Remember when you choose a trainer or instructor...
With the explosion of interest in physical health, has come an equal explosion in the training profession. There are many qualified experienced trainers and coaches in your town or city, I bet. Unfortunately, there are many who are not qualified. I am writing to recommend you do a bit of research or check before signing up for a class or individual session.
Here are my tips to give you confidence in your coach. Ask your potential trainer:
Education -- I recommend a trainer with a degree. It can be in physiology, physical culture, sport sciences, or medicine. People with a degree have studied anatomy, physiology, biomechanics, and more. Perhaps attending a Zumba class with an enthusiastic, less trained instructor is ok, but someone committed to improving overall health, recovering from or preventing injuries, or developing in a dedicated sport will be served by a learned coach. As an example, Private Pilates coaches in Australia are not allowed without medical education. This is wise.
Ask for a certificate by discipline, e.g., Physical Therapy, Pilates, Gyrokinesis... Respected schools post certifications on their websites. My Pilates certificate is from Merrithew https://www.merrithew.com/instructor-training/bios/marina-goddu
Teaching experience -- Minimum 3 years, with about 1,000 sessions per year. It's like a physician, if you don't practice a lot, you can't become a good doctor.
Take a look at Google reviews and Social Media posting. You will sense the professionalism.
In summary, I believe that trainers with serious education and solid experience should teach and coach. On a final note, the coaches who benefitted me the most had these credentials AND were passionate about their teaching and students.