“I thought maybe I could get a little fitter, and do some cartwheels.” These were the modest ambitions of Zach Fischer, 27, when he joined Athletic PlayGround in Emeryville a few years ago. But Fischer shocked himself. “I can do a backflip now. And that is something I never thought I could do. I thought I’d missed my window of possibility long ago, when I was a kid.” Fischer has even started teaching an acrobatics class at Athletic PlayGround. Athletic PlayGround draws its inspiration from the circus, and provides a place where people discover “they can do things they never thought they could do,” says David Grace, who started Athletic PlayGround in 2008 with Shira Yaziv. And like the circus, the atmosphere is playful, high energy, and, well, alittle wacky. One member often dances around the gym between rigorous sets of strength and balance exercise. Two others always appear with colorful, mismatched striped socks. And there are monkeys everywhere – monkey toys, monkey murals, and humans doing monkey-like things. “Monkeys are very strong … and very playful!,” says Grace, adding that the gym offers Monkey Conditioning classes every day of the week. In addition to weekly classes, Athletic PlayGround offers