized programs to optimize outcomes and minimize injury risk. Reversibility highlights that strength gains are not permanent; without ongoing stimulus, muscular adaptations diminish over time, with detraining leading to losses in force production within weeks to months. The specific adaptations to imposed demands (SAID) principle encapsulates these ideas, positing that the body responds precisely to the type, intensity, and duration of stress applied during , resulting in targeted enhancements like increased neural efficiency for heavy lifts or improved power output for actions. Integral to this process is recovery, which allows for the repair of exercise-induced damage and the realization of adaptations; inadequate rest between sessions can impair neuromuscular function and hinder strength progress, while optimal recovery periods—often 24-72 hours depending on volume and exercise type—facilitate supercompensation and long-term gains. At the biomechanical level, the force-velocity relationship underpins these principles, describing an inverse curve where maximal force production decreases as contraction velocity increases, due to reduced time for actin-myosin cross-bridge formation during faster movements. In strength training, this relationship informs exercise selection: low-velocity, high-force actions (e.g., heavy squats) build maximal strength, while high-velocity efforts enhance power, with training shifting the curve to improve performance across the spectrum.

Training Methods

Exercise Selection and Equipment

Strength training exercises are broadly categorized into and isolation movements, which differ based on the number of joints and muscle groups involved. Compound exercises, also known as multi-joint exercises, engage multiple muscle groups simultaneously across several joints, promoting overall strength development and functional movement patterns. Examples include the , which targets the chest, shoulders, and , and the squat, which works the , hamstrings, glutes, and core. In contrast, isolation exercises focus on a single joint and primary muscle group, allowing for targeted development and refinement of specific areas. The , for instance, primarily isolates the brachii. This distinction is fundamental, as movements are often prioritized for efficiency in building foundational strength, while isolation exercises complement them for addressing imbalances or aesthetic goals. Equipment selection in strength training varies widely, encompassing free weights, machines, bodyweight exercises, and resistance bands, each offering unique advantages for different training levels and objectives. Free weights, such as barbells and dumbbells, require stabilization from accessory muscles, enhancing neuromuscular coordination and mimicking real-world movements, which can lead to greater overall strength gains. Machines provide guided paths of motion, making them ideal for beginners by minimizing the need for balance and reducing risk through controlled resistance. Bodyweight exercises, such as push-ups (targeting chest and arms), squats or front lunges (lower body), crunches (abdominals), hip lifts (glutes), and planks (core), rely on gravitational resistance and are highly accessible without any equipment. These are particularly recommended for beginners to start training at home, as they foster body control, endurance, and mastery of proper form. Resistance bands offer variable tension that increases through the , providing a portable and joint-friendly option suitable for rehabilitation or . indicates no significant differences in or maximal strength between free weights and machines when programs are equated for volume, though free weights may better improve stabilizer muscle activation. When selecting exercises and equipment, criteria such as muscular balance, progression, and individual goals guide the process to ensure safe and effective training. A balanced approach often incorporates a push-pull-legs framework, where push movements (e.g., presses) target anterior muscles, pull movements (e.g., rows) emphasize s, and exercises address lower body , preventing imbalances that could lead to . For beginners, it is recommended to start with bodyweight exercises at home or machine-based exercises in the gym to learn proper form safely and build confidence before progressing to free weights or more advanced compound variations to further challenge stabilizers and coordination. Beginners are commonly advised to perform full-body routines 2-3 times per week on non-consecutive days, with 2-3 sets of 15-20 repetitions per exercise while prioritizing correct technique, and to ensure 48-72 hours of rest between sessions for adequate recovery. In gym settings, machine-centered full-body workouts using exercises such as chest press, leg press, and lat pulldown are safe and effective options for novices. Gradually increase the load or difficulty as strength and proficiency improve. Equipment choices should align with goals: free weights and bodyweight for functional strength applicable to sports or daily activities, while machines and bands support aesthetic by allowing isolated focus. Common exercises include squat variations (e.g., back squat for lower body power), deadlifts (for strength), overhead and bench presses (for upper body pushing), and rows (for pulling balance). Integrating these based on whether the emphasis is functional performance or targeted muscle development optimizes outcomes without overcomplicating routines.

Programming Variables

Programming variables in strength training refer to the adjustable components of a workout program that influence adaptations such as , strength gains, and endurance. These variables include , , , rest periods, exercise order, and breathing techniques, each tailored to specific goals while ensuring and recovery. Optimizing these elements allows individuals to balance intensity and recovery, minimizing injury risk and maximizing physiological responses. Volume, defined as the total work performed in a session (sets × repetitions × load), is a primary driver of outcomes. For , guidelines recommend moderate loads at 60-80% of (1RM) with 3-5 sets of 6-12 repetitions per exercise, as this range promotes metabolic stress and mechanical tension conducive to muscle growth. Beginners, particularly those starting with bodyweight or machine-based exercises, are often recommended to use a higher repetition range of 15-20 repetitions per set for 2-3 sets to prioritize proper form and technique mastery before progressing to lower rep ranges for hypertrophy or strength. In contrast, strength-focused volume emphasizes heavier loads (above 85% 1RM) with fewer repetitions (1-6 per set) across 3-6 sets to enhance neural drive and force production. This low-repetition, high-load approach also benefits mobility by building strength through full range of motion with controlled heavy lifts (e.g., deep squats, overhead presses), enhancing end-range control and stability while reducing injury risk; full-ROM resistance training improves flexibility (range of motion) as effectively as stretching alone, while providing additional strength gains in lengthened positions that may reduce injury risk, and it proves more effective than high-repetition training for challenging mobility limitations without relying solely on progressive load increases; combining strength training with stretching is optimal for achieving large ROM improvements such as splits. Weekly volume per muscle group typically ranges from 10-20 sets for optimal in trained individuals, with starting lower to accommodate recovery needs. Frequency denotes the number of training sessions per muscle group or body part per week, influencing recovery and cumulative stimulus. For , 2-3 sessions per week per muscle group—often via full-body routines that balance all major muscle groups—is sufficient to stimulate adaptations without excessive fatigue. For beginners, particularly those beginning with bodyweight training at home or machine-based exercises at the gym, it is recommended to focus on proper form, performing 2-3 sets of 15-20 repetitions per exercise, with 48-72 hours of rest between sessions to ensure adequate recovery, and gradually increasing the load or difficulty through progressive overload. Intermediate trainees may benefit from 3-4 sessions, while advanced lifters can handle 4-5, provided volume is distributed to avoid . Training major muscle groups daily—such as in a routine consisting of 3 sets of compound lifts (e.g., squats, deadlifts, bench presses) plus planks—is generally not recommended for most individuals. Although compound lifts are highly effective for building strength and muscle and planks support core stability, performing them every day without rest days often results in insufficient recovery, increasing risks of overtraining, fatigue, stalled progress, and injury. Authoritative guidelines recommend strength training major muscle groups 2–3 days per week to allow adequate recovery. Such a daily routine could be suitable for beginners using very light loads, advanced trainees employing low volume or varied intensity, or specific programs, but for most people, incorporating rest days or using split routines (e.g., 3–4 days per week) is preferable for sustainable progress. , or the speed of repetition execution (typically notated as eccentric-pause-concentric-pause in seconds), further refines frequency's impact by controlling time under tension. A common tempo for balanced development is 2-1-2 (2 seconds eccentric, 1-second pause, 2 seconds concentric), which enhances muscle activation during both lengthening and shortening phases. Rest periods between sets modulate energy system involvement and performance. For muscular endurance, 30-90 seconds allows partial recovery while maintaining metabolic stress; hypertrophy benefits from 60-120 seconds to sustain moderate-intensity efforts; and strength training requires 3-5 minutes to replenish phosphocreatine stores for maximal lifts. Exercise order within a session prioritizes larger muscle groups and multi-joint movements first (e.g., squats before leg curls), as exercise order research shows earlier exercises yield higher reps, load, and volume, so prioritize the most important ones first. This sequence preserves energy for compound exercises that demand greater systemic effort and yields superior overall strength gains. In full body workouts, starting with lower body exercises ("legs first") allows for maximum performance on the most demanding compound lifts (e.g., squats, deadlifts) when energy and neural drive are highest, which is a common recommendation for strength-focused training. Alternating upper and lower exercises provides more recovery time between sets targeting the same body part, potentially allowing higher volume or better performance on subsequent sets of the same type, and is often used in hypertrophy-oriented or time-efficient full body routines. Many effective programs use hybrid approaches (e.g., lower-upper-lower) rather than strict alternation or all-lower-first. Proper breathing techniques stabilize and enhance force output during lifts. The standard approach is to exhale during the concentric () phase and inhale during the eccentric (release) phase, such as exhaling while pressing a upward and inhaling while lowering it, which prevents intra-abdominal pressure buildup and supports spinal integrity.

