My main fitness regimen is kickboxing. I go to a class twice a week, working up to three times a week. We use 100 lb punching bags, wrapped hands and MMA gloves. Inorporated into kickboxing are a lot of warmup moves that involve balance and flexibility and lots of core work. My weak hip flexors and slowly getting stronger. My reflexes are getting much faster, and my strength and stamina is increasing. The belly fat that had started to increase (I'm 50) is now dissipating. I also like that I'm learning some self-defense!
My instructor is a women's national jujitsu champion, and at 4'8", she's a powerhouse. She is excellent at modifying moves when said move is too difficult for someone who may be dealing with injury. She also makes our workouts fun....no one is ever the same, and she moves around to give everybody individual feedback. She pushes us hard, but she makes us laugh, too
I have the option to work with an individual trainer in the boxing ring. I'm not ready for that year, though it would be cool!
I also run half marathons. I only run about 3x a week, and like the quiet meditative time that this provides. I have arthritis in my left knee and actually, running has kept it at bay, probably because steady aerobic exercise increases blood flow and builds capillaries, and is good for the heart (my resting HR is now in the 40's).
I used to lift weights when I was a competitive cyclist; I got injured for doing too much weight.(Broken lumbar vertebrae that took months to heal). I have no desire to lift weights anymore, but......doing so is really important for strength building. I just have to use body weight exercises, a 100 lb bag, and a medicine ball instead.
Everyone has their own best method of working out. There's definitely no one size fits all! I've enjoyed reading about everyone's varying routines here. It will be fun come ski season to see who feels their exercise routine has really benefitted their skiing.