Watched the 60 minutes clip of Shalane Flanagan posted on the homepage.
5 ft 4 in and 102 pounds. That's a BMI of 17.5, 18.5 is the cut-off for being "under nourished".
Do marathoners have genetic abilities to weigh so little and still have functioning estrogen-producing ovaries? Or is Shalane using other tricks to keep training without breaking her bones while being amenorrheic?
There are a lot of distance runners with really low running weights listed on their pro pages who have been able to go through one or more pregnancies. Are they actually able to keep menstruating while they weigh so little or do they gain 20+lbs to get pregnant?
In my years of competitive running, whenever my teammates had their BMI drop below 19 they would stop menstruating and after a season of that they would develop osteopenia. How little these women weigh blows my mind more than any other aspect of their training.