I agree with the adoption of a sport. If BJJ is not quite up your alley may I suggest running? 5k, 10k, half marathon, marathon... which ever you can see yourself enjoying most. I've tried running, BJJ (blue belt), crossfit (injured myself), softball, flag football, and soccer and I alway come home to racing. There is nothing quite like it. When I, as a man in my mid 30's am racing down the last 100 meters against a 65 year old I can't help but think they have found the fountain of youth. The confidence, friendships, and experiences races build are things you can treasure forever. The only drawback I have found is the emaciated look that serious runners develop after prolonged training (months to years). It does sound vain but in reality that is what has kept me from pursuing it even more competitively. I'd love to hear the thoughts of other runners out there, is this an issue you struggle with?