Periodization and Splits

Periodization refers to the systematic planning of athletic regimens to optimize and by varying variables such as , intensity, and over time. This approach aims to prevent training plateaus, manage , and allow for peaking at specific events, such as competitions, by aligning physiological adaptations with demands. Common models include linear, undulating, and block , each suited to different goals and levels. Linear involves a steady progression where decreases while intensity increases across mesocycles, typically spanning several weeks to months. For example, an initial phase with higher and moderate loads transitions to a strength phase with lower and higher loads, followed by a power phase. This model is effective for building foundational strength and preparing for events requiring peak performance, as it provides predictable progression and minimizes detraining risks, though it may lead to temporary declines in other qualities like power during the strength focus. A found linear periodization produces significant strength gains, comparable to other models when total is equated. Undulating periodization, in contrast, varies volume and intensity more frequently—often daily or weekly—within shorter cycles to enhance recovery and target multiple adaptations simultaneously. Daily undulating , for instance, might alternate high-volume/low-intensity days with low-volume/high-intensity days in the same week. Its purpose is to reduce monotony, accommodate individual recovery needs, and sustain , making it suitable for intermediate trainees or those prone to . Research indicates undulating models yield superior neuromuscular adaptations compared to non-periodized training, with meta-analyses showing no significant difference in overall strength gains versus linear approaches but better outcomes in some cases. Block periodization emphasizes concentrated training blocks focused on specific qualities, such as 2-6 weeks of high-volume accumulation followed by transmutation and realization phases with increasing intensity. This sequential structure leverages residual training effects to build targeted adaptations efficiently, ideal for athletes with multiple competitions or those needing rapid peaking. Unlike traditional models that balance multiple qualities concurrently, block periodization minimizes interference between adaptations, though it requires careful monitoring to avoid overload. Evidence from randomized trials supports its efficacy for strength and power gains, particularly in sports like and team athletics, where it outperforms non-blocked training in performance metrics. Training splits divide workouts to organize and across muscle groups, influencing recovery and overall program efficiency. Full-body splits, typically performed 3 times per week, train all major muscle groups in each session, allowing higher per muscle while keeping total weekly moderate. This approach benefits beginners or those with limited time, promoting balanced development and recovery due to distributed load, though it may limit per-session to avoid excessive . While full-body splits are typically scheduled 3 times per week to balance training stimulus with recovery, daily full-body compound lift routines without variation are generally inadvisable for most trainees. Such routines often result in insufficient recovery for major muscle groups, increasing the risks of overtraining, fatigue, stalled progress, and injury. Standard guidelines recommend training major muscle groups 2–3 times per week to optimize adaptations and minimize these risks. Upper/lower splits, often 4 days per week (two upper-body and two lower-body sessions), enable higher weekly per muscle group with adequate rest between similar sessions, supporting intermediate trainees focused on and strength without overwhelming recovery demands. The push-pull-legs (PPL) routine is a popular workout split among gym users, commonly used for its balanced approach to training major muscle groups. It divides workouts into three dedicated days: push days targeting chest, shoulders, and triceps with exercises like bench presses and overhead presses; pull days focusing on back and biceps with movements such as rows and pull-ups; and legs days emphasizing lower body muscles including quads, hamstrings, and calves through squats and deadlifts. This structure, often cycled over 3 or 6 days per week, maximizes volume and specificity for each muscle group while allowing for adequate recovery between sessions working similar muscles, promoting balanced development and reducing the risk of overuse injuries. PPL splits, usually 6 days per week, separate pushing muscles (e.g., chest, shoulders), pulling muscles (e.g., back, ), and legs into dedicated days, maximizing and specificity but requiring robust recovery capacity to handle the higher . Meta-analyses confirm that when weekly set is equated, full-body, upper/lower, and push/pull/legs splits produce similar strength and gains, with choices guided by individual recovery, schedule, and goals rather than inherent superiority. Deload weeks involve intentionally reducing intensity or , typically every 4-6 weeks for about 7 days, to facilitate supercompensation and mitigate accumulated . Methods include cutting sets by 50%, lowering loads to 50-70% of , or focusing on lighter accessory work, often planned within periodized cycles or adjusted autoregulatorily based on performance markers. This strategy enhances recovery, reduces risk, and improves subsequent preparedness by allowing physiological and psychological restoration. Expert consensus from coaches in strength sports supports deloads for sustaining long-term progress, with evidence indicating they prevent symptoms and boost adherence, though direct empirical studies remain limited.

Physiological Mechanisms

Aerobic Versus Anaerobic Exercise

Strength training primarily relies on anaerobic energy systems, which provide rapid bursts of energy without oxygen for high-intensity efforts lasting less than two minutes, such as weightlifting repetitions. These systems include the ATP-PC (adenosine triphosphate-phosphocreatine) pathway, which supplies immediate energy for the first 10-15 seconds of maximal effort by regenerating ATP from stored phosphocreatine in muscles, and anaerobic glycolysis, which breaks down glucose to produce ATP and lactate for activities up to about two minutes. In contrast, aerobic exercise depends on oxygen to metabolize carbohydrates and fats efficiently, generating ATP through oxidative phosphorylation for sustained efforts exceeding two minutes, such as running or cycling. The key differences lie in their physiological demands and adaptations: anaerobic in strength exercises enhances power output but is limited by the accumulation of lactate, which lowers the in muscles and contributes to during intense sets. This intermittent structure, including rest periods between sets for recovery, results in lower acute calorie expenditure compared to steady-state aerobic exercise of equivalent duration. Nonetheless, strength training excels in promoting muscle hypertrophy, which elevates resting metabolic rate and supports superior long-term energy expenditure. Aerobic , however, boosts maximal oxygen uptake (), improving endurance capacity by enhancing mitochondrial density and oxygen delivery to muscles. There is overlap in hybrid approaches like , which alternates strength movements with minimal rest to engage both systems, allowing for concurrent development of power and cardiovascular efficiency. Combining aerobic and anaerobic training yields complementary benefits, including greater fat loss through increased metabolic rate and improved , as well as enhanced —such as better endothelial function—without significantly impairing strength gains when properly sequenced. This integration supports overall fitness by leveraging anaerobic efforts for neuromuscular power while incorporating aerobic components to sustain for longer sessions.

