I’m 33 and have been training at Igor Gracie’s Westchester school ( http://igorgraciejiujitsu.com/ ) for about 6 months. There really is nothing like it for me. I can come in on little sleep, feeling anxious or crappy and get completely absorbed in the class — forgetting anything else — in about 5 minutes. It really is one of the more rewarding things in life, the skill of it as well as the exercise. And yeah, my wife will still yell “JIU JITSU CHOP!” no matter how many times I correct her.