Do Men and Women Respond The Same To Weight Training?
Do Men and Women Respond The Same To Weight Training?
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Do men and women respond the same to weight training?
Human muscle tissue is pretty much made from the same stuff whether you’re a man or a woman. Compared with men, generally women possess significantly less muscle mass, more body fat, and smaller muscle fibres [1]. However, the question, do men and women’s muscles respond the same to intense weight training, is one that I’m asked often. Particularly by women that are fearful of building “too much muscle” from training with weights. In light of some recent research, I thought I’d provide readers of this website with the most up to date information.
Previous research on the topic of sex-specific responses to weight training suggest that there maybe some differences between men and women. One of these differences is a more rapid myosin heavy chain isoform transition in women, another is minor variations in structural damage/inflammatory responses [2]. However, all the previous research available suggested that these differences did not contribute to any sex-specific adaptive responses to weight training [1,3,4]. That is, all previous studies suggest that men and women show no difference in their capacity for gaining muscle mass. Now that doesn’t seem exactly right does it? I mean, unless you live in Los Angeles, it’s pretty clear to most people that women don’t pack-on muscle mass the way men generally do. One recently published study [5] has shed some light on this rather confusing subject.
Unlike most other weight training studies, this new study utilized a large cohort (342 women, 243 men), and it revealed some clear gender-specific differences in strength and muscle growth (hypertrophy) development. In this study the men and women were all placed on the same 12 week high-overload weight training program. Unlike a lot of weight training studies, this one was specifically concerned with the hypertrophy response to training. The cross-sectional area of the upper arm muscles (biceps and triceps) of these previously untrained men and women were examined before and after the training program. The results showed a 2% difference between men (20%) and women (18%) in hypertrophy. Now you’re probably thinking that 2% doesn’t mean a whole lot, but in a study of nearly 600 people, that difference was considered to be highly significant (P < 0.001).
Now, a key point is that all the previous short term studies on this topic reported sex-specific differences in hypertrophy development that were as high as 6-7%. However, due to the smaller number of participants in these studies, the differences were deemed not statistically significant. Therefore, based on this new research, it appears that there are gender differences in the rate and capacity at which men and women can build muscle, it’s just that these differences may have gone undetected previously due to a lack of statistical power. Men generally build more muscle as a faster rate; whereas women tend to show a greater change in strength.
An interesting finding from this new study was that after 12 weeks of training, the women outpaced the men considerably in relative gains in strength. This may be due to a female’s lower initial starting strength level. That means gals can get some great increases in strength from training, without the large increase in muscle mass. Also, this research confirmed that there are large individual variations in the hypertrophy response that is evident in both men and women [5]. Remember that this research only lasted 12 weeks; so what happens during prolonged training?
The reality is that no long-term studies have examined sex-specific adaptive responses to RE. However, if we look to cross-sectional data on male and female bodybuilders [6] combined with the results of longer term (6 month) training studies on females [7,8], its pretty clear that the hypertrophy response to prolonged training is of much less magnitude in females than that observed in males. Scientists are still not sure exactly why men build more muscle and strength than women. However, it is most likely to be partly due to apparent differences in resting and acute anabolic hormonal responses to training [9,10]. For example, circulating testosterone concentrations are generally 10 times higher in males than in females [11]. The bottom line is that science shows that there is a difference between the sexes with regard to the rate and magnitude each can build muscle. The amount of muscle women can gain in response to weight training is small but significant. Muscle only serves to improve body shape, promote better fat and carbohydrate metabolism. For men and women, the most effective weight training program is Max-OT.