Neuromuscular Adaptations

Strength training induces significant neuromuscular adaptations that enhance force production and muscle efficiency, primarily through changes in the and muscle structure. Early strength gains, often observed within the first few weeks of training, are largely attributed to neural adaptations rather than substantial muscle growth. These include increased , where more motor units are activated during a given effort; elevated firing rates of motor units, allowing for higher of contractions; and improved among motor units, leading to more coordinated and forceful muscle actions. Such neural efficiencies enable greater force output without initial , as evidenced by studies using to measure enhanced muscle activation and reduced antagonist co-activation. At the muscular level, strength training promotes , the increase in muscle fiber size, which contributes to long-term strength improvements. Strength training promotes primarily through the enlargement of myofibrillar proteins (contractile elements) within muscle fibers, leading to increases in both strength and size. Increases in sarcoplasmic volume (non-contractile elements like stores) may also occur, potentially supporting metabolic capacity, though the distinction between these is debated and not always clearly delineated in . Recent studies as of 2025 continue to explore training protocols aimed at emphasizing myofibrillar or sarcoplasmic , though results indicate overlapping effects on muscle growth and strength. These adaptations occur preferentially in type II fast-twitch fibers, which are recruited during high-intensity efforts. Strength training can also induce shifts in muscle fiber types, with a tendency toward increased type II fiber proportions or conversions from type IIX to type IIA subtypes, enhancing power and resistance without altering the overall slow-twitch (type I) dominance seen in activities. Hormonal responses play a key role in mediating these neuromuscular adaptations, with acute elevations in anabolic hormones following resistance exercise bouts. Testosterone and levels spike post-training by 10-20%, particularly after high-volume or high-intensity sessions involving compound multi-joint exercises such as squats, deadlifts, and bench presses, promoting protein synthesis and satellite cell activation necessary for ; these hormones also enhance lipolysis and fat oxidation. Consistent training protocols may contribute to long-term baseline increases in testosterone levels of 5-15% or 50-100 ng/dL in men, with benefits observable within weeks. These responses are influenced by factors such as load, volume, and rest intervals, with greater elevations observed in multi-joint exercises. However, overtraining can reverse these effects, leading to decreases in baseline testosterone levels. In contrast, excessive endurance training has been associated with reductions in baseline testosterone levels. Resistance training further promotes fat breakdown by stimulating muscle release of extracellular vesicles containing microRNAs, such as miR-1, which instruct adipose tissue to undergo lipolysis and release fatty acids for energy utilization. In older men, consistent resistance training may contribute to slowing the age-related decline in testosterone levels, potentially through preservation of muscle mass supporting androgen production, improved body composition reducing fat-related aromatization to estrogen, lowered chronic inflammation, and enhanced insulin sensitivity—which favors fat utilization over storage—though evidence for consistent basal level increases remains mixed.

Health and Performance Benefits

Effects on Muscles, Bones, and Body Composition

Strength training induces in fibers, primarily through type II fiber enlargement, leading to increased muscle cross-sectional area and overall mass. This results in firmer muscles and, when combined with nutrition to reduce body fat, potential visible muscle definition. This adaptation is optimized by high protein intake of approximately 1.6 g per kg body weight daily, which supports muscle protein synthesis, recovery, and growth. This adaptation enhances muscle strength and power, with meta-analyses showing gains of 20-40% in maximal strength after 8-12 weeks of progressive resistance programs in healthy adults. In older populations, such training effectively counters by preserving or increasing lean muscle mass, reducing the age-related loss that can exceed 1-2% annually after age 50. Strength training can help preserve and enhance muscle mass at any age. These muscular changes contribute to favorable shifts in , including reduced fat mass and improved muscle-to-fat ratios. Strength training burns approximately 200-400 kcal per 30-minute session of moderate intensity, with a moderate excess post-exercise oxygen consumption (afterburn) effect extending calorie expenditure. Long-term, gained muscle elevates resting metabolic rate, as each additional kg burns roughly 6-10 extra kcal daily compared to fat tissue. Consistent resistance training alone can decrease by 1-2% over 12-24 weeks, particularly when combined with moderate caloric control, while minimizing lean mass loss during weight reduction efforts. It yields fat loss effects comparable to aerobic exercise but excels in muscle preservation, with lower to moderate joint impact versus high-impact activities; 3-5 weekly sessions via full-body or split routines are recommended for these benefits, though for general health outcomes such as bone density, muscle maintenance, and metabolic function, it is not necessary to train each muscle group 2-3 times weekly—instead, consistent loading over years through sustainable routines providing sufficient stimulus, even at lower frequencies, promotes long-term adherence. Resistance training performed 3 days per week with heavy compound movements supports bone density and joint health through mechanical loading, improves metabolic health including insulin sensitivity and blood pressure regulation, and provides indirect cardiovascular benefits via improved body composition. Meta-analyses confirm that resistance protocols promote visceral fat reduction and overall fat-free mass preservation, outperforming in retaining muscle during energy deficits. On bones and connective tissues, bones and connective tissues such as tendons and ligaments strengthen under mechanical load; strength training applies heavy loads to bones via compound exercises, promoting direct osteogenic effects and adaptations in tendons and ligaments, consistent with , which posits that bone remodels in response to imposed loads, increasing density where forces are greatest. Systematic reviews indicate that high-intensity resistance exercises, such as or machine-based loading, elevate bone mineral density (BMD) by 1-3% at key sites like the lumbar spine and after 6-12 months, particularly in postmenopausal women and older adults at risk for . By stressing your bones, strength training can increase bone density and reduce the risk of osteoporosis. Benefits are further supported when combined with adequate dietary protein intake, which is associated with improved BMD and helps mitigate osteoporosis risk. This loading enhances joint stability by strengthening surrounding musculature, thereby reducing the risk of progression; longitudinal data show that regular strength training lowers the odds of radiographic knee osteoarthritis by 17-23% and mitigates degradation through improved . Regarding posture and frailty-related functionality, strength training bolsters core and postural muscles, improving spinal alignment and reducing slouching tendencies associated with weakened abdominal and back extensors. Core-focused protocols enhance stability during dynamic movements, correlating with better balance and a 20-30% lower incidence of falls in community-dwelling older adults over follow-up periods of 6-12 months. Grip strength, a proxy for overall upper-body function, shows a strong positive correlation (explaining 20-30% of variance) with physical performance metrics like mobility and activities of daily living in the elderly, with training-induced improvements predicting reduced frailty markers such as slow gait speed.

Effects on Longevity, Mortality, and Frailty

Strength training has been consistently linked to reduced all-cause mortality risk in large-scale epidemiological studies and meta-analyses. Strength exercises are considered the most beneficial for greater longevity and quality of life. A and of 16 prospective cohort studies involving over 480,000 participants found that engaging in muscle-strengthening activities, such as resistance exercise, was associated with a 10-17% lower risk of all-cause mortality, with maximum benefits at 30-60 minutes per week, alongside reductions in , cancer, , and mortality. Large cohort studies have also associated strength training with a 21% lower risk of all-cause mortality and a 34% reduction in cancer mortality risk. Similarly, a 2023 scientific statement from the , synthesizing data from multiple cohorts, reported that adults participating in resistance training experienced approximately 15% lower all-cause mortality and 17% lower mortality compared to non-participants. Resistance training 3 days per week with heavy compound movements contributes to these longevity markers by enhancing overall physiological resilience. An inverse dose-response relationship exists with muscle strength measures like ; meta-analyses indicate that each 5 kg increase in handgrip strength correlates with a 14-16% reduction in all-cause mortality risk across community-dwelling populations. No single standardized "longevity strength training index" or metric by that exact name exists. However, several evidence-based measures link muscle strength and mass to longevity outcomes and reduced mortality risk. Grip strength remains one of the strongest predictors of all-cause mortality, with meta-analyses confirming that a 5 kg decrease in grip strength is associated with approximately a 16% higher risk (HR 1.16, 95% CI 1.12-1.20). The appendicular lean mass index (ALMI), which measures limb skeletal muscle mass adjusted for height (kg/m²), is also associated with longevity; higher ALMI values correlate with lower all-cause mortality, with a 20-percentile increase linked to a 14% lower risk (HR 0.86, 95% CI 0.81-0.91). Functional performance tests, such as the five-repetition chair stand test, further assess muscle healthspan and are predictive of mortality and frailty risks in older adults, with poorer performance indicating higher vulnerability. While no universal consensus exists, longevity-focused discussions propose illustrative strength benchmarks, such as deadlifting approximately 1.5 times body weight, squatting 1.25 times body weight, bench pressing body weight, and maintaining grip strength above 35 kg for men and 20 kg for women, though these are examples rather than established scientific standards. Regarding , strength training supports cellular mechanisms that promote extended healthspan. Regular resistance exercise, particularly 1 hour or more per week, is associated with longer leukocyte lengths—a of biological aging—in U.S. adults, potentially slowing cellular aging by up to 4 years compared to sedentary individuals. This -protective effect may stem from reduced and enhanced pathways activated by resistance stimuli. Additionally, strength training improves mitochondrial function, increasing biogenesis and respiratory capacity, which counters age-related mitochondrial dysfunction and contributes to prolonged cellular and lifespan extension in cohort observations. These adaptations mediate broader benefits by preserving lean muscle mass, which buffers against and contributes to reduced biological aging, potentially equivalent to up to 4 fewer years of cellular aging. Strength training can help preserve and enhance muscle mass at any age. By stressing your bones, strength training can increase bone density and reduce the risk of osteoporosis. In terms of frailty, strength training effectively mitigates frailty progression in at-risk older populations, reducing the through gains in muscle power and functional capacity. A in obese older adults demonstrated that 18 months of resistance training, combined with , significantly improved physical function and reversed frailty status in 20-30% of participants, outperforming alone. Meta-analyses of intervention studies confirm that progressive resistance programs decrease frailty prevalence by enhancing lower-body strength and balance, with effect sizes indicating 20-40% improvements in frailty-related outcomes like speed and chair-rise performance in frail elderly groups. This leads to practical benefits, including up to 46% lower all-cause hospitalization rates among older adults engaging in consistent resistance-based exercise programs, as observed in prospective cohorts tracking post-intervention health events.

