The Effects of Weight Training on Women
- Mar 30
- 4 min read
There's a phrase women still hear frequently in the fitness world:
"If I train with weights, I'll get very muscular."
It's no coincidence that elite sports have separate categories for men and women; biologically, men have a distinct advantage in strength, speed, and endurance thanks to their greater average muscle mass, higher hemoglobin levels, and larger bone structure. At the heart of this difference lies testosterone. A large summary study by Handelsman et al. (2018) shows that performance differences in adults can be largely explained by circulating testosterone levels .
This data also helps us understand that it is biologically highly improbable for a woman with normal hormone levels to "accidentally become muscular and look like a man" simply by weight training.
Female and Male Testosterone: The Numerical Facts
Handelsman 2018, using the reliable measurement method LC-MS to analyze large series, provides the following reference ranges:
Healthy young men: 7.7 – 29.4 nmol/L
Healthy premenopausal women: 0 – 1.7 nmol/L
Well:
Men's testosterone levels are approximately 15–20 times higher than women's .
The distributions hardly overlap : the testosterone range for "normal men" and "normal women" is distinctly separated.
Even when mild hyperandrogenic conditions such as polycystic ovary syndrome (PCOS) are taken into account, a reasonable upper limit of 5 nmol/L is recommended for women; levels above this are generally considered to be associated with conditions such as tumors, DSD, doping, etc.
This means that a normal woman's hormone profile is structurally well below the range that would allow her to develop "male-type muscle mass." Weight training doesn't change this biological fact; it simply optimizes the body within this range .
