Hi guys new to the form so apologies if this is in the wrong place. I trained in TKD when I was younger but after about 15 years and 3 kids later I have decided to try my hand at kickboxing. I am reasonably strong and i know technique will come back in time through traing itself but I am severely lacking in fitness. What do you find a good way to supplement your training for the fitness side of it. Long distance running? HIIT sprints? Lightweight circuit training? Any advice is appreciated.