Neurobiological and Inflammatory Effects

Strength training induces neurobiological adaptations that promote brain health, primarily through the upregulation of (BDNF), a key protein involved in and . Systematic reviews and meta-analyses have demonstrated that resistance exercise significantly elevates circulating BDNF levels in healthy adults and those with neurological conditions, with effects observed after both acute bouts and chronic training programs lasting 8-12 weeks. Resistance training 3 days per week with heavy compound movements supports mental health outcomes through these mechanisms. These increases in BDNF support hippocampal , enhancing neuronal survival and connectivity, which contributes to overall cognitive resilience. Resistance training also yields cognitive benefits, particularly in such as selective attention, conflict resolution, and . A 12-month in older adults found that once- or twice-weekly resistance training improved executive cognitive performance compared to balance training, with sustained effects measurable via standardized tests like the Stroop task. Similarly, meta-analyses confirm moderate-intensity resistance exercise enhances and , with acute sessions showing immediate post-exercise improvements in young adults. On the mental health front, strength training reduces symptoms of depression and anxiety through neuroplastic mechanisms and mood regulation. A of randomized controlled trials reported a moderate (Hedges' g = 0.66) for resistance exercise in alleviating depressive symptoms, equivalent to approximately 30% reduction in severity scores on scales like the across diverse populations. For anxiety, systematic reviews indicate significant effects, with resistance training comparable to in clinical and healthy groups, particularly when performed 2-3 times weekly for 8-12 weeks. In terms of inflammatory effects, strength training modulates chronic by lowering pro-inflammatory markers such as (CRP) and interleukin-6 (IL-6). Meta-analyses of older adults show resistance training reduces CRP levels with a standardized mean difference of -0.61 after 12-24 weeks, independent of changes, with modest but non-significant effects on IL-6 (SMD -0.25). This anti-inflammatory action is mediated by myokines like irisin, released from contracting , which inhibits pro-inflammatory pathways (e.g., ) and promotes anti-inflammatory cytokines such as IL-10. Additionally, strength training mitigates , a contributor to aging-related , by enhancing activity (e.g., ) and reducing , as evidenced in systematic reviews of chronic training protocols. Strength training favorably influences lipid profiles, with meta-analyses indicating small improvements such as increases in high-density lipoprotein (HDL) cholesterol (effect size 0.36) and decreases in low-density lipoprotein (LDL) cholesterol (effect size -0.45), though these effects are generally smaller than those from aerobic exercise and vary by population. In postmenopausal women, resistance training has been associated with LDL reductions of approximately 8.5 mg/dL but slight decreases in HDL of about 3 mg/dL after interventions. Emerging 2024 research highlights the role of strength training in modulating the gut-brain axis via alterations in microbiota composition, which may indirectly support neuroinflammation reduction and cognitive health through short-chain fatty acid production.

Impacts on Sports Performance and Posture

Strength training significantly enhances performance by increasing power output, as evidenced by meta-analyses showing moderate to large s on key metrics such as height. In female adolescent athletes, strength training programs yield a moderate of 0.74 (95% CI: 0.31–1.17) on performance, often translating to improvements of 10–20% in jump height depending on program duration and frequency. These gains are particularly pronounced with programs lasting 10 weeks or more at ≤2 sessions per week, enabling greater neuromuscular recruitment for explosive movements. Consistent strength training also improves posture by strengthening core and back muscles, promoting better spinal alignment. Beyond power metrics, strength training contributes to in by fortifying tendons and improving joint stability, notably reducing (ACL) injury risk. Systematic reviews indicate that training interventions, including core strengthening, decrease knee injury incidence by 25% (RR = 0.75, 95% CI: 0.65–0.85), with optimal effects from sessions of 5–15 minutes performed 4–5 times weekly over >26 weeks. This protective mechanism involves enhanced hamstring-quadriceps co-activation and reduced knee valgus angles during dynamic activities, thereby stabilizing the ACL. In terms of posture, balanced strength training programs exert corrective effects by addressing muscular imbalances and promoting spinal alignment. Targeted spine-strengthening exercises combined with posture training reduce thoracic by approximately 3° as measured by (95% CI: -5.2 to -0.8) and kyphometer in older adults over 6 months. Core exercises further support this by enhancing trunk stability and reducing or rounded shoulders, leading to improved overall postural alignment without adverse effects on physical function. For at-risk populations such as the elderly or those in rehabilitation, strength training improves , aiding balance and reducing fall risk through better joint position sense and neuromuscular coordination. Programs incorporating functional strength exercises over 12 weeks (3 sessions/week, 45 minutes each) enhance gait stability and lower limb control, with proprioceptive components targeting locomotion and level changes to boost postural feedback. Recent advancements as of 2025 integrate for real-time posture tracking in athletes, enhancing strength training outcomes and . Inertial measurement units (), the most common sensors, enable motion analysis for detecting postural deviations during training, with 47% of applications focused on rehabilitation and 44% on assessment, particularly for lower limb issues like sprains. These devices provide to correct form, supporting sustained performance improvements in sports contexts.

Nutrition and Recovery

Nutritional Requirements

Strength training imposes specific nutritional demands to support muscle repair, energy provision, and overall . Adequate of macronutrients is essential for optimizing protein synthesis, replenishment, and hormonal balance in resistance-trained individuals. Protein requirements for strength training typically range from 1.6 to 2.2 grams per of body weight per day to maximize muscle protein synthesis, , recovery, and growth. This intake supports the muscle mass increases induced by strength training; when combined with resistance exercise, high protein consumption (at least 1.6 g/kg) also enhances bone density and reduces osteoporosis risk by aiding bone matrix formation alongside mechanical loading. This recommendation accounts for the increased demands of resistance exercise, where intakes below 1.6 g/kg may limit gains in lean mass, while exceeding 2.2 g/kg offers minimal additional benefits for most athletes. Higher-quality sources, such as or soy, are prioritized for their complete profiles to enhance recovery and . Carbohydrates serve as the source for high-intensity strength sessions, with recommended intakes of 4 to 7 grams per of body weight per day to maintain stores and support training volume. This range allows for sustained performance during repeated bouts of resistance exercise, particularly in programs involving multiple sets and moderate repetitions. Dietary fats should constitute 20 to 30 percent of total daily calories to support production, including testosterone, which is crucial for muscle growth in strength athletes. This level ensures intake without compromising or protein allocation, promoting overall metabolic health. Nutrient timing plays a key role in enhancing training outcomes, with 20 to 40 grams of protein consumed in the pre- and post-workout windows to stimulate muscle protein synthesis and reduce breakdown. For those aiming to build muscle mass, a moderate calorie surplus of 300 to 500 kilocalories above daily supports without excessive fat gain, while a controlled deficit facilitates fat loss during cutting phases. Proper also aids recovery processes during rest periods between sessions. Micronutrients are vital for supporting the physiological stresses of strength training, including bone integrity and oxygen transport. Calcium and intakes of 1,000 to 1,200 milligrams and 600 to 2,000 international units per day, respectively, promote and reduce risk in activities. Iron, at 8 to 18 milligrams daily depending on and training intensity, is essential for formation and preventing fatigue from impaired oxygen delivery. Recent analyses indicate that plant-based diets can meet these needs for strength athletes through fortified foods and diverse sources, without compromising when total protein and targets are achieved.

