There is no such thing as ‘natural running’. It is just a term concocted by those who want to suck the gullible into believing that the running technique that they are promoting is more natural, therefore better for you.

There are several flaws with the concept. The more people appeal to ‘nature’ and ‘natural’, the more likely there is less evidence for it so they appeal to nature and people belief that  ’natural’ is better.

This is a well-known logical fallacy. Just because something is natural does not means it better for you. There are plenty of natural things that are bad for you, such a arsenic and too much ultraviolet light. So natural is not automatically better for you, so to claims that something is better for you is natural is a logical fallacy.

That does not mean that what is being argued for is good for you or not, it just means that you cannot appeal to “nature” to argue that it is.

Evangelists for many different running techniques use the natural fallacy.