My boy has seen exercise as a part of my lifestyle his entire life. He currently plays lacrosse, it will be his third season this year, as well as skating, Sportball, etc. He could balance on the BOSU at 2 years old, likes to show me his yoga moves and loves boxing videogames.
I caught him on camera experimenting with a few of my tools, and I can see him working up to a video or infomercial in the future. He loves to show his friends what I show him, and I've even stopped in at the school to do a little talk about exercise. When I drop him off at his Sportball program he tells me that he's going in for his workout :) I hope I've set a good example and that he'll consider exercising to be a very important part of a happy life!