Great question and some good responses, especiall from edt - the better I get as a kiter, the more I relax and expend less energy. My two cents as a former/reformed personal trainer and almost old guy (nearing 50) is that I still get to the gym and lift at least three days a week but what I really find helps with kiting and fatigue is any exercise that improves my ability to process the air I breathe, anything that makes my body more effective and efficient. So HIIT is good, crossfit can be good or something as simple as a killer 30 mins on the stairmaster at warp 9 or whatever feels like warp 9 to your body (five days a week for desk jockeys like me or if you aren't doing anything else, but you sound like you are very active and in fine shape).
Also, I spend some time every couple days on a balance board from these guys https://www.vewdo.com/
As I get older my reflexes and general co-ordination isn't as sharp as when I in my 20s or 30s, so the balance board stuff really works for me.
If you come across some other tips, feel free to share.