SouthNarc makes some good points. Having said that, while I'm in pretty good shape for my age, I shudder to think of what might happen should I attempt the mandatory yearly PT test I did last in 2015. I used to joke about how part of the weight we carried to simulate gear should include an Oxygen tank past a certain age. I've noticed that what I don't have like I used to is stamina.
A bout with pneumonia a couple of years ago proved to me that if you REALLY need that cane, walking stick or whatever, your best move is to get your back up against a wall for support. With the exception of the stuff on the canemaster website, most "training" features 30 something dojo rats, not us old farts who really need it and moves we might be able to actually make.
I've no idea (and I should have) what moves might resurface from the memory banks at need. I do know that if the effort doesn't take the foe out of the fight right then and there, I'm not gonna outlast him/her/them. Have to maintain the alertness at a high level and avoid such threats as best I can.
Predators-regardless of species-generally avoid alert & healthy prey. Maintain your awareness and do your best not to look like the weak and unsuspecting victims they prey on.