Well, one thing that makes me chuckle is when people (we are all regulars and the others all seem to be tri-athletes or runners) start out with heavier weights for certain sets. I, on the other hand, start out with the ones that I know will let me complete all of the reps, with good form. By the end, the others have put the heavy ones down and switched out to what I use. Of course, I vary the weight by type of exercise and who is teaching. I try not to let my ego get in the way, because I know I am at least 15 years older than most of them. So, they are not babies, but in their 40s, a few are 50-ish and occasionally, we have a young one come in (they can't stick it out!). I often, though, can outlast them in all things cardio, and end up running with 2 of the super fit tri-athletes, who are also the oldest next to me. But, one of them, who I really like, is a bit of an exercise bulimic (new diagnosis), as I have seen her going off to do more on the eliiptical, or run outside after class. And, she's always fighting injuries. It is hard not to compare, but even when I was in my early 30s and teaching at the gym, I could not do what others did... like teach back to back classes a few days a week. As it was, I was sick all of the time from no rest and 7-8 classes a week.
2015 Trek Silque SSL
Specialized Oura
2011 Guru Praemio
Specialized Oura
2017 Specialized Ariel Sport