In fact, some women — more than 1 in 3 — have inner clocks that run especially fast. They complete a daily cycle in less than 24 hours.
"If your cycle length is shorter than 24 hours, you need evening light to keep you synchronized," Duffy says. And such people should get blackout shades for the bedroom so morning light is as dim as possible.
http://www.npr.org/2011/05/03/135954176/womens-circadian-rhythm-beats-faster-than-mens
Для меня кое-что проясняется