@LDRSHIP – my point wasn’t that one group was doing it right and the other wrong, it was that they are basically two different activities that share some basics.
An extreme example might be ice skating. Going to a local rink and skating around doesn’t look anything like modern figure skating. It doesn’t mean one group is doing it right and the other wrong, it’s just two different activities. Figure skating has been optimized into something different. In the same way, people run for sport differently than they run “naturally”. Natural isn’t synonymous with “best” here.
To me, natural running (meaning it comes naturally to us) would generally be for an obvious purpose, include resting when you need to, and generally involve sprinting rather than slogging. It can make people smile. Kids on the playground run because it’s fun, or to chase someone, or to get somewhere quickly. They don’t run at a pace, try to better yesterday’s time, or to burn the calories in their dessert.
Most adults run for exercise and that’s not really any more natural than “I’m going to lift these heavy metal plates repeatedly”. The smiles are in the accomplishment, the exhaustion, or the fact that it’s over.