Green gyms burn your energy while sparing the power grid's With the cycles, the flat-screen TVs and, of course, the air conditioning, most people who exercise at gyms are working out the electrical grid along with their muscles. But the members of AC4 Fitness in Goleta will be generating power and feeding it back to the grid every time they step on a treadmill or elliptical. When they need a drink, they'll have to bring their own refillable bottle and get water from a hydration station that provides free water filtered with reverse osmosis. And when they stash their belongings, they'll do so in lockers made from recycled plastic. "If we're enabling people to be good stewards of their own bodies, it seems like the natural progression of that is to also be good stewards of the environment," said Tony Calhoun, 54, who opened AC4 Fitness in mid-June and plans to run it with as little paper, plastic and energy as possible. AC4 Fitness is one of the more thorough examples of the so-called green gym, a trend that has been growing in recent years as more fitness centers embrace electricity-generating workout equipment and other strategies for reducing their environmental impact and improving their financial bottom lines. In the last year alone, several universities, including UC Irvine and Cal State Northridge, and private gyms such as the Greenasium in Encinitas, have installed workout equipment that generates, rather than saps, electricity. Chapman University in Orange plans to have equipment installed in August. Byron Spratt, 34, was inspired to co-create the Greenasium after "years of going to a big gym and seeing the TVs and the AC blowing and the lights blaring in my eyes," he said of a situation he found especially troubling on days when the weather was nice and nobody seemed to be in the gym. So much power was being used, we thought we'd be more responsible. The Greenasium, which opened in August 2010, has floors covered with mats made from recycled tires. The dumbbells are previously used and refurbished. Sports drinks and energy bars are not offered for sale in an effort to reduce waste and plastic. If clients need water, of course they can have some. They'll just have to drink it from the club's reusable ceramic mugs or a bottle they've brought from home. Still, "we realized we couldn't be 100% carbon-footprint-neutral in the workout studio," said Spratt, who tries to reach the gym's carbon balance with community service. Each month, Spratt and the rest of the Greenasium staff participate in beach cleanups with the nonprofit environmental group Surfrider Foundation. Every other month, they volunteer for a local e-waste recycler. "Kinetic means if you take action, you can achieve anything," said John Scarangello, 47, owner of Kinetic Cycling in Brentwood. The popular Westside spinning club has been using five electricity-generating cycles since the club opened three years ago. Together, the bikes generate 600 watts of electricity per hour when in use. "We call it good energy," added Scarangello, who this summer will open a second workout space outfitted with silent Woodway Curve treadmills that are self-sustaining and use no electricity. The entire space will be lighted with energy-saving LEDs. David Solomon, who is such a regular at Kinetic he is known as "the king," makes a practice of working out on the electricity-generating cycles. "It's a great workout," said Solomon, a real estate investor who spins at Kinetic three days a week. I like to think that in my small little world, I can make some little difference to the environment.