They do HIIT or high intensity bursts then go slow then another burst.
They combine this with regular strength and aroebics for a class of 45 minutes.
I did HIIT and it is superb. Best thing is the hard work bursts last maybe 30 sec. You can walk on fire for 30 seconds so psychologically it is easier than other workouts and you get into shape rather fast
The group class compels you to work hard because everyone else is and we are group animals
I cannot recommend it though as I am just reading from thier web
BTW, most of the gyms out there have gone the way franchises.
I , for one, would not buy such a franchise because of competitive risk but the owners are highly motivated