The only possible devil's advocate explanation I could come up with for this, would be if someone is very active, like they love to go mountain biking on actual mountains, so they need athletic friends to share that with. But that's pretty much the only sort of situation where it makes any sense.

The highest I ever really crank my athleticism is relaxing walks or dancing around when I'm by myself. I would rather have a beer and watch Metalocalypse than try to bike a damned mountain. All I need a friend to have is my weird sense of humor, a good heart and a chill personality. No physical package requirements over here lol.