My wife is 9 years younger than me. She doesn't have any joint issue.
I strongly believe that if you don't use it, you will lose it. The more you use your joint, the more fluid will be generated in your joint.
This is one of the issue to train MA. After you have spend your life time to develop something, it will take the rest of your life to maintain it (if you don't want to lose it).
That I agree totally. I work harder today than 10 years ago. I always hate walking and running, so all my aerobics are punching and kicking. My legs are naturally stronger than my upper body. Like when I do leg extension in the gym, I usually use the full stack of weight( over 300 whatever number). I was squating 265lbs(not a deep squat though) until I fell a pinch on my back and I was in pain for over a week, then I had to stop squating that heavy. So I don't really work out that hard on my legs.
I never felt pain in my lower body..........until 4 years ago ( just turn 65), one day, I walked down the stairs, my knee buckled, I almost fell down the stairs. My knees started to hurt!!! Then my foot started to hurt also. 65 was the magic number!!! Never have pain in my lower body till that time, always strong. I since put in much more work on my lower body just to get rid of all the pain.
My upper body is never that strong, I really have to work hard on the upper body. Knock on wood, so far so good.
There is no free lunch, you pay now or you pay later being disable. My mother was using a wheel chair at my age now, I determine not to follow her footstep. For me at this point, all the exercise is mainly for being able to be independent, not really for MA or fighting. Hell, for the longest time, I did not even think of MA and all, the routine punching and kicking was only served as aerobics for health. I would never join this forum if it's not for stick fight. It's only because a lot of older Asians are being attacked, that encourages me to pick up stick fight with a cane and more thinking back of MA.
Just to be clear,
I don't mean to say don't walk and run, just pay attention from the experience of my wife that did it 6 days out of the week on high impact aerobics for 20 years and then 6 days a week of fast walking. Mix it up, alternate punching bags and walking every other day to give the body a chance to rest. But if your wife is much younger, maybe it's not an issue at all. This is just my wife's experience. She does put effort in exercise all these years. All the crap happened only when she approach 70, she was in perfect health before that. Younger people ( even in the 50s) might think I am paranoid, but this is life!!! We do get OLD.
I know, for a lot of people, you have to keep telling them to work harder, longer. But there is the other side where the small number of people that do spend their whole life exercising and training. The mentality is quite different, you have to think of preservation as you have the will already, the caution is NOT to over do which result in hindering your goal because of injuries. At this age, you fight to maintain, not to get to the top. You fight to not having aches and pains and be able to be independent.