I was talking to my dad on what he thought about polyphasic sleeping and he said that it doesnt sound like an good idea. Now there are possibly some benefits from this like more time but it really doesnt make sense. When going poly your body doesnt get the rest that it needs. Poly gives it a false feeling of rest. Adults need about 8 hours of sleep a day to live a healthy life. Im not saying tests have been done on people doing poly and they are fine, im talking about long term. I was also thinking since your poly it could be the reason you couldnt build the 15 pounds of muscle you wanted. Less sleep equals more fat. If you are consistantly getting less sleep and still working out then your just fighting an uphill battle.
I have been doing some research on this because I thought it was interesting. But im into a healthy living and this doesnt seem to be my cup of tea. People wanting to try poly don't let me hinder your thoughts on doing it.
Hey also read this: http://www.tech-recipes.com/blog202.php
Thats where I got a little of my info.