Just my personal experience. My knees can't do 50+ mpw marathon training anymore. I've backed it down to 30 easy mpw for the last 2 years. Zero speedwork. Very few long runs. But, I'm cycling (mostly indoors, and on a properly set-up dinosaur spin bike) 200-300 mpw. About 50-50 junk miles/quality. I ran my 41st marathon last month, and easily ran my 10th BQ. There's no way in hell I could do that on the running I'm doing.

---

Athlinks / Strava