Why the emphasis on forcing anyone to run? There are plenty of activities that burn a decent amount of calories:
Running 7mi/hr = 700 kCal
Walking 3mi/hr = 240 kCal
Swimming 1.7mi/hr = 550 kCal
Cycling 13mi/hr = 560 kCal
In-Line Skating (1hr) = 426 kCal
Jet Skiing (1hr) = 400 kCal
Beach Volleyball (1hr) = 484 kCal
Frisbee (1hr) = 208 kCal
Soccer (1hr) = 600 kCal
Football (1hr) = 500 kCal
Kayaking (1hr) = 346 kCal
Surfing (1hr) = 208 kCal
Yardwork (1hr) = 270 kCal
Car Washing (1hr) = 200 kCal
These are very loose approximations based on someone weighing around 130 lbs, which would cover your heavier kids. If the point trying to be made is to get kids more active, I'm all for it, but the focus on running is just asinine. Hell, if a school doesn't have funds to cover extra equipment, encourage and help organize the kids to fundraise doing car-washes or basic yardwork.
As for the suggestion to reward kids at the end of the week with doughnuts...really? Y'know, if there was an effort made in education for proper nutrition and eating habits, that would go a long way as well.
All this said, I disagree that the schools should be the ones forcing this. Parents can simply restrict some forms of sedentary entertainment; that alone will get kids out of the house doing stuff.