The single best distraction while you’re on a treadmill or an elliptical machine, in my opinion, is watching tennis. That’s why I throw off my entire workout schedule during the Australian Open and go to the gym late, at 9 or 10 p.m., when the matches start on TV in New York. In my darkened neighborhood, my gym stands as a shining beacon of the 24-hour fitness craze. Usually only a few people are there at that hour and working out in relative solitude makes it feel like the gym is my own big fitness playland—All this just for me? But if you think of it in an environmental way, it doesn’t seem so nice. Almost all the TVs glow for no one, stark lights buzz all around, ceiling fans whir: What a waste of energy.

That’s why the idea of green gyms is so great. I know what you’re thinking: Another go-green blog? But check out this video on the Green Microgym in Portland, Ore.

Pretty cool, huh? While members toil away, trying to get fit on bikes, ellipticals, and treadmills, they also create energy to help power it all. The gym now has solar panels that capture 8 kilowatts of energy per day, which covers 40 percent of the gym’s energy needs. Adam Boesel, the owner of the gym, sees this as just the beginning. “I think 20 years from now all gyms will be putting electricity back into the grid,” Boesel says. “It’s not going to be a trend, it’s just going to be a given.”

Even easier than the harnessing of human power, though, is something all gyms can do: conserve. At the Green Microgym, members control the settings of everything around them. If they need light, they turn one on. Same if they want to watch TV. When they’re done, they turn it off so it’s not sucking energy. “Gyms have to focus just as much on saving energy as they do on creating energy,” Boesel says. “They have to take a look at all of their practices. From the cleaning supplies they use to what kinds of water bottles they sell.”

So next time I’m watching tennis during a late workout, maybe I’ll turn off the TVs around me, and maybe I’ll ask the managers if they can make energy conservation a gym policy. Because working out shouldn’t just be about looking good, but also about having a healthier lifestyle—one that benefits both you and the environment.