Men and women both have incredible potential when it comes to increasing their strength, hypertrophy, and power with resistance training. Over the last few decades, multiple studies have explored potential differences playing roles in how the sexes adapt to certain forms of resistance training.
In a recent meta analysis, authors looked at multiple studies that compared men and women and how they respond to resistance training from both a strength and hypertrophy point of view. (1)
This was a really cool read and provided a lot food for thought when it comes to programming for the sexes. It’s well understood that differences like hormone levels, lean body mass, and total muscle mass exist between the sexes, but how do these influence training responses exactly?
Suggestions From the Meta-Analysis
In the meta-analysis, authors looked at and compared three key areas of performance and these include: hypertrophy, upper body strength, and lower body strength. It’s worth noting that a majority of the research included in this meta-analysis was on untrained individuals and resistance training variables varied slightly between the different studies.
When it came to hypertrophy, the authors looked at 10 different studies that met their criteria and suggested that hypertrophy adaptations were similar between the sexes within the research they looked at.
In regard to lower body strength, 23 studies were considered and like hypertrophy, both sexes responded similarly in regard to overall gains based on the strength markers used in the research. Despite lower body strength gains being similar, upper body strength varied to a greater degree within the 17 included studies and larger increases were observed for women.
Factors Worth Considering
To date, research has been light in respect to comparing the sexes and some of the deeper physiological differences that could be at play in regard to how men and women respond to different forms of resistance training.
Related: Why women may do better with RPE training compared to men!
The results above are interesting, however, it’s worth remembering that a large amount of the study populations assessed were untrained. Accounting for this could suggest why untrained women saw greater increases in upper body strength. If this form of training was a novel stimulus and there was no prior exposure to upper body strength training whatsoever whether it be through work, sport, or lifestyle, then it makes sense that their upper bodies responded more rapidly than men.
In the discussion section of the meta-analysis, authors pointed out a lot of interesting considerations that should be accounted for when programming for different sexes. I highly suggest checking out the meta-analysis (linked above) if you have time.
Neuromuscular Considerations
In the meta-analysis, authors point out little is still known about potential neuromuscular differences that could be at play between how the different sexes adapt to various forms of training.
However, it is suggested that men have the potential to fatigue faster from heavy training compared to women, but the exact reasoning why is still unclear. (2) Additionally, men generally have a larger ceiling of fitness than women, which could explain why women adapt more rapidly to certain forms of novel stimuli (newbie gains).
Muscle Mass and Hormonal Considerations
Between the sexes, men generally have higher lean body mass and total muscle mass compared to women, while women have higher percentages of body fat. Outside of these differences, authors point out that one explanation between the discrepancies in how the sexes respond to different forms of training could be due to difference’s in each sex’s muscle phenotype.
Essentially, varied responses to resistance training could be due to how muscle fiber composition varies between sexes. Despite some studies suggesting that women have higher percentages of Type I fibers in the vastus lateralis and biceps brachii, which could be information used to suggest best training practices, research is still thin on this topic to draw any conclusions.
When it comes to hormonal differences, men generally have higher androgen levels than women, which could suggest why women experience less change in muscle size with hypertrophy-oriented training. Authors also point out that while men generally see greater increases in absolute hypertrophy and strength than women, relative increase between the sexes are similar over time.
Another hormonal factor that was discussed are the differences women may experience during their menstrual cycle. Research is still relatively light on the exact mechanisms that could be at play in regard to strength and hypertrophy adaptations during various parts of the cycle, but there are some suggestions as to where growth and fatigue occur most.
Authors also referenced that when it comes to muscular fatigue, sex differences depend on the task being performed. However, it’s been suggested that women experience fatigue less muscular fatigue when performing isolated contractions.
The Takeaways
There are multiple differences that exist between the sexes, and their intricacies need more research to fully understand how they adapt to certain forms of resistance training. Men and women both have incredible potential to grow with resistance training.
Hopefully as time passes, we continue to understand the exact mechanisms at play causing growth in various settings.
References
1. Roberts, B., Nuckols, G., & Krieger, J. (2020). Sex Differences in Resistance Training. Journal Of Strength And Conditioning Research, 34(5), 1448-1460.
2. K, H. (2020). Neuromuscular fatigue and recovery in male and female athletes during heavy resistance exercise. – PubMed – NCBI.
Feature image from Microgen / Shutterstock
