Men and women have measurable physiological differences that influence strength, power, endurance, recovery, and injury risk. But how much should those differences actually affect the way we train?
A 2025 study led by Dr. William Kraemer and a new two-part position statement from the National Strength and Conditioning Association (NSCA), published in August 2026, provide valuable insight into this question. Together, these publications help explain how biological differences influence athletic performance, how men and women respond to training, and how certain considerations change throughout life.
The evidence suggests that the fundamental principles of training apply to both sexes. However, understanding differences in muscle development, strength, fatigue resistance, injury risk, and aging can help coaches make better programming decisions.
The Foundations of Training Are the Same
Progressive overload, specificity, recovery, and consistency drive training adaptations in both men and women. The NSCA's 2026 position statement reinforces that female athletes respond to strength and conditioning programs in many of the same ways as male athletes. Both can improve muscular strength, hypertrophy, power, speed, and endurance when exposed to appropriate training.
Research consistently demonstrates that men and women experience comparable relative improvements in many measures of strength and muscle growth. This distinction is important because absolute performance and relative improvement represent different outcomes. For example, a male athlete may lift considerably more weight than a female athlete, but both can experience similar percentage improvements following a training program.
This also challenges the misconception that women should generally train with lighter weights and higher repetitions. Both sexes benefit from appropriately challenging resistance training, and the intensity and repetition ranges should reflect the intended adaptation. Developing maximal strength requires sufficient exposure to heavy resistance, while building muscle can occur across a broader range of loads when training effort and volume are appropriate.
Female athletes should have the same opportunities to develop maximal strength, explosive power, and high-speed movement abilities as male athletes. The appropriate training stimulus depends on the athlete's goals, training history, physical capabilities, and sport demands.
Where Physiological Differences Matter
Although men and women respond similarly to many training methods, their physiological characteristics are not identical. On average, men possess greater absolute muscle mass, particularly in the upper body, contributing to higher absolute strength and power outputs. These differences become more pronounced following puberty, when hormonal changes influence muscle development and body composition.
Muscle hypertrophy, or the increase in muscle size, is one area where misconceptions are common. Testosterone contributes to the greater average muscle mass observed in men, but this does not mean women have a substantially reduced ability to develop muscle through resistance training. A 2025 systematic review and meta-analysis by Refalo and colleagues examined 29 studies comparing muscle growth between men and women completing the same resistance training interventions. The researchers found that absolute muscle growth slightly favored men, but relative increases in muscle size were similar between sexes.
This distinction matters when evaluating training progress. An athlete beginning with more muscle mass may gain a greater absolute amount of muscle, even when another athlete experiences a comparable percentage increase. Consequently, different starting points can create differences in total muscle growth without necessarily indicating a meaningful difference in responsiveness to training.
Strength development follows a similar pattern. While men generally demonstrate higher absolute strength, women can make substantial improvements through resistance training. A 2020 meta-analysis by Roberts and colleagues found similar hypertrophy and lower-body strength adaptations between sexes, with women demonstrating greater relative improvements in upper-body strength in the studies analyzed. These findings suggest that coaches should be careful when interpreting differences in training responses, particularly when comparing absolute changes with percentage improvements.
Another interesting consideration is fatigue resistance. Research suggests that women may demonstrate greater resistance to muscular fatigue during certain submaximal activities, particularly sustained or repeated isometric contractions. Differences in muscle fiber characteristics, muscle blood flow, and the absolute force produced during exercise may contribute to these observations. For example, women may sustain some lower-intensity muscular contractions longer than men working at the same relative intensity. However, these differences become less consistent during faster, more explosive movements and depend heavily on the exercise being performed.
This does not automatically mean women should complete more repetitions, tolerate greater training volume, or require less recovery between sets. Fatigue resistance is task-specific, and individual differences in training history, strength, exercise selection, and effort can outweigh average sex-related differences. Two athletes may respond very differently to the same percentage of their one-repetition maximum, regardless of sex. Monitoring movement velocity, perceived exertion, repetition quality, and recovery provides a more reliable foundation for determining appropriate training demands.
Training Differences Across the Lifespan
A 2025 study led by Dr. William Kraemer examined relationships between upper-body strength, lean mass, and bone mineral density across adulthood. The researchers evaluated 174 participants, including 105 women and 69 men, ranging in age from 19 to 84 years. Participants completed a maximal bench press strength assessment, while upper-body lean mass and arm bone mineral density were evaluated using dual-energy X-ray absorptiometry (DEXA).
The researchers found that increasing age was associated with lower upper-body strength and arm bone mineral density in both sexes. However, the relationship between age and upper-body strength was more strongly negative in men. Women demonstrated a trend toward a stronger negative relationship between age and arm bone mineral density, although this particular sex difference did not reach conventional statistical significance. Upper-body strength was also positively associated with arm bone mineral density, with a stronger relationship observed in women.
