golfers use to say there was absolutely no place for fitness in pro golf, then tiger came along (of course gary player was a workout freak since the 50’s) and the whole game has changed dramatically.
I have some literature to support my claim when it comes to running. I wonder if Tiger still works out. He has not exactly been lighting it up. Singh does not look like he is hitting the weights or running 5 miles per day either (I could be wrong).
The literature on stretching for improving performance is weak at best (equivocal is the best description). In the case of golfers, increasing range of motion (a different prospect) certainly helps and professionals in the area of PT and Ex Sci were telling that to golfers long ago. They just were not wanting to do it.
I think traditional strength training does little for running. Explosive stuff may help (and I believe it does). That would be Olympic lifts and plyometrics. How many people do those? Most people go to the gym and do exercises that I think are of limited benefit, if any.