I am 20 and have been going to the gym for the past 1 month. I had a workout class in college but stopped after that and just periodically worked out at home. I weigh 142 (average weight) and have really low body fat (5-7%). When I go to the gym I get exausted really quickly. I think it is because my body does not have anything to convert to muscle. I am wondering what I can drink or take that is safe and natural that will help me with this problem. I started to eat protein bars but am not sure if its good enough. I dont want to become huge and ripped like most men strive for, but I am want to be in shape and have decent muscles. I have a really good body physique (\ /). Please help if you can.