These findings provide an important perspective on musculoskeletal aging. Men may experience greater age-related differences in upper-body strength, while women face additional bone-health considerations, particularly during and after menopause. Declining estrogen levels during menopause can accelerate bone loss, increasing the importance of maintaining muscular strength and skeletal health.
It is important to recognize that Kraemer's study was observational. Because participants of different ages were evaluated rather than followed through a training intervention, the findings cannot establish individual rates of decline or prove that increasing strength directly prevents bone loss. The relationships identified nevertheless reinforce the importance of maintaining muscular strength throughout adulthood.
The NSCA's position statement also emphasizes that training priorities should evolve throughout development. During childhood and adolescence, both boys and girls benefit from developing fundamental movement skills, strength, coordination, speed, and power through appropriately designed programs. As athletes mature, training can become increasingly specific to their physical capabilities and competitive demands. During adulthood, maintaining and improving these qualities remains important, while later stages of life place greater emphasis on preserving muscle mass, strength, bone health, and independence.
Additional considerations, including pregnancy, postpartum recovery, and menopause, may influence training tolerance and program design for women. These circumstances require individualized adjustments based on health status, symptoms, previous training experience, and appropriate medical guidance. Across the lifespan, the overall objective remains consistent: develop and preserve the physical qualities that support performance, health, and long-term function.
Injury Risk and Training Considerations
The NSCA's 2026 position statement also identifies health and injury considerations that deserve particular attention when training female athletes. One example is anterior cruciate ligament (ACL) injury risk. Female athletes experience higher rates of ACL injury than male athletes in several comparable sports, including soccer and basketball. These differences are influenced by multiple factors involving anatomy, biomechanics, neuromuscular control, training exposure, and environmental conditions.
Strength and conditioning programs can address many modifiable contributors to injury risk. Progressive lower-body strength development, landing mechanics, deceleration training, plyometrics, and change-of-direction exercises can improve an athlete's ability to produce, absorb, and control forces encountered during competition. These qualities are important for both male and female athletes, although differences in injury patterns may justify additional attention to specific physical capabilities.
The NSCA also emphasizes the importance of monitoring low energy availability, bone stress injuries, and other health considerations that can affect female athletes. Low energy availability occurs when an athlete consumes insufficient energy to support both training demands and normal physiological function. When prolonged, it can negatively affect performance, recovery, hormonal function, and bone health. Although these problems can affect both sexes, certain consequences, including menstrual dysfunction, provide important warning signs in female athletes.
The goal is to identify relevant risks while continuing to develop the strength, speed, and physical capabilities required for athletic performance. Training should challenge athletes appropriately while accounting for their individual health and injury history.
What About the Menstrual Cycle?
The menstrual cycle is another consideration when training female athletes. Hormonal fluctuations and associated symptoms can influence perceived readiness, sleep quality, recovery, and training tolerance. However, the available research does not support universally prescribing different training intensities, exercise selections, or training phases according to the menstrual cycle.
Some athletes experience substantial symptoms that affect their training, while others experience little noticeable disruption. Tracking individual symptoms and performance responses can help identify patterns that warrant adjustments, but coaches should avoid assuming that every athlete responds similarly to hormonal fluctuations.
The NSCA emphasizes individual monitoring, and the practical recommendation is straightforward: Adjust training when symptoms, performance, or recovery indicate that an adjustment is needed. Consistent training and progressive overload remain the foundation, while menstrual health should be considered as part of the athlete's overall health and recovery.
What Should Coaches Actually Do Differently?
The clearest practical recommendation from the NSCA is to design training around the individual athlete and the demands of their sport. Sex-related differences can inform that process, but training age, current strength levels, injury history, technical proficiency, recovery capacity, and individual goals should guide exercise selection, intensity, volume, and progression.
For example, a female soccer player who demonstrates limited eccentric strength and difficulty controlling high-speed deceleration may benefit from additional lower-body strength and braking-focused exercises. A male baseball player with adequate maximal strength but lower levels of reactive strength may benefit from a different training emphasis. These decisions should be based on identifiable physical limitations and sport requirements rather than assumptions about what male or female athletes generally need.
Coaches should also recognize that training opportunities and previous exposure to structured strength and conditioning can influence performance. The NSCA's position statement highlights that female athletes have historically experienced unequal access to training resources, coaching, and development opportunities. Differences resulting from training history or access should not automatically be interpreted as biological limitations.
When evaluating an athlete, objective testing can provide valuable information about current capabilities and areas for improvement. Strength assessments, jump testing, movement analysis, and other performance measures can help identify appropriate training priorities. Monitoring how the athlete responds over time allows those priorities to be adjusted as physical capabilities develop.
Ultimately, effective programming requires understanding the athlete's current abilities, identifying the physical qualities that matter most, and applying an appropriate training stimulus.
The Bottom Line
Men and women share the same fundamental capacity to adapt to appropriately designed training. Both can develop substantial strength, muscle mass, power, speed, and endurance, and both benefit from consistent exposure to progressive training.
