Vincent Chen, B.S
When talking about resistance exercise, some people believe that women respond less than men in terms of muscle mass and strength gain, while others think that it may make women look bulky. Many women therefore tend to avoid doing resistance exercise. However, the benefits outweigh the possible drawback of bulkier appearance. Physical inactivity-induced muscle loss may reduce an individual's ability to resist impact and lower the basal metabolic rate (BMR) to an unhealthy level. Furthermore, women start to lose a large amount of bone mineral mass after menopause, a trend that is able to be countered by resistance exercise, which has been proven to be beneficial for improving muscle health and bone mineral density. Thus, regular resistance exercise offers significant benefits for women.
Is it true that women respond less to resistance exercise than men? Many people observe a higher absolute muscle gain with resistance exercise in men than women, and believe it is due to higher levels of naturally-occurring testosterone in men. A study conducted in our laboratory (Human Countermeasures Laboratory at Texas A&M University) showed that 201 men and women gained the same percentage of muscle mass and strength after performing a 12-week progressive resistance exercise training program. That is, we found that women and men respond similarly to resistance training.
The difference in body composition between men and women appears to be the main reason why women gain less muscle, in absolute terms, than men do with resistance training. In general, men have a larger portion of muscle in their bodies than women, while women have more fat than men. The average body fat for healthy adult individuals is 15-18% in men and 22-25% in women. The amount of muscle gain, in terms of increase in pounds or kilograms, depends on the original amount of muscle mass before training. Women simply start with less muscle mass. In fact, as our study suggested, women may gain as much muscle mass as men if they start with the same amount of muscle mass. For example, when a man with 130 lb. and a woman with 90 lb. of muscle mass both increase 10% of muscle with resistance exercise, the absolute amount of gained muscle mass would be 13 pounds in the man and 9 pounds in the woman.
Some women avoid resistance exercise for fear of “bulking up” and developing an unattractive physique. However, since women have a smaller portion of muscle mass than men, resistance training will not make their absolute amount of muscle mass increase as much as it does in men. Female weightlifters who want to pursue the bodybuilder physiques perform massive amounts of resistance exercise. Moderate resistance exercise evokes loss of body fat while maintaining muscle mass and developing muscle tone, but not bulky muscle growth.
In summary, resistance exercise not only increases muscle mass and strength, but also brings many health benefits such as developing higher basal metabolic rate and bone mineral density. Muscle mass gain with resistance training depends more on the original amount of muscle mass than on gender. Moderate resistance exercise makes women look fit and toned but not bulky. Therefore, yes, women should definitely do resistance exercise to get lean and toned, and build stronger bones!
Vincent Chen, Chang Woock Lee, Teak Lee, Gentle Chikani and Steven Riechman. Lean Mass Gain with Resistance Training Is Independent of Gender. FASEB Journal. 2009; 23 (1): 955.26. http://www.fasebj.org/cgi/content/meeting_abstract/23/1_MeetingAbstracts/955.26
Asikainen TM, Kukkonen-Harjula K, Miilunpalo S. Exercise for health for early postmenopausal women: a systematic review of randomized controlled trials. Sports Med. 2004;34(11):753-78. http://www.ncbi.nlm.nih.gov/pubmed/15456348