I studied Ninjitsu for 2yrs a long time ago and I did amateur boxing in undergrad. If your goal is to get fit and also learn how to kick someone's ass, start b

I studied Ninjitsu for 2yrs a long time ago and I did amateur boxing in undergrad. If your goal is to get fit and also learn how to kick someone's ass, start boxing. Don't get me wrong, martial arts are a great discipline, but I've never ever had a workout session in any sport or martial art as intense as my boxing practices. Hitting the bags or sparring with someone tests your stamina/endurance real quickly.