Coss Marte started selling drugs at age 13 and by 19, he says, he was making $2 million a year. After serving a prison sentence, he founded a "prison style" fitness boot camp. Justin Fennert/Courtesy of Behind the Stache hide caption

itoggle caption Justin Fennert/Courtesy of Behind the Stache

If you're overweight, the best way to spend your limited time exercising is aerobic activity, a researcher says. Rhodes ludovic/iStockphoto.com hide caption

itoggle caption Rhodes ludovic/iStockphoto.com