I'll give my anecdotal 2cents...I've been strength training since age 11 with no injuries until about 10 years ago (age 42ish or thereabouts) when I decided to go on a super-heavy squat routine. Very quickly the strength of my leg muscles outstripped the ability of my tendons, cartilage etc. to support the weights I was pushing and within a few months I 'blew out' both knees to the point to where walking was painful and more often than not I was wearing some sort of compression knee support to keep the pain under control. Being pig-headed, i did not go to any kind of physical therapy either, so this condition more or less lasted until age 49 when I began cycling. Now, nearly two years later (5200 miles in 2015 and 1700 so far in 2016) both knees are more or less pain free, with an occasional twinge every now and then if I step wrong or do a little too much climbing in one week.

Keith