Duh, because it's a pesik reisha delo nichah leih :D
Oh and mybe a Sofeik Pesik raisha
And if he's very good, and if halachikly allowed 2b there, then it's a dava sheain miskavein. Oh and did I forget about misaseik. Althought the question begs to be asked, what is the PRIMARY eisek of someone in such a gym
I don't think It's the workout....