Yeah I was thinking about the squats/leg presses factor. Well if you've done your HW, good luck. Its good to start ppl off early. BTW if you put them in Karate, MAKE SURE its Kyokushin, and not the other styles .. cuz I was in "Goju-Ryu" when I was 8 and it didn't do shit for me. If you can't find a Kyokushin school, send them to Muay Thai/Kickboxing or Wrestling or Brazilian Jiu Jitsu and if you love your kids, you will not even consider Tae Kwan Do.