Supplementation and Hydration

Supplementation in strength training often involves compounds that support energy production, muscle recovery, and performance during high-intensity efforts. Creatine monohydrate is one of the most researched ergogenic aids, primarily enhancing stores to replenish (ATP) for short-duration, maximal efforts. A maintenance dose of 3-5 grams per day, following an optional loading phase of 20 grams per day for 5-7 days, has been shown to increase upper- and lower-body strength gains more than resistance training alone in various populations. A 2024 confirmed these benefits, particularly in adults under 50 years old during resistance training protocols. Protein supplementation, such as isolates or concentrates, provides a rapidly absorbed source of essential amino acids to stimulate muscle protein synthesis post-exercise, complementing dietary protein intake. Consuming 20-40 grams of immediately after training sessions has been associated with greater increases in mass and handgrip strength compared to in older adults engaging in resistance exercise. Beta-alanine supplementation, typically at 4-6 grams per day for 2-4 weeks, elevates muscle levels to buffer hydrogen ions during intense contractions, thereby improving exercise capacity in efforts lasting 1-4 minutes. The International Society of position stand notes consistent performance enhancements in high-intensity activities relevant to strength training. Emerging research on supplementation, often from juice providing 5-8 millimoles of nitrate, shows potential to modestly boost muscle power output in resistance exercises, particularly in females, by improving vascular function and oxygen . A systematic review indicated small ergogenic effects on power but no significant improvements in overall muscle strength across doses tested. Hydration is critical for maintaining performance and recovery in strength training, as even mild can impair strength output and increase . Baseline daily fluid intake for active adults is recommended at 3-4 liters, adjusted upward based on body size, climate, and sweat rate, with athletes targeting 5-7 milliliters per kilogram of body weight per hour during sessions to replace losses. During training lasting over 60 minutes, consuming 400-800 milliliters per hour, including electrolytes like sodium (300-600 milligrams per liter) and , helps preserve balance and prevent muscle cramps. The emphasizes monitoring urine color and body weight pre- and post-exercise to ensure losses stay below 2% of body mass. Safety considerations for these supplements include adhering to evidence-based dosing to minimize side effects. at recommended levels is safe for up to five years in healthy individuals, with rare gastrointestinal upset or water retention, though those with conditions should consult a physician. and beta-alanine are generally well-tolerated, but (tingling) from beta-alanine can be mitigated by dividing doses. Interactions are minimal, but combining with high intake (over 300 milligrams) may slightly attenuate strength benefits in some users due to potential interference with creatine uptake. supplements pose low risk but may cause mild gastrointestinal discomfort at higher doses. Always verify purity through third-party testing and integrate supplements under professional guidance to avoid excesses.

Historical Development

Origins and Early Practices

The earliest evidence of strength training practices dates back to ancient civilizations around 3000 BCE, where physical conditioning was integral to survival, warfare, and ritual. In Minoan Crete, artifacts such as frescoes from depict wrestling and activities that required exceptional strength and agility, suggesting these were formalized training methods for young participants in athletic and possibly initiatory rites. Similarly, in ancient , malla-yuddha, a form of combat wrestling, emerged as early as 3000 BCE, incorporating techniques and bodyweight exercises to build power and endurance, as evidenced by archaeological depictions in South Asian regions including modern-day and . These practices emphasized functional strength for combat and cultural displays rather than isolated muscle development. In and , strength training evolved further with legendary figures and structured regimens tied to military prowess. The wrestler , active in the 6th century BCE, is renowned for carrying a newborn calf daily until it grew into a full-grown , exemplifying the principle of —a gradual increase in resistance to build strength—that remains foundational today. This anecdote, preserved in historical accounts, underscores how Greek athletes trained for Olympic events like , combining wrestling and striking to enhance overall power. Roman gladiators, trained in ludus schools from the 3rd century BCE onward, followed rigorous programs including with (dumbbell-like tools), running, and weighted weapon drills to prepare for arena , as described by physicians like who advocated balanced conditioning for endurance and force. During the Middle Ages, strength training persisted through knightly preparation and Eastern traditions, often linked to feudal warfare and physical feats. European knights underwent intensive regimens from childhood, including lifting heavy stones, swinging weighted weapons, and performing armored to develop the power needed for mounted and sieges, as outlined in medieval manuals emphasizing practical over aesthetics. In Persia and , Indian clubs (meels or muggars), wooden or stone implements swung in circular patterns, were used by wrestlers and warriors since at least the 5th century BCE to cultivate rotational strength and coordination, with roots in Zoroastrian for military readiness. These tools, documented in ancient texts, facilitated dynamic exercises that improved grip, stability, and full-body power. By the , a cultural shift in began transitioning strength displays from purely military or survival-oriented purposes to performative and aesthetic spectacles, influenced by Enlightenment ideals of the body as a harmonious form. Strongmen like Thomas Topham, active in the 1740s, captivated audiences with feats such as lifting 224-pound weights or pulling carts with their hair, blending raw power with theatricality in public shows that popularized beyond battlefields. This evolution culminated in the with , dubbed the "father of modern ," who in the organized posing exhibitions in , such as the 1901 Great Competition, shifting focus to muscular symmetry and visual appeal through progressive resistance methods. Sandow's performances, drawing thousands, marked the emergence of strength training as a pursuit of idealized physique, distinct from earlier utilitarian applications.

Modern Evolution and Research

The formalization of Olympic weightlifting occurred at the first modern in in 1896, where it debuted as one of the original sports, though initial events lacked standardized weight classes or lifts. In the mid-20th century, bodybuilding pioneer developed foundational training principles in the 1940s, emphasizing and split routines to promote muscle growth, which became central to modern practices. Concurrently, during , U.S. Army physician Thomas L. introduced progressive resistance exercise in 1945 as a rehabilitation method for injured servicemen, using multiple sets of 10-repetition maximum loads that evolved into a structured three-set protocol by 1948, significantly shortening recovery times and establishing concepts in clinical settings. The founding of the National Strength and Conditioning Association (NSCA) in 1978 marked a pivotal milestone in professionalizing strength training research and education, providing peer-reviewed journals and certifications that bridged scientific inquiry with practical application. In the , meta-analyses advanced evidence-based programming; for instance, a 2003 review by Rhea et al. demonstrated that periodized training programs yielded superior strength and power gains compared to non-periodized approaches across diverse populations, influencing widespread adoption in athletic and rehabilitative contexts. Later meta-analyses examining dose-response relationships quantified optimal training volumes for , showing that at least 10 weekly sets per muscle group maximized muscle growth without excessive fatigue. By the late 20th and early 21st centuries, strength training's global spread accelerated with greater inclusion of women, spurred by the 1972 enactment of in the U.S., which prohibited sex-based discrimination in education and dramatically increased female participation in school and collegiate sports, including resistance programs. This momentum culminated in women's debut at the 2000 Sydney Games, standardizing female categories and promoting gender equity in the sport. The 2000s also saw the rise of modalities, exemplified by , founded in 2000 by Greg Glassman, which integrated high-intensity Olympic lifts, , and metabolic conditioning to emphasize broad fitness adaptability and community-driven workouts. Recent advancements from 2024 to 2025 have incorporated for program design, with a 2025 study assessing AI-generated resistance training plans for hypertrophy and strength as providing moderate-quality frameworks as rated by experienced coaches, offering a useful initial structure but requiring expert supervision for individualization and safety. , originating in in the 1960s but gaining traction through 21st-century meta-analyses, enables significant at low loads (20-30% of 1RM) by occluding venous return, offering benefits for rehabilitation and older adults while minimizing joint stress.

