Strava usually says I burn around 1000 calories an hour, I assume thats overestimating by about 300 calories or so. All I know is that when I get home I am competely exhausted and feel terrible for 2 hours or so. I think I need to eat more on the bike, I usually eat 200 to 300 calories during a 2 or 3 hour ride. And I lose weight when I don't want to. I thought cycling would grant me larger thighs?