There is also a boast that your figure is good enough, and you don't need exercise to lose weight! In fact, he doesn't know that the reason why you are in good shape is the result of your persistence in fitness exercise!
Perhaps this is a common problem of most people, who think that if you are in good shape, you don't need to exercise. ...
If you like him, you can invite him to the gym, otherwise you can tell him that you like fitness.