Originally Posted by va_cyclist
Sounds a bit high but not far off. caloriesperhour.com shows 1,247 calories burnt for 1 hour of "vigorous" (14-15.9 mph) cycling, or 1,497 for "very vigorous" (16-19 mph) for a 275-lb. person.
Sounds way off. I maybe burn 400 calories/hour at tha 14-15.9 mph range for cycling. And very vigorous is more like a 22-25 mph avg.
I probably burn 1125 calories/hour in a race- like with an avg HR of 179 bpm.
This is the closest thing to accuracy that I've seen:
http://www.kreuzotter.de/english/espeed.htm
You can delude yourself thinking you are really burning a lot of calories per hour... but you might gain a bunch of wait in the process. Of course, the worse shape you are in, the more you burn at a given "speed."