Originally Posted by
MRT2
The number I have seen is 3500 calories per pound of fat. And I agree that you probably burn close to 3500 calories cycling 100 miles. I would say 10 mph is quite a slow pace and even a moderately fit cyclist can go a little faster, like 11 to 13 mph, or maybe 12 mph as an average, so OP would have to ride 8 1/2 hours to burn 1 lb of fat, assuming he doesn't eat a single extra calorie before, during or after cycling, which is not realistic.
Hence my original point. you can't really lose weight just cycling. I have cycled for years, and found almost no correlation between cycling and weight loss.
This is why they say you can't outride the fork. Sure, you can burn calories but you'll never burn
that many calories. That's also why I find it amusing when people think the solution to weight loss is to exercise.