RE: Actually a loaded question
We always burn a combo of carbs & fat unless we're anaerobic when we burn carbs. So I didn't mean to imply a low carb diet was the way to go. Just the opposite.
Don't take my opinion on this. Check out a sports nutrition book at your library or bookstore. I really like Nancy Clark's book. Ellen Coleman & Liz Applegate also have good books. Look for a book written by a R.D. (registered dietician). Applegate isn't an R.D., just a Ph.D. in nutrition & is on U.C. Davis's faculty.
When you're reading, look at the creditials of the author & whether there is a potential for bias. Medical doctors are generally not required to take more than one class in nutrition, if any. Look to see what the author is selling. Magazines, look at their advertisers.
Some online sources include WebMD.com, mayohealth.org, & eatright.org.
Debra