I'm a firm believer in LISTEN TO YOUR BODY. I train 6 days a week, I eat constantly, every 2 hours, even if it's only an orange and a cup of yogurt. I sleep 4-5 hours most days and up to 8 if I'm really tired. I have made nothing but progress in the gym over the past year. I think diet is more important than sleep. If you're well rested, but have no fuel you're not going to build any muscle. What's worse is that if you're not well fed your body will scavenge your fat AND muscles stores looking for the energy and the protein it needs.