I would qualify that with "To a degree". whether or not we concede that nature or nurture is the most predominant factor for the upper potential threshold for a

I would qualify that with "To a degree". whether or not we concede that nature or nurture is the most predominant factor for the upper potential threshold for a persons intelligence, that doesn't really help the person born... as they have control over neither. There are plenty of snake oil companies that have attempted to sell a silver bullet towards being able to increase somebody's fluid intelligence everything from luminosity to hucksters which claim to be able to teach you how to have an eidetic memory, but it's mostly a con. Interesting that you decided to pick athletes because I would argue that genetics play a far larger part in determining one's aptitude for being able to participate at the Olympic level than anything else. Do you think that the 10,000 other diligent athletes that can't even get close to Usain Bolt don't train just as hard as he does? What about the thousands of equally studious physicists who will never get close to a Richard Feynman or an Enrico Fermi? I will grant that through diligence and dedication one can increase one's ability to pattern match to solve certain problems.