Ok.Alex,Many thanks!Now,I decide to sleep 5 hours every night.
Even if I sleep 6 hours per day.Every classmates thinks that I'm crazy.They all think that a man should get a 8 hours sleep.In china,some successful people work hard but with heavy stress,many of them died when they are youth.But still many people can sleep less and get a healthy body.
Another question.Since you have explored in QiGong.You may know that during 11:00~1:00 in night,It's the best time to sleep.Why you choose sleep from 4 a.m. to 8?In our traditional option.A man should go to bed before 3:00 at least