dunno about boxing, but I knew some lads who'd have a two hour nap in the middle of the day.I know little enough about this shit, but 7 hours sleep seems WAY too little for intensely training like this. Smells more like legend-building than an accurate description to me
Their routine was something like: on the bike -> warm down / wash / stretch -> nap -> lighter cardio / recovery -> bed for the night.
But the nap would be a solid two hour + break in the middle of the day, and they felt that it allowed you to recover better. Then they didn't need to worry about getting the full 8 hours at night or whatever.