Fitness instructor is a sales profession and a sales of self-ability. When you are free, you can chat with other private teachers and talk about this requirement casually to see if other private teachers also have this requirement. Because some private teachers want to expand their business, your exercise results are also the results of his professors, which will be used as positive publicity to improve your performance. Let you hand in your homework and see if you bounce back or slack off in the future, because you are his advertisement and the facts are more convincing.

But there are also negative thoughts. If it is only his personal request to you, maybe he has some intention to contact you as an excuse, then it depends on your own likes and dislikes.