Why you won’t become “too muscly” if you lift weights as a woman
There’s a number of hormones in your body responsible for the growth and repair of your muscle.
Growth Hormone, Growth factors and even insulin play an important role in regulating cells called satellite cells that surround the muscle fibres (like the way a satellite orbits the earth). When the muscle is damaged, these move in to replace the lost muscle fibres.
However what defines the actual size of the muscle is the ratio of protein synthesis to muscular breakdown.
The most fundamental difference in the hormonal make up of men and women is testosterone and oestrogen.
Testosterone is responsible for promoting protein synthesis. It does this by altering the DNA of the muscle cells to produce more proteins (using the broken-down proteins, that you’ve eaten as a resource to build the new proteins). For this reason we call it a steroid hormone, meaning it effects your DNA.
Women have around 16 times less testosterone produced in their body than men, hence why the actual size of the muscles is significantly smaller.
When men are said to take “steroids”, what they are usually taking is testosterone which enhance this effect.
Sam Fitzpatrick Final Year Medical Student, Cardiff University.
Milad Rouf Final Year Medical Student, Cardiff University.
Charge, S. B. P., and Rudnicki, M.A. (2004). Cellular and molecular regulation of muscle regeneration. Physiological Reviews, Volume 84, 209-238.
Research Article reading [Accessed: 02/09/2017]