The latest gym machine to take its inspiration from outdoor sports: SurfSet Fitness’s Ripsurfer X, a cardio and resistance trainer designed to mimic the motion surfers use while paddling out and engage the same core and leg muscles they use when popping up and carving a wave. Classes are available in New York City and Boston, with additional locations being added this spring. The company also has a home version. Our take? It will keep you in surfing shape, but it won’t have you springing out of bed for dawn patrol.