Gents, stop abusing your bodies by working out too much and eating too little (or too much garbage). Start here: http://www.marksdailyapple.com
Then, read this: Good Calories, Bad Calories
by Gary Taubes; find out how calories in, calories out is BS. Then, read this: The Omnivore's Dilemma
by Michael Pollen; find out all about the food available to you - this book is fascinating and scary. Learn about Grass Fed Beef, coconut products and better choices when it comes to food. Between these three, I feel better than when I was in high school, am stronger, am about 8% body fat and now know far better how my body functions, what certain foods do to the body and which foods to avoid at all costs. Stronglifts 5 x 5 programs are excellent to begin with as well, and are a 3x weekly exercise routine. Whoever is working out more than that, at high intensity, is going to hit walls and fatigue their bodies.