Is this true? I mean, I recently discovered that cycling, at least if it involves some climbing, can keep me in reasonable shape for running. So after not having run for about a year, maybe more, I was able to do three runs over a month (11 km, 14 km, 16 km) to prep for a successful 22 km run.
Yet in D&D running would normally be CON, and cycling DEX. And DEX covers everything from balance to deftness to reflexes to speed. So great jugglers are also great high jumpers.
The Athletics skill in 4e and 5e hardly seems like some weird outlier or proud nail in this respect. Especially as, it seems to me, someone who has the strength and endurance for climbing is likely to at least be a passable swimmer.