Originally Posted by
jamesdak
Well I'll be that guy, LOL! I have bad knees but can ride no problems. By bad knees I mean lot and lots of meniscus damage with replacements coming in the next couple of years. I normally spin but am a masher for mountain climbs. As my knees have gotten worse I've had to stay completely out of the mountains. I can still ride my usually 25+ daily rides as long as I don't mash. If I do my knees will swell and become so painful I can't hardly walk. So yeah, put me in the camp of mashing is bad for you. I'd bet even if you do "get away with it" and feel no effects currently it will effect you as you age. Just my two cents....
I don't doubt that once your knee is injured, then mashing will be harder than if it is not. But notice that your anecdote says you developed these knee problems while you were primarily a spinner.
What it comes down to is a certain percentage of people will screw their knees up regardless of whether they ride or not, and also regardless of spin vs. mash. These threads always end up with people telling me that even though they got some sort of joint problems without significant mashing habits, that somehow indicates that mashing is bad for you, and that they know someone who mashed and their knee went bad. We all know plenty of people with bad knees as we get older, but did you ever notice how many of them DIDN'T mash high gears?