That's a tough one. Each person has to find it within themselves. You can lead a horse to water but you can't make him drink. A black belt that gets winded walking upstairs is no blackbelt in my school. I'd bust him back to blue and tell him when he gets back in shape I'll give him his black belt back.
People really don't get it or choose to ignore it.
You could ask them each day what they had for lunch. Then tell them that's one pushup for every fry they ate that day. ;a ;a You would make some friends this way.