1. I thought gender-based discrimination was illegal. How is Leap not illegal?
2. One of the main objections of "gentleman's clubs" was that their (male) members had access to important networking contacts, putting women in unequal foot in an unfair way when it came to businesses. Wouldn't Leap be unfair in the same way?
In some states, AFAIK the "women-only gym" is allowed, but in others it isn't. The point, if I remember correctly, is "exercise requires such compromising clothes and positions, that the right to personal privacy trumps the right to not be discriminated based on gender". And even then, this is not a 100% clear case. Toilets and physical activity follow a similar (although less polemic) pattern.
Having said that, and as far as I understand, you need to show that discriminating based on gender is so important for your activity that it can't be done in any other way. My gut feeling is that, should anyone sue Leap, clearing that barrier would not be trivial.
I would appreciate a lawyer's point of view, and was hoping that Leap had already talked to one that could give a properly researched answer.
Edit: I found a very interesting article[1] about the law when it comes to all-female health clubs. As expected, the conclusion seems to be "it's complicated".
[1] http://digitalcommons.law.yale.edu/cgi/viewcontent.cgi?artic...
Any man taking such an action in 2018 would likely lose their career over it.