That has nothin to do with energy, it has to do with their heart rate dropping at rest and causing heart attacks.lance armstrong and all the tour de france bikers. they're pumped with so much EPO, even after riding 100 miles per day, they still have to take their bikes out at night to burn all that energy off. then they'll ride another 100 miles next day... and so on...
They are trying to get the blood flowing again as it stops when they are resting, thats life and death shit, not too much energy
The Science of Sport: Cyclist dies in sleep