I'm surprised!
1 Timothy 4:8 always seemed to be the scripture that made Witnesses shy away from the gym. After all, that's time you could of spent on "kingdom interests".
It also made me wonder why being obese isn't a disfellowshipping offense. If smoking is a disfellowshipping sin because the smoker is intentionally desecrating his body ("temple") then why isn't sucking down $0.99 cheeseburgers at McDonalds? You are always more likely to run into a Witness around 11:00AM at a McDonalds (field service break) than at anytime at a gym.