[rorykoehler]

Watching the world record marathon in Berlin in person I would agree about form being the decisive factor. There is a huge middle ground between long time runners and people who don't run at all. That said I know multiple successful long time long distance runners who severely damaged themselves.

I prefer cycling. Running has wrecked me multiple times (100m & 200m training). I'm not built for long distance which is a shame because I could hold pace with the best amateurs over middle distances when fit (sub 3 min kms).