[barking]

I thought that until someone explained to me that the 100 calorie figure includes ALL the calories burned during the time the run takes. If you run 10 miles in 1 hour that's about 1000 calories. But lying on your back burns up 100 calories per hour. So running only accounts for 900 or 90 per mile. and also the number of cals burned is proportional to your weight to some extent.

EDITED to correct some bad arithmetic :(

[jedbrown]

On the flipside, exercise increases your metabolism during the rest of the day, typically more than offsetting your math. This effect is well-correlated with exercise intensity. Also, 100 calories/mile at 6 minute/mile pace is quite efficient unless you are very light (e.g., 140 lbs).