performance lessening during PMS and menstruation

[shootingstar]

Why don't you decrease your focus on performance and just try to enjoy the ride when you are having PMS symptoms? If you slow down, this might increase the "good feeling," and decrease the physical symptoms. Stress about performance would definitely add to PMS symptoms, even physical ones, which I was the queen of. You certainly don't need to be "fast" when you commute. Riding at a slower pace will still get you the positive benefits and you won't have to "take the car" (though there is nothing wrong with that, either).
It sounds like you might benefit from some relaxation/stress reduction strategies, like yoga or meditation. Have you done any other type of therapy to deal with your athletic amenorrhea disorder? My experience has been that sometimes people tend to substitute one type of thing they can "control" for another, unless the root cause of your need to do this is worked on.

Like the others here, Kate: ask yourself why you need to always maintain the level of cycling performance that you ask of yourself. Are you training to compete? Are you riding to keep pace with a much stronger rider(s)? That would be a different matter. Enjoy the ride, particularily on days when you aren't feeling optimum because of menstrual cramps, etc.

How long have you been cycling regularily?
I've been doing the same distance daily as you have. I'm short and small-boned. My BMI is 18%. Don't really care about my body fat measurement and my doctor as of 2 wks. ago, didn't care either. I'm abit under 95 lbs. Though I've been eating more, have lost 5-6 lbs. in past few months because of all this regular cycling. Most likely weight will be regained over the winter. It's an ongoing cycle nearly yearly. Over the past few decades, I have occasionally lost my period, but I always regained it back after 1-2 months. I never needed a physician to advise on this occasional problem nor take estrogen nor birth control pill to regularize menstrual cycles.

But every woman is different. My iron is back to normal. Not sure if it's due to same as your athletic amenorrhea, but I did not need to take estrogen.

I am in perimenopause...incredibly rare, short flashes, just a slow fade out over past 2 yrs. Never really experienced menstrual cramps in past nor now. Given my history, am probably very lucky. And due to reasonable (not perfectly) healthy eating and enjoying regular cycling for quite a number of years!!

Relax, Kate. You're in great shape, no matter what others may think. Unless you want to be another Jeannie Longo.

It's a beautiful autumn. Enjoy it. Focus on that now.