@jun_za I'd say if he's waking up that easily, then he should work out more add some cardio etc... I have trouble falling and staying asleep. When I have a long day at work and I do a workout after I sleep like the dead.
@lmr No, there's a small % of the population who go sleep at 10pm and wake up at 4am and sleep all the way through and feel well rested. They feel and function exactly the same as someone who went to bed at 10pm and woke up at 6am.