I hear you, Dereck.
I'm 45 myself, and recovery is definitely slower than it used to be, but I feel the same way as you do about not letting age stop me. I may have to make adjustments to my workouts in the future, but I'll deal with that when the time comes.
These days I let my body tell me when it's time to take a break instead of having a certain set time period.
When I'm eating right, sleeping enough, and doing everything like I should be, and still feel burned out, then it's time to step back.
When I feel strong again and am thinking about working out a lot, then it's time to get going again.
I understand what you mean about losing focus in the martial arts as well, and I think it happens more often than people like to admit to.