How old are these children he is judging as wimps and calling out of shape? There are many different forms of athleticism, and kids don't necessarily discover their inner athlete in nursery or grammar school. My youngest is dyslexic and never could see the ball right. Didn't play any sports all through school. I guess some people might have called him names, but he liked to cook and do things around the house.
Then, when he was 14 he said he wanted to be a lifeguard, but was afraid he wouldn't pass the test. I told him, "unless you try it, you'll never know if you can do it or not." That boy has been a lifeguard for the past 6 summers. He surfs, scuba dives, wakeboards, kiteboards, and I don't know what else. He turned out to be an athlete, just a different kind. His thing is water sports. He developed a nice, strong body with just a couple of summers in the ocean.
You need to talk to Dan about how bad it is to compare children. As a teacher, you know how unproductive it is to wonder why your kid isn't like someone else's kid. Each one is special and needs to be appreciated for who he/she is.
