[xiaoma]

I did.

I once dropped 50 lbs in about three months solely from returning to my previous running habit. At least according to my calculations, I was burning closer to 1000kcal/hour (more like 100kcal/km). I wasn't doing competitive-style twice a day training, either. Just one run, six days a week, usually for 60-90 mins at a BPM of <150. Once a week I ran 800m sprint repeats all-out, and two or three times a month I did a long run (which was increasing by about 10 minutes each time until I got it up to 4 hours).

All in all it averaged out to just over an hour of exercise per day, and the mental benefits more than made up that time in productivity. I didn't change my diet at all, except to eat a bit more after the long runs and possibly to eat a bit more cereal. And I lost just about every spare bit of fat on my body.