Estrogen is the main female sex hormone, equivalent to testosterone in men. In the world of exercise, testosterone gets a lot of good PR. Both male and female athletes sometimes cheat by taking synthetic testosterone (steroids) to gain an edge in their sport. While testosterone is widely regarded as a performance booster, what does estrogen do?
In females, estrogen regulates things like the menstrual cycle, weight gain/weight loss, and bone formation. However, its role in athletics seems to have been downplayed. According to a study published in Frontiers in Physiology, estrogen helps build muscle mass and improve strength. It can also make connective tissues stronger.
In women, estrogen seems to play a similar role as it does in men. Testosterone is known as an “anabolic” hormone in men. Anabolic means that it helps build tissues, such as muscle mass. Estrogen seems to do the same for women.
However, the study also points out that estrogen can make tendons and ligaments more flexible. This can be bad news for women who have high estrogen because it makes them more prone to injury. For example, ACL tears are more common in women than men. The ACL is a ligament that connects the femur (thigh bone) to the tibia (shin bone).
If high estrogen causes ligaments to soften and become more pliable, it could explain why women are more susceptible to ACL tears than men. It might seem odd that estrogen would weaken tendons and ligaments, but scientists propose a hypothetical reason that involves childbirth. As a baby passes through the birth canal, the hip bones need to widen. It’s much easier for them to move if ligaments are lax.
In addition to boosting bone formation, estrogen helps build muscle and strength. This comes at a cost of loose ligaments and tendons. While the researchers don’t propose a solution to this problem, it’s important to point out that estrogen can, in some ways, be considered a performance enhancer for women who lift weights.