An eco-friendly gym grows in Brooklyn, it’s true. With bamboo floors, recycled rubber mats, and remanufactured, energy-efficient exercise equipment, the Green Fitness Studio is building a more sustainable gym from the ground up. And we mean all the way up: The “living” rooftop features a 2,000-square-foot blanket of sod, designed to absorb pollutants, conserve rainwater, and reduce storm weather runoff.