I have been doing aerobic dancing exercise classes for 30 years. The problem I have with QCDO and their Zumba is:
1. No technique is taught. It's a free-for-all. The motto "As long as you are moving, you are doing it right" should be a red flag. If you are not doing it right, you can injure yourself.
2. No attention is paid to stance or posture.
3. No review of steps by instructor for newbies. No verbal commands (e.g., grapevine step right or left, side step, pony, etc. )
4. Worst of all, no water breaks or intermittent heart rate checks. You're on your own.
Workouts like Jacki Sorensen or Richard Simmons are still the Gold Standard. For this group, proceed with extreme caution.