Gym teachers and athletic trainers who are out of shape

In high school, there was a gym teacher who was obese. He was obese as in he was fat but seemed like he is active and can run and is athletic. That teacher was very nice and social but his body weight made people laugh about him a bit. The point is that gym teachers and athletic teachers that are out of shape are instructing people that are athletic or are trying to loose some weight and for the instructors to look like a student/client just seems to imply that they themselves are not physically fit. They may be very excellent gym teachers, coaches and athletic trainers but if they look like they need to get in shape as well. It would seem as if they need to workout and get in shape before they begin instructing others how to become athletes or just simply loose weight.