A little embarassing, but I've struggled for years with my weight, although my zest for cycling has steadily gone up, now to the point where I'm actually doing it on a very regular basis. Right now I'm 6'4", 258 lbs, and according to measurements an estimated 31% BF. I am training for a 70 Km mountain bike race in June, known as the Test Of Metal. My training consists of about 150 Kms a week of LSD, including commuting to work, a weekend 2.5 hour MTB ride with a group on some tough technical trails, as well as some cross training with swimming, some weights and a little bit of running. My goal is to lose 40 pounds of fat which would get me down to about 15% BF. My question is how much of the weight you lose by eating a healthy diet and an exercise program like this is fat loss, how much muscle? Is there anything I can do different without spending more time, I have 4 boys under the age of nine, to make sure that I maximize fat loss and minimize muscle loss? Does this seem like a good approach to gear upfor the race I have signed up for? I hope this post makes sense and any help would be greatly appreciated.