Pilates, HIIT classes, lifting and spending hours on the StairMaster — all popular forms of exercise that come with grand promises to transform your health. But it comes at a cost — both in the literal and figurative sense. Classes and gym memberships can run up to $300 a month, and go...

Pilates, HIIT classes, lifting and spending hours on the StairMaster — all popular forms of exercise that come with gr...