Lately, I’ve been practicing next to a significant number of injured women… and seemingly uninjured men. This gender discrepancy could be for many obvious reasons -- maybe there are simply more women practicing yoga (making the odds higher), maybe the injured women have been practicing for a longer time-period (thus more prone to overuse injuries), maybe women are naturally more flexible (and thus push themselves too far), or perhaps some men are injured but are masking their injuries.
After some research, I found that female rowers are injured more frequently than their male counterparts. This study looked at 398 rowers (42% female, 58% male) competing in the Junior World Rowing Championships in 2007, finding overall 73.8% reported overuse injuries, and 26.2% reported injury from a single traumatic event. Females had more injuries than males (110.2 vs 90.5 injuries per 100 rowers). (I'm still wondering if there was a gender difference in traumatic versus overuse injuries).
This is leaving me wondering -- is there something that makes women more prone to injuries from intense physical practices such as Ashtanga or rowing?
I’ve been thinking about the hormone progesterone. During pregnancy, the high levels of progesterone help the woman’s body gain flexibility in preparation for labor and delivery. Progesterone levels also rise in the last two weeks of the menstrual cycle (the “luteal” phase). Could this make women more “open” during this part of the menstrual cycle, and thus more susceptible to injury? (It could be coincidence, but this was the time when I pulled my serratus anterior back in December).
I was glad to see that this question has begun to be studied. Though a very small sample size (n=8), this study showed no difference in flexibility over the menstrual cycle. They divided the cycle phases into menstrual (estradiol and progesterone levels low), ovulatory (estradiol high and progesterone low), and luteal (progesterone elevated), and measured maximal isometric voluntary contraction, muscle activation level, and tendon properties (using ultrasound). They found no significant changes during the three phases.
I would love to see a prospective study of hundreds of Ashtanga practitioners (or a similar daily physical practice), that tracks type of injury along with menstrual cycle phase/progesterone level. In the meantime, I’ll continue with self-observation on this question.