That's kind of the consensus modern psychology and trainers are coming to. Some kids just have a drive that others don't, and that is what determines how well they do.

The major difficulty with the idea of "natural talent" is that every time someone points to a skill/whatever and says, "this is natural talent" someone else finds a way to teach that skill. Here is one paper: http://talentdevelop.com/articles/ITROM.html

So if you trained hard enough you could run the 100m as fast as Bolt?

"Body shape" isn't what people usually mean by 'talent', and I doubt you define it that way either; but if you want to define talent to mean body shape, I will happily concede that talent is important.

Merriam Webster defines talent as a special ability that allows someone to do something well. I agree with that definition. Usain Bolt is a naturally talented runner.

You said

>The major difficulty with the idea of "natural talent" is that every time someone points to a skill/whatever and says, "this is natural talent" someone else finds a way to teach that skill.

Can anyone be trained to run as fast as Bolt or would they have to be naturally talented in the first place to be trainable?

> "Body shape" isn't what people usually mean by 'talent'

"Talent" is usually a catch-all for innate features distinct from trained features. ("Body shape" has both innate and trained elements.)