I know that I shouldn't fret over this so much, but I've got to say it again. I'm really, really tired of people who attend the cardio kickboxing and cardio bootcamp classes at my gym, and yet who scarcely put any effort into their moves. I'm talking about the ones who don't put any 'oomph' into their motions and who consistently adopt the posture that requires the least amount of effort and expends the least energy. (For example, doing knee raises while standing straight up, rather than leaning forward and bending the supporting leg.)
Yeah, I know. Ultimately, it's their choice, and that's true. The problem is that they're often distracting and even painful to watch. They're also demotivating -- and I'm not just saying that, since I've even heard an instructor say the same thing.
I know it sounds harsh, but it's kinda annoying to see people put in the time but not the effort -- to basically throw the time away. It's also annoying because some of these folks wind up chatting amongst themselves instead of doing the moves. They are also likely to let loose with whines or groans when the going gets tough, instead of just doing the best that they can.