Originally Posted by Askel

Even the most highly trained athletes can only store 2500 calories or so of glycogen at any given time.

Assuming an average day of 2500 calories eaten, a 272 pound rider riding 42 miles should burn way more than 5000 calories even if he does almost nothing else.

Break even? I guess I can buy that.

Gain? Nope. The numbers don't make sense unless you have a godlike capacity for stored glycogen.

And lets not forget, the calories in that glycogen had to come from *somwhere*. They didn't magically appear out of nowhere. As I said before. It's not day to day or even week to week. It's the average over a long, long period of time.