Biological differences matter, particularly when considering absolute strength, muscle growth, fatigue characteristics, injury risk, reproductive health, and aging. However, these differences rarely justify entirely separate training philosophies. Coaches should use the research to understand potential considerations while allowing individual performance and training responses to guide their decisions.
At Newman HP, we believe effective training begins with the demands of the sport and the needs of the individual. Understanding the science helps establish the framework, while evaluating the athlete determines how that framework should be applied.
About The Author
Ben Kaiserman is a Senior Partner at Newman HP, where he works with professional and collegiate athletes across the MLB, NFL, PLL, NCAA, and professional lacrosse. Prior to joining Newman HP, he served as an H2F Strength and Conditioning Coach with the U.S. Army's 101st Airborne Division, working with tactical athletes in a high-performance military setting. He holds a Master's in Sports Administration from Tusculum University and is a Certified Strength and Conditioning Specialist through the NSCA. He previously served as Director of Sports Performance at Tusculum University and has also worked with athletes at UCLA, Yale, the University of Tennessee, and Sacramento State.
Frequently Asked Questions (FAQ)
Should women lift lighter weights and perform more repetitions than men?
No. Both men and women benefit from resistance training across a variety of intensities and repetition ranges. Training should reflect the intended goal, whether developing maximal strength, muscle size, power, or muscular endurance. Women can benefit from heavy resistance training just as men do, provided loading is appropriate for their strength, experience, and technical ability.
Do men build muscle faster than women?
Men generally have greater absolute muscle mass and may gain slightly more muscle in absolute terms. However, research suggests that relative muscle growth, measured as a percentage increase from baseline, is similar between men and women following resistance training. Individual training experience, nutrition, recovery, and program design also influence results.
Do women recover faster from workouts than men?
Women demonstrate greater fatigue resistance during certain muscular tasks, but this does not necessarily mean they recover faster from every type of workout. Recovery depends on the intensity, volume, exercise selection, training history, and individual athlete. Coaches should monitor performance and recovery rather than automatically prescribing shorter rest periods or greater training volumes based on sex.
Should women change their workouts based on their menstrual cycle?
Current research does not support a universal approach to menstrual cycle-based training. Some athletes experience symptoms that meaningfully affect performance or recovery, while others do not. Training adjustments should reflect individual symptoms, readiness, and performance rather than predetermined assumptions about specific cycle phases.
Do boys and girls need different strength training programs?
During childhood, boys and girls respond similarly to many forms of strength and conditioning. Both benefit from age-appropriate resistance training, movement development, coordination, speed, and power exercises. As athletes mature, physiological differences become more pronounced, but programming should continue to prioritize individual development, physical capabilities, and sport demands.
How should training change as men and women get older?
Both sexes benefit from maintaining muscular strength, muscle mass, power, and overall physical function throughout adulthood. Older adults may require additional attention to recovery, exercise progression, and bone health. Women face particular bone-health considerations associated with menopause, but resistance training remains an important component of healthy aging for both sexes.
References
Kraemer, W. J., Chaudhry, N. F., Graham, J. H., Stauder, M. J., Onate, J. A., Fragala, M. S., Volek, J. S., & Hayes, S. M. (2025). Sex differences in upper-body strength, lean mass, and bone density across the adult lifespan: Insights into musculoskeletal aging and strength preservation. Journal of Applied Physiology, 139(4), 1000–1009. https://doi.org/10.1152/japplphysiol.00544.2025
Dabbs, N. C., Binkley, H., Bott, C., Fragala, M. S., Herda, A., Moeskops, S., Moore, E. W. G., Smith-Ryan, A., & Triplett, N. T. (2026). National Strength and Conditioning Association position statement on strength and conditioning of female athletes. Part I: Lifespan, injury, and health considerations. Journal of Strength and Conditioning Research, 40(8), 875–894. https://doi.org/10.1519/JSC.0000000000005544
Dabbs, N. C., Binkley, H., Bott, C., Fragala, M. S., Herda, A., Moeskops, S., Moore, E. W. G., Smith-Ryan, A., & Triplett, N. T. (2026). National Strength and Conditioning Association position statement on strength and conditioning of female athletes. Part II: Training adaptations and program design. Journal of Strength and Conditioning Research, 40(8), 895–908. https://doi.org/10.1519/JSC.0000000000005493
Refalo, M. C., Nuckols, G., Galpin, A. J., Gallagher, I. J., Hamilton, D. L., & Fyfe, J. J. (2025). Sex differences in absolute and relative changes in muscle size following resistance training in healthy adults: A systematic review with Bayesian meta-analysis. PeerJ, 13, e19042. https://doi.org/10.7717/peerj.19042
Roberts, B. M., Nuckols, G., & Krieger, J. W. (2020). Sex differences in resistance training: A systematic review and meta-analysis. Journal of Strength and Conditioning Research, 34(5), 1448–1460. https://doi.org/10.1519/JSC.0000000000003521
Hunter, S. K., & Senefeld, J. W. (2024). Sex differences in human performance. The Journal of Physiology, 602(17), 4129–4156. https://doi.org/10.1113/JP284198
