What I Talk About When I Talk About Running (走ることについて語るときに僕の語ること, Hashiru Koto ni Tsuite Kataru …
If you're a long-distance runner who trains hard every day, your knees are your weak point. Every time your feet hit the ground when you run, it's a shock equivalent to three times your weight, and this repeats itself perhaps over ten thousand times a day. With the hard concrete surface of the road meeting this ridiculous amount of weight (granted, there's the cushioning of the shoes between them), your knees silently endure all this endless pounding. If you think of this (and I admit it's something I don't usually think about), it would seem strange if you didn't have a problem with your knees.
— What I Talk About When I Talk About Running by Haruki Murakami (Page 88)
Ugh, why are you going to say things that are not based on evidence or science. It’s almost proven at this point that running can strengthen your knees and helps prevent osteoporosis.
PERHAPS based on your stories in this book, you were overtraining? Running an ultra marathon without proper training and then being surprised you deal with injuries shouldn’t be a surprising result.
Specifically quoting this because this section bugged me a lot.