The mezzanine-level walking track is green, the ceiling is blue. The windows look out onto a sustainably built roof of succulent plants. It’s almost like you’re outside. But it’s not raining on your head. Or it’s not 105 degrees. It’s clean and climate-controlled. And it’s free. If you get dizzy walking in circles, you can pop next door for $3 yoga, Zumba, Barre, and the like. Or if the rain stops, you can hit the greenway that winds through McCabe golf course and baseball fields.