your not going to lose muscle in 10 days. from what i've read, your body loses what needs to be lost (toxins, fat, etc...). and you'll be pleasantly surprised after your 10 days! after my first in feb (2 days into my 2nd now) i really began to care about what i put in my body and didn't gain a single pound back...even kept losing a bit. read this post below. it tells what kind of maintenance i did after my 10 days. you can totally do this in a healthy way! hell, if i can do it, ANYBODY can!