Running is good for you, but what if running were also good for someone miles away? CharityMiles is a new iPhone and Android app that lets anybody donate to charity just by running, walking, or biking.

The premise is pretty simple: Users choose whether they’re going for a run, walk, or bike ride, and then choose one of several partner charities. The free app automatically calculates how far they travel. CharityMiles donates $0.25 for every walking or running mile and $0.10 for every mile biked.

The goal is to turn daily exercise into a charitable activity, not to make fitness a drain on your wallet. All those donations will come from corporate sponsors willing to — quite literally — foot your bill. It’s an all-around win, says Gene Gurkoff, the app’s founder. Brands and corporations get to associate with great charities, users give to charity and stay healthy without spending a dime, and CharityMiles — a for-profit company — gets to keep a small corporate commission.

CharityMiles is one of the latest companies trying to initiate social change in a sustainable way. Rather than force people to change their habits, the app gives users a way to add philanthropy to those everyday activities. Moreover, users don’t even have to open their wallet thanks to the corporate sponsors and donations. Sustainable philanthropy is something Gurkoff picked up while working at the Michael J. Fox Foundation for Parkinson’s Research. He helped create the Team Fox running fundraisers, which focused on empowering people of all ages and fitness levels to get active for a social cause. CharityMiles is also approaching philanthropy from a grassroots angle. Rather than seek out lump sum donations, CharityMiles believes that lots of little donations (a quarter here, a dime there) can make a huge difference. “Lots of littles make a lot,” Gurkoff says.

The app does have some marketing tricks up its sleeve. In order to donate the money after a workout, users must agree to post their activity to Facebook or Twitter. It’s a way to raise awareness for a cause but also a way to promote the app — and the paying sponsor — through the social web.

Gurkoff and his partners are putting up the first million out of pocket and hoping that sponsors will start to roll in once the app launches on June 6, National Running Day. It’s a bit of a gamble, but one that should pay off. “All those people out there walking, running, biking — this is a way to turn their morning jog into something more,” Gurkoff says. “It’s kind of like planning a party and hoping people show up.”

Have you been waiting for an app like CharityMiles to turn your jog into donations or would you rather give money on your own time? Let us know your thoughts in the comments below.