Considerations for Subpopulations

Children and Adolescents

Strength training for children and adolescents, when properly supervised, can be a safe and effective component of physical development, with guidelines emphasizing age-appropriate progression to support growth without compromising safety. The (AAP) recommends initiating resistance training as early as ages 5 to 7 years for children who demonstrate sufficient maturity, focusing on bodyweight exercises to build foundational skills rather than heavy loads. Supervision by qualified professionals, such as those certified by the National Strength and Conditioning Association, is crucial to provide real-time feedback and maintain appropriate instructor-to-participant ratios, ensuring proper technique takes precedence over maximal efforts to minimize injury risk. Among the key benefits, strength training enhances density during the critical growth periods of childhood and , when skeletal loading can optimize peak bone mass accrual. Programs incorporating resistance exercises have been shown to increase bone strength index and overall mineralization, particularly when combined with weight-bearing activities. Additionally, it promotes development and physical , improving coordination, balance, and overall movement proficiency in young participants. Recommended programs for this population typically involve 2 to 3 sessions per week, lasting 20 to 30 minutes, with 1 to 2 sets of 8 to 12 repetitions using bodyweight, free weights, or machines at moderate intensities (≤60% of initially). Progression should be gradual, incorporating dynamic warm-ups, core exercises, and adequate rest periods, with optimal gains observed after 8 to 12 weeks or longer durations exceeding 23 weeks. In prepubertal children, adaptations are primarily neurologic, enhancing strength through improved rather than . Despite these advantages, risks arise from improper implementation, including overuse injuries such as muscle strains, , or hand injuries, which are more common with excessive loads or insufficient recovery. For instance, repetitive stress in can lead to conditions like Little League elbow (medial epicondyle apophysitis), an overuse injury to the elbow's growth plate often seen in throwing athletes. Common myths, such as the notion that strength training stunts linear growth or damages growth plates, have been debunked; well-designed programs show no adverse effects on height or skeletal development. During , monitoring is essential as hormonal changes shift training responses toward hypertrophic gains, requiring adjustments in volume and intensity based on individual maturation and training experience to prevent .

Sex Differences in Adults

Adult men and women exhibit notable physiological differences in strength training outcomes, primarily driven by hormonal variations. Women typically have 10-15 times lower circulating testosterone levels than men. This contributes to a baseline strength disparity, particularly in the upper body where women typically demonstrate 40-50% lower absolute strength (or about 50-60% of men's levels). Despite this, both sexes experience similar relative gains in strength and muscle mass when normalized to baseline levels, indicating that training adaptations are comparably effective across genders. Muscle hypertrophy responses to resistance training are equivalent between men and women, challenging earlier assumptions of diminished growth in females. Studies show that women achieve proportional increases in muscle cross-sectional area with , often matching or exceeding men's relative improvements in strength per unit of muscle mass. Programming for should thus emphasize similar volumes and frequencies for both sexes, though initial loads for women may need adjustment to 40-50% lower than men's to account for baseline differences, particularly in upper-body exercises. Women may also tolerate higher volumes due to greater resistance, allowing for extended sets without proportional strength loss. The introduces phase-specific variations in women's training performance, with the —marked by rising —often associated with peak strength and power output. Research indicates that anaerobic capacity and maximal lifts are optimized during this early cycle stage, potentially due to enhanced neuromuscular efficiency, while the may slightly impair recovery or . However, long-term adaptations to training programs remain unaffected by cycle phase, supporting consistent programming without mandatory around . Socio-cultural factors have historically limited women's participation in strength training, including myths that heavy lifting causes excessive bulking or is unsuitable for females, which deter access and equity. These misconceptions stem from traditional roles and overlook women's capacity for lean muscle gains without masculinization, as lower testosterone prevents the same hypertrophic extremes seen in men. Recent from 2025 highlight progress in female , where participation has surged to nearly 31% of competitors, and records show women achieving 46-64% of male totals, narrowing performance gaps through increased access and debunked . Strength training considerations for and non-binary individuals involve accounting for effects on muscle adaptations and recovery. For women on therapy, strength gains may be moderated compared to women, while men on testosterone may experience enhanced similar to men; individualized programming and medical consultation are recommended to optimize safety and efficacy.

Older Adults

Strength training offers significant benefits for older adults, helping to counteract age-related declines in muscle mass and function known as . Research spanning over 40 years demonstrates that it increases muscle strength and mass, improves motor function, and reduces frailty, with higher training intensities producing greater adaptations, including through heavy resistance training which effectively builds muscle strength. For instance, progressive resistance exercises at 60–85% of (1RM) can lead to and enhanced neuromuscular efficiency after 6–9 weeks, preserving independence and mobility. In addition to physical gains, strength training enhances , reducing risk and fracture incidence, particularly when combined with activities like weighted vests. It also improves metabolic health by boosting fat and glucose processing, combating sarcopenic , supporting overall vitality, and reducing risks of cardiovascular disease, diabetes, and cancer mortality. Meta-analyses confirm improvements in domains such as physical functioning (standardized mean difference [SMD] 0.31), , and reduced depression (SMD -1.13), alongside gains in upper- and lower-limb strength (mean differences of 15.26 kg and 48.46 kg, respectively). These effects extend to better balance, , and , lowering fall risk by up to 32–40% when integrated with . Guidelines from authoritative bodies recommend 2–3 sessions per week on non-consecutive days, targeting major muscle groups with multijoint exercises. Programs should start at moderate intensity (40–60% 1RM for beginners, progressing to 60–80% 1RM), involving 2–3 sets of 8–12 repetitions to build strength and power without excessive fatigue. The National Strength and Conditioning Association (NSCA) emphasizes individualized progression, such as 5–10% load increases as tolerated, and inclusion of power-focused movements (e.g., 40–60% 1RM at higher speeds) for functional improvements. The Centers for Disease Control and Prevention (CDC) outlines phased programs beginning with bodyweight exercises like squats and wall push-ups, advancing to dumbbells for curls and presses, to ensure safe adaptation over 12 weeks or more. Safety is paramount, as older adults may face higher risks from overuse or improper form, particularly with conditions like or . Medical clearance is advised for those with chronic illnesses, and training should avoid the to prevent spikes; supervised sessions with proper spotting minimize risks while maximizing benefits. Evidence shows that well-designed programs are safe and effective even for frail individuals, yielding 15–30% strength gains without adverse events when starting slowly and monitoring progress.

