About 7,500 people have taken part in the annual Krispy Kreme Challenge in Raleigh. The rules are simple and stomach-churning: run for two miles, eat a dozen Krispy Kreme doughnuts and then run back along the same two miles.
That's four miles of running to burn off about 2,400 calories.
It's for a good cause, though. The race is operated by students at North Carolina State University, and it raises money for the North Carolina Children's Hospital. Last year, the event took in more than $55,000 (£34,000).
The race began in 2004 as a dare among friends. Only a handful of runners took part in the beginning, but it's grown steadily since then.