Running overwhelmingly dominates as the sport that utilizes the cardiopulmonary system the most
Marathon requires continuous non-stop completion without time to rest
When you go Gran Fondo, you ride for a bit, then stop at aid stations to eat, smoke, and chat, so you start questioning if this is really exercise
Running experts naturally become good cyclists
Even if they don't cycle as well as their running ability, it's just unfamiliarity with bikes, not inferior athletic ability whatsoever
-> Nobody thinks Yui, who is excellent at swimming and running, has inferior athletic ability just because she's relatively worse at cycling
And since cycling itself, like racket sports, uses tools to propel forward, it absorbs a considerable amount of physical handicaps
-> You rarely see out-of-shape middle-aged men in marathons, but you often see them in Gran Fondo
-> Nobody thinks an out-of-shape middle-aged man has superior athletic ability just because he plays golf well (they only think he plays golf well -> this is exactly the limitation of tool-based sports)
Most running experts do well when they go trail running.
There are occasional cases where sub-3 marathon runners who couldn't break the barrier switch to trail running and then cosplay as experts (if a sub-3 runner properly does trail, they'd be fast).
Mountain climbing is also done with your own body so it's closer to the essence of exercise than cycling, but since climbers also rest midway, drink makgeolli, and play in stream water, compared to running it moves away from the essence of exercise
Rather than dabbling in various sports half-heartedly, if you properly focus on running alone, the rest (trail running, mountain climbing, cycling, etc.) naturally follow