References

  1. https://www.ncbi.nlm.nih.gov/mesh/68055070
  2. https://pmc.ncbi.nlm.nih.gov/articles/PMC5532191/
  3. https://pmc.ncbi.nlm.nih.gov/articles/PMC5983157/
  4. https://www.mayoclinic.org/healthy-lifestyle/fitness/in-depth/strength-training/art-20046670
  5. https://www.mayoclinic.org/healthy-lifestyle/fitness/in-depth/strength-training/art-20046031
  6. https://pubmed.ncbi.nlm.nih.gov/31104484/
  7. https://pubmed.ncbi.nlm.nih.gov/28549705/
  8. https://www.bmj.com/content/361/bmj.k1651
  9. https://www.cdc.gov/mmwr/preview/mmwrhtml/mm5528a1.htm
  10. https://pubmed.ncbi.nlm.nih.gov/29372481/
  11. https://www.cdc.gov/physical-activity-basics/benefits/index.html
  12. https://www.cdc.gov/physicalactivity/downloads/growing_stronger.pdf
  13. https://www.cdc.gov/mmwr/preview/mmwrhtml/mm5302a1.htm
  14. https://www.cdc.gov/physical-activity-basics/health-benefits/older-adults.html
  15. https://www.cdc.gov/pcd/issues/2020/19_0408.htm
  16. https://www.cdc.gov/physical-activity/features/boost-brain-health.html
  17. https://acsm.org/education-resources/trending-topics-resources/physical-activity-guidelines/
  18. https://www.cdc.gov/physical-activity-basics/guidelines/adults.html
  19. https://www.mayoclinic.org/healthy-lifestyle/fitness/in-depth/weight-training/art-20045842
  20. https://acsm.org/top-fitness-trends-2025/
  21. https://www.prescriptiontogetactive.com/static/pdfs/resistance-training-ACSM.pdf
  22. https://www.nsca.com/contentassets/de9aebfe7a7340b69217b99bb13862a7/basics_of_strength_and_conditioning_manual.pdf
  23. https://ouhsc.edu/bserdac/dthompso/web/namics/mmaction.htm
  24. https://www.usapowerlifting.com/wp-content/uploads/2023/09/USAPL-Rulebook-v2023.1.pdf
  25. https://www.usaweightlifting.org/weightlifting101/the-lifts
  26. https://pmc.ncbi.nlm.nih.gov/articles/PMC6162410/
  27. https://pmc.ncbi.nlm.nih.gov/articles/PMC7927075/
  28. https://pmc.ncbi.nlm.nih.gov/articles/PMC9528903/
  29. https://www.govinfo.gov/content/pkg/GOVPUB-HE20_100-PURL-gpo42233/pdf/GOVPUB-HE20_100-PURL-gpo42233.pdf
  30. https://journals.lww.com/acsm-csmr/fulltext/2019/04000/sports_training_principles.2.aspx
  31. https://pmc.ncbi.nlm.nih.gov/articles/PMC11057610/
  32. https://www.scienceforsport.com/force-velocity-curve/
  33. https://pmc.ncbi.nlm.nih.gov/articles/PMC8449772/
  34. https://pubmed.ncbi.nlm.nih.gov/32358310/
  35. https://paulogentil.com/pdf/A%2520critical%2520analysis%2520of%2520the%2520ACSM%2520position%2520stand%2520on%2520resistance%2520training.pdf
  36. https://bmcsportsscimedrehabil.biomedcentral.com/articles/10.1186/s13102-023-00713-4
  37. https://www.hprc-online.org/physical-fitness/training-performance/choosing-right-exercises-optimize-your-resistance-training
  38. https://pubmed.ncbi.nlm.nih.gov/19204579/
  39. https://www.nsca.com/education/articles/kinetic-select/determination-of-resistance-training-frequency/
  40. https://pmc.ncbi.nlm.nih.gov/articles/PMC9935664/
  41. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8067745/
  42. https://www.bodyspec.com/blog/post/strength_training_for_beginners
  43. https://www.acefitness.org/continuing-education/certified/april-2025/8843/repetition-tempo-and-muscular-development-what-s-the-connection/
  44. https://pmc.ncbi.nlm.nih.gov/articles/PMC8310485/
  45. https://pubmed.ncbi.nlm.nih.gov/19691365/
  46. https://journals.lww.com/nsca-jscr/fulltext/2010/11000/influence_of_exercise_order_on_maximum_strength.10.aspx
  47. https://us.humankinetics.com/blogs/excerpt/utilize-proper-workout-structure-and-exercise-order
  48. https://www.healthline.com/health/fitness-exercise/when-to-inhale-and-exhale-during-exercise
  49. https://pmc.ncbi.nlm.nih.gov/articles/PMC4637911/
  50. https://pubmed.ncbi.nlm.nih.gov/25268290/
  51. https://journals.lww.com/nsca-jscr/abstract/2002/05000/a_comparison_of_linear_and_daily_undulating.13.aspx
  52. https://pmc.ncbi.nlm.nih.gov/articles/PMC9987427/
  53. https://journals.lww.com/nsca-jscr/fulltext/2021/08000/periodization_and_block_periodization_in_sports_.39.aspx
  54. https://doi.org/10.1519/JSC.0000000000004050
  55. https://pmc.ncbi.nlm.nih.gov/articles/PMC8372753/
  56. https://pubmed.ncbi.nlm.nih.gov/38595233/
  57. https://pmc.ncbi.nlm.nih.gov/articles/PMC9107721/
  58. https://www.muscleandstrength.com/workouts/3-day-PPL-workout-for-beginners
  59. https://www.aston.ac.uk/sport/news/tips/fitness-exercise/push-pull-legs
  60. https://pmc.ncbi.nlm.nih.gov/articles/PMC10511399/
  61. https://doi.org/10.1186/s40798-023-00633-0
  62. https://www.acefitness.org/fitness-certifications/ace-answers/exam-preparation-blog/3256/the-three-primary-energy-pathways-explained/
  63. https://pressbooks.library.vcu.edu/biol217vcu/chapter/10b-fuel-sources-exercise/
  64. https://pubmed.ncbi.nlm.nih.gov/25162652/
  65. https://pmc.ncbi.nlm.nih.gov/articles/PMC5329739/
  66. https://pmc.ncbi.nlm.nih.gov/articles/PMC5154721/
  67. https://pdxscholar.library.pdx.edu/cgi/viewcontent.cgi?article=1448&context=honorstheses
  68. https://link.springer.com/article/10.2165/00007256-200737020-00004
  69. https://pmc.ncbi.nlm.nih.gov/articles/PMC7372125/
  70. https://www.researchgate.net/publication/393279745_The_Effect_of_Myofibril_and_Sarcoplasmic_Hypertrophy_Training_on_Muscle_Hypertrophy_and_Strength
  71. https://link.springer.com/article/10.1007/BF00572189
  72. https://journals.lww.com/nsca-jscr/fulltext/2012/06000/the_effects_of_endurance%2C_strength%2C_and_power.37.aspx
  73. https://pmc.ncbi.nlm.nih.gov/articles/PMC4461225/
  74. https://journals.physiology.org/doi/full/10.1152/japplphysiol.00565.2005
  75. https://pmc.ncbi.nlm.nih.gov/articles/PMC7739287/
  76. https://pmc.ncbi.nlm.nih.gov/articles/PMC3435910/
  77. https://pubmed.ncbi.nlm.nih.gov/21058750/
  78. https://pmc.ncbi.nlm.nih.gov/articles/PMC5988228/
  79. https://link.springer.com/article/10.2165/00007256-200535040-00004
  80. https://pubmed.ncbi.nlm.nih.gov/20847704/
  81. https://insight.jci.org/articles/view/182589
  82. https://diabetesjournals.org/diabetes/article/52/9/2191/11503/Enhanced-Fat-Oxidation-Through-Physical-Activity
  83. https://jissn.biomedcentral.com/articles/10.1186/s12970-017-0177-8
  84. https://academic.oup.com/ageing/article/51/2/afac003/6527381
  85. https://journals.lww.com/nsca-jscr/fulltext/2019/08000/resistance_training_for_older_adults__position.1.aspx
  86. https://pmc.ncbi.nlm.nih.gov/articles/PMC8588688/
  87. https://www.health.harvard.edu/diet-and-weight-loss/calories-burned-in-30-minutes-for-people-of-three-different-weights
  88. https://pmc.ncbi.nlm.nih.gov/articles/PMC8439678/
  89. https://inbodyusa.com/blogs/inbodyblog/muscle-vs-fat-weight/
  90. https://pmc.ncbi.nlm.nih.gov/articles/PMC12107660/
  91. https://pubmed.ncbi.nlm.nih.gov/21694556/
  92. https://pubmed.ncbi.nlm.nih.gov/28975661/
  93. https://onlinelibrary.wiley.com/doi/abs/10.1111/obr.13256
  94. https://pmc.ncbi.nlm.nih.gov/articles/PMC9285060/
  95. https://bmjopensem.bmj.com/content/11/3/e002363
  96. https://pubmed.ncbi.nlm.nih.gov/3633121/
  97. https://www.nature.com/articles/s41598-025-93642-w
