I actually feel this same way often. On my days off I will get everything done, house chores, errands, and then I will be bored out my mind. I will look for more work to do even though I want to relax. I often feel like there is something I should be doing even though it's probably all in my head. Sometimes I will read a book or play a videogame to help keep my brain occupied. It is very hard for me to just be idle.
Fortunately, I have various religious observances to keep me active, but I find too much of that wears me out too. I like to be busy. It's when I'm idle that I end up smoking and drinking.
I can relate to this. I love weight lifting and when I discovered high intensity training I was hooked, but it took a long time to really get comfortable with the fact that if I did HIT I couldn't do it more than 2x/week (MAX!) if I wanted to get good results. Doing it 2x/week wasn't an option if I was doing any kind of physically demanding MA training at the same time, and even at once a week I had to time it right with my MA training, especially as I got older. I've found that I can focus on skill development training without causing my body significant stress. This is easier with some arts than others, but I can usually find something that I can practice that's more brain work than hard physical work, but still has a low intensity, physical, component. I also do a lot of walking when I'm feeling like I need more recovery but still want to do something physical. It's healthy, it gets me outdoors and away from screens, I find it mentally relaxing, and my wife will often go with me and it gives us great, uninterrupted time to just chat and be together.
So do some kata. Movement is good for muscle soreness, so long as you aren't adding insult to the injury.
Jolly good
