Squeamish warning: If you feel menstrual cycle chat is TMI, turn away now.
I went aGoogling "menstrual cycle athletic performance" today, after a ridiculous run this morning - it was supposed to be 5 miles at an easy pace, it was 2.5 miles at a near walk and 2.5 at a brisk stroll. I'm due to bleed today, and feel like crap warmed over. I've been a bit bitchy, yeah, but also just so tired but paradoxically unable to sleep. Yep. Sounds like a month in which one of my almost 47yo ovaries fired. That's rare lately, only about 25% of the time or less (and I root for less).
I've had the mood swing problem my whole menstruating life (and I am getting better at not blowing up like Vesuvius, even if I am still snarky), but not having been an athletic type I'd never had an issue with physical performance changing cyclically. Turns out, though, I'm not alone. Depending on what study you read, somewhere between 13% and 33% of athletic women (and one has to wonder how many of those polled even have periods) find significant drops in performance in the last week before and first few days of bleeding. One wonders whether they all throw in and take the Depo shots so they can be in whatever race they choose, rather than having to work around the calendar like I do.
This morning I was so peeved (although still not able to run far without a soaring heart rate, despite my ire) that I was thinking a full hysterectomy sounded like a great plan. But I doubt my insurance would cover it, and it'd probably backfire and cause me to lose some other hormone that's working for me.
Here's the best synopsis of research I found: http://www.thinkmuscle.com/articles/volk/planet-estrogen-03.htm
I also stumbled upon some really interesting stuff on digit ratio and predicted athletic performance, including some hard science. Google "digit ratio". Pretty cool: turns out your ring finger and index finger ratio is indicative of the amount of testosterone and other androgens you were exposed to in the womb. I appear to have been given the short shrift in my prenatal testosterone bath, which, I'm convinced, explains why I can't run a sub 20:00 5K.
So there. It's got nothing to do with training.