  98. https://pmc.ncbi.nlm.nih.gov/articles/PMC6279907/
  99. https://pubmed.ncbi.nlm.nih.gov/35742181/
  100. https://acrjournals.onlinelibrary.wiley.com/doi/10.1002/art.42732
  101. https://pmc.ncbi.nlm.nih.gov/articles/PMC6110226/
  102. https://pmc.ncbi.nlm.nih.gov/articles/PMC8304136/
  103. https://pmc.ncbi.nlm.nih.gov/articles/PMC6778477/
  104. https://bjsm.bmj.com/content/56/13/755
  105. https://www.ahajournals.org/doi/10.1161/CIR.0000000000001189
  106. https://pmc.ncbi.nlm.nih.gov/articles/PMC9923435/
  107. https://www.nature.com/articles/s41598-025-94357-8
  108. https://pmc.ncbi.nlm.nih.gov/articles/PMC11591842/
  109. https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2017.00713/full
  110. https://www.nejm.org/doi/full/10.1056/NEJMoa1616338
  111. https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2792175
  112. https://www.medscape.com/viewarticle/exercise-cuts-hospitalization-risk-older-adults-2024a1000g7q
  113. https://www.sciencedirect.com/science/article/abs/pii/S0197457223002148
  114. https://pmc.ncbi.nlm.nih.gov/articles/PMC10389831/
  115. https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2024.1505879/full
  116. https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/415534
  117. https://sportsmedicine-open.springeropen.com/articles/10.1186/s40798-022-00527-7
  118. https://bjsm.bmj.com/content/59/12/866
  119. https://jamanetwork.com/journals/jamapsychiatry/fullarticle/2680311
  120. https://www.sciencedirect.com/science/article/pii/S016517812300272X
  121. https://pubmed.ncbi.nlm.nih.gov/40432290/
  122. https://pubmed.ncbi.nlm.nih.gov/30071283/
  123. https://pubmed.ncbi.nlm.nih.gov/38941946/
  124. https://www.sciencedirect.com/science/article/abs/pii/S0303720722001241
  125. https://pmc.ncbi.nlm.nih.gov/articles/PMC10084474/
  126. https://pmc.ncbi.nlm.nih.gov/articles/PMC11117672/
  127. https://onlinelibrary.wiley.com/doi/10.1155/2021/1947928
  128. https://pubmed.ncbi.nlm.nih.gov/31023184/
  129. https://www.sciencedirect.com/science/article/abs/pii/S0301211523002658
  130. https://pmc.ncbi.nlm.nih.gov/articles/PMC10763211/
  131. https://link.springer.com/article/10.1186/s12982-024-00138-5
  132. https://pmc.ncbi.nlm.nih.gov/articles/PMC12131141/
  133. https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2025.1455055/full
  134. https://pmc.ncbi.nlm.nih.gov/articles/PMC5873977/
  135. https://pmc.ncbi.nlm.nih.gov/articles/PMC10815388/
  136. https://pmc.ncbi.nlm.nih.gov/articles/PMC11780775/
  137. https://jissn.biomedcentral.com/articles/10.1186/s12970-017-0189-4
  138. https://pmc.ncbi.nlm.nih.gov/articles/PMC3562955/
  139. https://jissn.biomedcentral.com/articles/10.1186/s12970-017-0174-y
  140. https://www.eatright.org/fitness/sports-and-athletic-performance/advanced/vitamin-needs-of-athletes
  141. https://pmc.ncbi.nlm.nih.gov/articles/PMC12130401/
  142. https://pubmed.ncbi.nlm.nih.gov/12485548/
  143. https://jissn.biomedcentral.com/articles/10.1186/s12970-017-0173-z
  144. https://pubmed.ncbi.nlm.nih.gov/39519498/
  145. https://pubmed.ncbi.nlm.nih.gov/37571361/
  146. https://pubmed.ncbi.nlm.nih.gov/26175657/
  147. https://pmc.ncbi.nlm.nih.gov/articles/PMC12471447/
  148. https://link.springer.com/article/10.1007/s00421-025-05779-1
  149. https://pubmed.ncbi.nlm.nih.gov/17277604/
  150. https://www.mayoclinic.org/drugs-supplements-creatine/art-20347591
  151. https://www.fhw.gr/olympics/ancient/en/102.html
  152. https://www.ancient-origins.net/history-ancient-traditions/ancient-martial-arts-0011053
  153. https://pmc.ncbi.nlm.nih.gov/articles/PMC10625844/
  154. https://oasis.library.unlv.edu/cgi/viewcontent.cgi?article=2283&context=rtds
  155. https://www.english-heritage.org.uk/visit/inspire-me/how-the-romans-kept-fit
  156. https://www.metmuseum.org/essays/gladiators-types-and-training
  157. https://historicalfencer.com/how-to-train-like-a-knight-from-medieval-times/
  158. https://www.setforset.com/blogs/news/the-complete-guide-to-indian-clubs-history-benefits-sizes
  159. https://www.mentalfloss.com/article/58564/12-feats-strength-1700s-strongman
  160. https://barbend.com/first-bodybuilding-show-eugen-sandow/
  161. https://www.roguefitness.com/theindex/documentaries/sandow
  162. https://www.usaweightlifting.org/news/2024/may/28/the-history-of-olympic-weightlifting
  163. https://www.muscleandfitness.com/workouts/workout-tips/weider-principles-2/
  164. https://pubmed.ncbi.nlm.nih.gov/22592167/
  165. https://www.nsca.com/
  166. https://pubmed.ncbi.nlm.nih.gov/15673040/
  167. https://pubmed.ncbi.nlm.nih.gov/27433992/
  168. https://www.ncaa.org/news/2022/6/23/features-the-origins-of-title-ix.aspx
  169. https://iwf.sport/2020/09/22/20-years-anniversary-female-inclusion-weightlifting-olympic-games/
  170. https://www.revivalfitnessmd.com/history-of-crossfit/
  171. https://pmc.ncbi.nlm.nih.gov/articles/PMC12492345/
  172. https://pmc.ncbi.nlm.nih.gov/articles/PMC8674694/
  173. https://pmc.ncbi.nlm.nih.gov/articles/PMC3445252/
  174. https://pubmed.ncbi.nlm.nih.gov/11019731/
  175. https://www.nationwidechildrens.org/specialties/sports-medicine/sports-medicine-articles/elbow-injuries-in-young-throwers
  176. https://pmc.ncbi.nlm.nih.gov/articles/PMC12456395/
  177. https://pmc.ncbi.nlm.nih.gov/articles/PMC7930971/
  178. https://sportrxiv.org/index.php/server/preprint/view/400
  179. https://www.strongerbyscience.com/sex-differences-muscle-strength/
  180. https://pubmed.ncbi.nlm.nih.gov/3173042/
  181. https://pmc.ncbi.nlm.nih.gov/articles/PMC4756754/
  182. https://www.strengthlog.com/should-women-train-like-men/
  183. https://barbend.com/women-training-volume/
  184. https://pubmed.ncbi.nlm.nih.gov/35471634/
  185. https://helloclue.com/articles/cycle-a-z/how-your-menstrual-cycle-affects-strength-training
  186. https://journals.physiology.org/doi/10.1152/japplphysiol.00223.2025
  187. https://pubmed.ncbi.nlm.nih.gov/20086816/
  188. https://www.researchgate.net/profile/Randall-Jensen/publication/41088911_Strength_Training_for_Women_Debunking_Myths_That_Block_Opportunity/links/0fcfd505e13cb474af000000/Strength-Training-for-Women-Debunking-Myths-That-Block-Opportunity.pdf
  189. https://powerliftingindata.com/posts/2024/10/13/growth-by-gender-and-age.html
  190. https://www.sciencedirect.com/science/article/pii/S2666337625000162
  191. https://www.researchgate.net/publication/384406789_Beyond_the_Barbell_Women_in_Strength-Based_Sports_and_the_Reshaping_of_Gender_Norms
  192. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10485547/
  193. https://www.nia.nih.gov/news/how-can-strength-training-build-healthier-bodies-we-age
  194. https://pmc.ncbi.nlm.nih.gov/articles/PMC3117172/
  195. https://www.uclahealth.org/news/article/lifting-heavy-weights-may-be-beneficial-older-adults
  196. https://pubmed.ncbi.nlm.nih.gov/35968662/
  197. https://acsm.org/physical-activity-function-older-age/
  198. https://pmc.ncbi.nlm.nih.gov/articles/PMC11147802/
  199. https://pmc.ncbi.nlm.nih.gov/articles/PMC5161704/
Add your contribution
Related Hubs
User Avatar
No comments yet.