Karate is helpful for similar reasons, but thanks to the mindset, it's sometimes more serene. You can get into an almost meditative state even while you're exercising. The best part is that you'll look kick ass even as you're learning to kick ass! In most towns and cities, you'll be able to find at least a few places that offer karate lessons, so that won't be a problem. Again, take a friend along for the ride! Failing that, you can even get a DVD that instructs you in the basics.