That is not to say that I forbid my men-friends to read it (I would never shun 50% of my readership!), just that you won’t really care.  And I welcome any of my men-friend runners to do a guest post on nipple chafing or supportive briefs.  Really.

But I’ll stick to what I know.

It’s day 3 of my half-marathon training, and I am mentally going strong.  But I noticed this morning on my “ass-crack-of-dawn” run that I was unbelievably winded.  I had been equally winded my previous run at the same trail (Monday) but since it was very warm, I attributed it to the heat.  This morning however, with the beautiful 67 degree temps, this was not quite right.  And then it hit me: I’ve had my period since Monday, and I bet that is contributing to my difficult runs.

I have suspected this before, and now that I am actually training for something that will be a strong challenge to my body, I decided it was time for research. More specifically, I want to see if there s supposed to be a pattern to the days where I feel I can run forever and the days that I feel I can’t bare run another step, and if it is predictable. Not surprisingly, it seems there is.

I found a  few great articles  (this one too) on this topic (please click on the links if you want to read them), but I want to point out that I think it’s very likely that every woman is going to have a different experience.  For example, I have been on the very same birth control for 12 years, so I have my menstrual cycle down to an easy-breezy science.  I know when I am getting it, I know that I will be mildly tired on the Wednesday of that week and I know that it will end Sunday night. I know I will not have bad cramps or spot bleeding after. (Men, stop making that face.  I told you this was for the ladies.)  For this reason, tracking will be easy for me. This month I will note every run I do and how I felt and then will pretty much know what my “cycles” are.  For other women, it probably changes every time, and you will need to track for at least 3-4 months to be able to predict.

Here’s what I think I’ve learned. During the parts of your cycle when you have low amounts of estrogen in your body (apx. days 3-15, day 1 being the day you get your period) you can expect high intensity runs (for example, Speed work and Hills) to have plenty of easy sources of fuel from your body, and you should have no problem with getting the burst of energy that you need to do so. After day 15, when you have higher levels of estrogen in your body, it’s not so easy. Your body changes its metabolism (where it favors metabolizing fat to muscle glycogen), and while you should have longer term sources of energy (so, a long slow run will go splendidly), you may not have the bursts of energy you may want for speed or higher intensity runs (muscle glycogen) readily available. Now that I have this knowledge, I have an idea. Clif bloks if needed. And now that I have put this all together, I feel armed to try to take on my period a little smarter. Or not. I mean, after all, I got all of this info from the INTERNET. Really, I won’t know anything until I try it out.  It could be bologna. Or maybe it’ll just be the mental kick in the ass I need.

Please note: I am not a doctor, nurse or anyone who knows anything about anything.  I am just reporting what I have noticed in myself and read in online sources.  Really I would love for other women to post their experiences.   So, other women runners, have you paid attention to your cycles? Have you noticed anything? Have any suggestions?