Any sufficiently advanced physical skill is indistinguishable from magic. There is a point at which a virtuoso makes something look simultaneously both so easy and so difficult that it no longer appears to the layperson to be the result of mere practice, but of some mystifying and possibly genuinely God-given gift. Here are some examples:
1) Danny Carey's drumming. I have a love/hate relationship with Tool, but there is no doubting the astounding musicianship and skill of the band's constituent members. In any case, watch him go:
2) Brett Lee bowling at Piers Morgan. I don't know if there is a video on the internet that better illustrates the difference between a professional sportsman and an amateur than this one. Piers Morgan, as loathsome as he is, is not a bad club-level cricketer. Brett Lee, despite being a few years retired and way past his prime when this video was made, makes him look like a toddler.
3) Paco de Lucia. What can one say?
4) The Chaconne from Bach's Partita No. 2. Consider how tiny and unimpressive a violin looks, and then listen to the astonishing sound it produces in the hands of a master. A Martian could only conclude it was imbued with powerful Earthling-magic.
5) I hate Arsenal and Robin van Persie but this goal just looks like a wizard did it. It ought not to be physically possible to generate that much power, pace and accuracy from the position which he does. I don't care if you don't like or have never watched football - just watch the last, slo-mo replay at the very end of the video. It resembles something from a Marvel Superheroes film.
6) Roger and Floyd Mayweather working the mitts. Then Floyd by himself, skipping. This is just somebody practising.
7) I don't have a love/hate relationship with Al Di Meola, just a love-love one. Listen to him messing around with "Norwegian Wood" with Rick Beato: https://youtu.be/tU745UovT2g?t=376
8) You don't need a gym to work out, you know.
In a world in which there was magic, and in which therefore there could be a class of people with no requirement to do serious work at all, what kind of physical feats would they become capable of? The stereotypical D&D wizard is a frail, bookish nerd - Raistlin from the Dragonlance books - but I wonder if in reality they wouldn't be the opposite. A wizard of middling power can charm bands of servants to carry out his every whim, create fool's gold to pay for anything he likes, and is probably mates with a cleric or two who can heal him if ever he gets into trouble. In such circumstances, what excuse would he have not to become absolutely brilliant at boxing, the guitar, cricket and climbing?
Shadowrun had a character class called the "physical adept", which did not exactly replicate this concept, being more of a melee-oriented fighter, but whose title I would like to steal. The D&D physical adept is in truth much wider in scope, and encompasses not merely immense skill in combat, but in any chosen field of excellence.