engadget say it better than I can

"CNN writes about the weight-loss wows of DDR (Dance Dance Revolution), the arcade game from Konami which is sorta like a combination of SuperSimon and the old school Nintendo PowerPad. Apparently portly schoolchildren, used to sitting on their asses while playing video games, have found DDR’s workouts so beneficial that they’re actually losing weight — and some schools have even been incorporating it into PE classes. All of which seems truly sad if you’re a critic (aren’t we all?), but super fun if you’re the lucky fat kid." Lose weight the Dance Dance Revolution way