The latest in the long line of fitness mash-ups—the half-spinning, half-yoga class—is showing up at gyms all over town. The goal (aside from sparking a hot new health-club trend) is to burn fat then loosen your quads and hammies so you’re less sore the next day. At SoulCycle’s Tribeca studio, cyclist-yogis do 30 minutes of hills and intervals, then 30 minutes of power-flow poses ($38; 103 Warren St., nr. West St.; 212-406-1300). A new class at Flywheel Sports called Fly ’n Flex pairs a 45-minute ride with a half-hour of Vinyasa yoga ($40; 39 W. 21st St., nr. Sixth Ave; 212-242-9433). And Equinox has just introduced Cycle In/Yoga Out, with 45 hard-core minutes of each (multiple locations; Equinox.com).