Yeah, I got the dubious honor to go to a "bootcamp" for free one day. Wow what a shit show.
JF is right when he says you get essentially 0 training in that hour. All old mate trainer does is tell you what to do [ie. push ups, jungle gym etc] and then watches, yells and keeps time.
Once once did the little trainer guy comment on anyones form. Be it running form [we had people running with their head down, toe to toe etc.] or push up form [never more than 4" ROM except for me]. Dude didnt give a shit, or know shit.
the only thing you get is thoughtlessness. you literally dont have to think about anything because you get the luxury of being told what to do at all times. basically you dont have to think about what to do next. but then again that also happens when you pre-program yourself or hire a real strength/conditioning coach.
And mr push ups king trainer guy [we must have done over 200 push ups, well i did. everyone else did about 20 with their collected ROM] couldn't even do a 1 arm push up. FAIL. and the dude only weighed like 160. I was like 190 at the time [i think].
If you want to do a group class for cash then get a yoga membership. At least they are sticklers for technique.