Lots of ways to negotiate this.
It’s not just a matter of what % you get, it’s a matter of who is responsible for what. If the club is doing a lot of promotion for you, assigning you clients, then 50% might be fair. If you’re doing more of the work and bringing in your own clients, then you might be able to get a much higher % than that. As Harris mentioned, you might be best off working out a deal of paying a flat rate rent.