what I suggest is a program of weight lifting and aerobics, especially triathlon. Swimming, running, biking. Fitness is key for so many things in life. Once you reach your potential (which will take a year). then take 6 months of a very serious striking sort of martial art, then 6 months of brazilian jiujitzu. NOT the grappling first, cause it requires more muscle than a teen can develope, and it gets you to value "going to ground" too much. Bigger, heavier people, especially if there's more than one or if there's a weapon, are NOT well handled with grappling. You have to hurt them from a distance (and then flee, or go find a weapon and come back to finish them off.
Then about as much more training with long and short sticks and the knife. People get attacked every day. They do not get into shtf stuff once in a lifetime. Your fitness training might as well be defensive training, but it can't be so, unless you've already built the fitness! Once you have a notebook full of what you can do and how often and for how long (running, pushups, pull ups, standing broadjump, standing vertical jump, swimming) a simple test now and then will tell you if your defensive training is letting your fitness fall off. If that is the case, then you'll again have to work some specific type of fitness training into your schedule. Put a very heavy emphasis on training your core, with abs and back muscles being used. They are a major aid in a fight, in a car wreck, and help prevent back injuries at work.