Today's run + TMI?

This post may contain too much information for male readers, unless you can read the word 'period' without getting a little anxious; if that is you, that's cool, read another day - if it isn't, feel free to read on.

Back in the summer when I tried running for the first time, I noticed that some days I was full of energy and could just blow out my run in no time, and others I was just exhausted and couldn't even make it a third of the way without stopping. At first I thought this could be attributed to sleep, or not eating right the day before certain runs, or any of a million other causes. After talking to a friend of mine who is in sports medicine and nutrition, the issue was cleared up. I seems that many women (though not all) can experience a dip in energy levels in the week leading up to their period, and even a bit during. This week, I am feeling that pain. I went for my usual lunch time run this afternoon and felt like death the whole way through. I managed to finish, but that was about the only good thing about the experience. For those of you who think they might be experiencing the same thing, here is a bit of the science behind it, as explained by my friend:

"If you can't chalk it up to hydration or how much glycogen is in your muscles, FYI it's medically proven women are weaker during the luteal phase of their menstrual cycle. Glycogen is the stored form of glucose in a muscle cell. Exercise uses up glycogen. And the luteal phase of the menstrual cycle is the week before your period, PMS time."

I guess next step is to find out how to combat that, or to take it in stride and accept that I'll just be a bit slower one run or two out of a month.