4. Estrogen shifts metabolism to a greater reliance on fat and less on carbohydrate when running at the same pace as a man. The longer the race, the more important this shift in metabolism becomes, since the conservation of carbohydrate is very important given that we have only a limited store of it. The faster the pace you can run while still using mostly fat, the better long-distance runner you will be. Most women, therefore, get better the longer the race. The performance difference between men and women is much smaller for ultramarathons than it is for races shorter than a marathon because the longer the race, fuel use starts to outweigh the importance of cardiac performance and oxygen transport in the blood, characteristics that favor men. Because of women’s estrogen-induced predisposition toward endurance, women should embrace aerobic training and run a lot to maximize their running performance. (Get my book, Running for Women, for a lot more detail, including how to train around the menstrual cycle, pregnancy, and menopause.)
....Stay tuned for more tips!