Just for reference I used to work with a gym that cost around $4000 USD a year, 272,000 square feet, resort style spas, plastic surgery, three weight floors, tennis courts, basketball courts, expensive restaurants, 3 olympic size pools, physical therapy, the works. My first year working 6 days a week I earned 30k, and ended up about 1k in debt due to the cost of living. After moving from salary to commission, you might earn 20-30 per client. Keep in mind that the client pays $62 USD/hour and up. The top earner at the gym, a gregarious guy named Bob, worked 12-16 hour days 6 days a week to earn around 95,000 USD a year. Considering the hours he worked and how physically demanding it is, that is paltry.