Quote Originally Posted by Dianyla View Post
I've always read that about 15% body fat is required to support regular ovulation/menstruation.
Medically speaking, below 15% body fat you start to worry about someone, but they still could be quite healthy. Below 9% is very dangerous. That's where the 2 different figures come into play.

And yes, the effects on bone density are serious so you need to figure it out.

As for base mileage versus race mileage, in the base period your volume goes up but the intensity is lower. During the race period, intensity is up so you need more rests between intense efforts and therefore the overall mileage drops. During my base period I will train around 20 hours a week. During my racing period it's more like 12.