When sedentary kids strap on this Fitbit-like wearable, they might start exercising—at least temporarily. But they'll work out harder and longer if they know that their activity is also helping someone else.
The Kid Power band, developed by UNICEF, lets kids use exercise to "unlock" a donation of a food packet to a child in need somewhere else in the world. Over the past two years, independent research has found that the program's combination of philanthropy and activity works: Children in the program—most of whom come from low-income backgrounds—are 55 percent more active in a day than kids who only have a fitness tracker. A second study found that children using the program met their daily activity goals 30 percent more often. For low-income children, where activity gaps are most prevalent, these jumps are especially significant.