TKD is a great way to start to teach young childern and I have been training my three since they could walk, now with that being said I teach them the sport aspect in the beginning the around 8 I start to teach them more traditional TKD and around 12 joint locks and more advance, childern need to get into the Art as soon as possible for once they hit a certain age they will not attend for it is not cool to do MA it is better spent in front of a TV or a video game.