its not the only time. they grow better when you sleep, but they grow when you just rest too. its the same as with you're height. you grow a bit all the time, but its so little you dont notice it until some time has passed.
if muscle growth only happenes at night, why bother eating any protein during the day?
hmm ever hear about HGH? Growth Hormone (HGH) Elevates during deep sleep, Not when one is awake. And when HGH levels raise so does IGF-I. and IGF-I is key player in muscle growth.
well when i wake up after 6-8 hours of sleep, i feel really sleepy but after 1 minute of being awake, i feel awake and i can get my day going. i eat breakfast right away and i feel good. but when i get home at 3:10, sometimes i feel tired and at school too sometimes i feel like sleeping (prolly kuz its just sitting and listening to blah blah blah).