"When Oda was young (about 10 years ago), he usually slept only for 2 hours a day. It does not mean that he slept for 2 hours straight. It was an accumulation of 15 minutes' sleep...
Besides, he was on the verge of getting a slipped disc about 6 years ago.
Although he has various kinds of pastime (video game, concert etc), I am worried that Oda is totally exhausted. He said before, "it is the worst betrayal to readers if I can't draw manga any longer losing health." I hope Shueisha will give him a break at least twice a month. And I hope Oda will stop smoking and eating too many doughnuts. He eats about 50 doughnuts every week..."
Dat ruinage de santé 