Can't get outside but want to break a sweat? Fitness centers nationwide are finally jumping on the green bandwagon, as reported by rueters.com. While the health club industry saw an overall increase in business last year, many are aiming to increase that even more--by tailoring to eco-conscious customers. From recycled treadmills, to green building practices, fitness centers are going the extra mile on the green track. Our personal favorite? Go Green Fitness, which connected 25 of their spin bikes to generators, so that members can check their heart rates and their wattage at the end of class. Hows that for recycled energy?