[p47]

Well you all may missing the point. It's not important at what hour You get up. The matter is how long did You sleep. Normal person needs up to 4 circadian cycles. We make one every 1.5h, it varies individually. Here is real catch, if You sleep over this four cycles. Your brain starts to use some proteins produced during sleep. Its big waste because catecholamine is produced only during sleep. So if You over sleep, You loose energy, and You may wake up tired.

To start wake up earlier, this was tested by myself. You need to reset your brain. So don't sleep for night or two. And after go sleep on proper time. For 6-6.5h. You will be fresh as new born.

Interesting about the sleeps starts when You have idea about, training polyphasic sleep :-). Well its different story.