So many are so wrapped up in all the "cool guy" tactical gear (myself included!) that we lose track of how important physical conditioning is to any defensive situation. "Running out of steam" in the moment of truth is not an option and adrenaline can only take us so far. 45 minutes to an hour a day is all one needs to get into fine condition. Combining cardio with some strength training in a Crossfit styled approach is your best bet. Explosive bursts of energy is what is often needed in a fight so any exercises that will contribute to that end will be beneficial such as wind sprints, jumping rope, etc. I've included a video from James Yeager's Tactical Response as one way to make training fun! Enjoy!