I've had two so far. The first session was basic offensive moves, the jab, cross, hook, and uppercut. Session two was about defense, parrying, blocking, bob and weave, the slip, etc.
It is a pretty intense upper body workout. My arms were quite tired and sore the first week, not quite as bad today. Also some cardio because of the footwork and movement.
Not really doing this for aggressive reasons by any means, I have no desire to go there. I have some left side weakness that is fairly noticeable, as well as some balance issues. I asked my neurologist about this a few months ago, she thought it was possible I may have had a small "silent stroke" at some point in the past, although she was just speculating. So, I hope it helps with that, with overall fitness, and with mental outlook and self-confidence. Not something I imagined doing at my age, but hey, you stay young by acting young.
I am working with a trainer one on one, but I met a few other members who were taking a group class, and let me just say, if I ever have to spar with any of them, I would be one scared man - those ladies are TOUGH!