There are thousands of health clubs, gyms, fitness centers and yoga, pilates, boxing, martial arts business etc. all over the world. A majority of these have really bad websites.
This is a huge market for developers to solicit. If you could make a nice template (as you always do) that could be modified to fit these businesses I think it will be a best seller!
Some of the important ares to feature on the front page are:
A slide show showcasing the place
What services they offer
Promo section for promotional incentives to join
Link to class schedules
Link to member forum
Success stories (before and after pictures)
The class schedule will be an important part and should be easy to modify and update.