The cartilage in your knees is a living tissue. Like muscle, it responds and adapts to stimulus. If descending stairs gives you knee pain that isn't from some past injury being aggravated, then train them.
You get people who go skiing or running for the first time in a while and they complain "Oh, my knees hurt, I'm too old for this". Nope. You're just out of condition. Use it or lose it.
alt Hacker News
The cartilage in your knees is a living tissue. Like muscle, it responds and adapts to stimulus. If descending stairs gives you knee pain that isn't from some past injury being aggravated, then train them.
You get people who go skiing or running for the first time in a while and they complain "Oh, my knees hurt, I'm too old for this". Nope. You're just out of condition. Use it or lose it.