This is a common misconception, says Prof Leigh Breen, a muscle physiology specialist at the University of Leicester, though it’s easy to see where it comes from. Men typically have a higher ratio of muscle to fat than women, largely because of differences established during puberty, when testosterone levels rise significantly in males. Women, by contrast, tend to have a higher proportion of body fat – linked, in part, to oestrogen.
“Although there is a relationship between testosterone and the amount of muscle mass we have, this doesn’t determine how effectively we can build muscle with resistance training,” says Breen. “Women have much lower testosterone levels – around 15 to 20 times lower than men. There is a perception that men gain muscle more easily because of higher testosterone and more androgen receptors in muscle, but that’s not quite right. If you look at relative change – the percentage increase – men and women respond very similarly to training.”
double quotation markFor women, pushing body fat very low usually requires quite extreme diets and training
That means most people don’t need gender-specific workouts to build muscle. “There are physiological differences to consider,” he adds, “but broadly speaking, men and women can follow the same resistance training principles and expect comparable progress, particularly when they’re younger.”
Body composition is a different question. Even with training, women are likely to maintain a higher fat-to-muscle ratio than men. “You can shift that balance,” he says, “but pushing body fat very low usually requires quite extreme diets and training.”
At those extremes, there can be trade-offs: “Very low body fat in women is associated with hormonal disruption, irregular menstrual cycles and potential impacts on fertility.” So it’s possible to change those ratios, but it’s not always desirable from a health perspective.
