I doubt pasta or a bad nights sleep would be such an incredible difference to your performance that you might be considered an athlete one day and a couch potato the next.
sigh So far, you've done little more than compare with a completely different form of measurement. Nice timing on that.
Here you might find a chart that shows the differences between IQ ranges. You might notice how you could be 10+/- and manage to find yourself in a completely different range: http://en.wikipedia.org/wiki/IQ_reference_chart
A personal favorite: A 2006 paper argues that mainstream contemporary test analysis does not reflect substantial recent developments in the field and "bears an uncanny resemblance to the psychometric state of the art as it existed in the 1950s."
In other words: fooey.
Successful 90 average entrepreneurs invent, evolve and innovate while there are 110+ middle-aged "geniuses" living in parent's basements. Of course, the opposite is also true.
An IQ test doesn't reflect who you'll be, if you'll be successful or if you'll change the world.
"There is often a stark gap between the abilities of the gifted individual and his or her actual accomplishments. Many gifted students will perform extremely well on standardized or reasoning tests, only to fail a class exam."
To me, IQ is about as accurate as BMI.
http://en.wikipedia.org/wiki/IQ_reference_chart
On a good day, you might be an average IQ. Or a low average. Or a High average.
I think the 100m is a cute analogy, but it falls short. An IQ changes with very little effort; qualifying for a 100m sprint takes a lot of effort: http://www.askmehelpdesk.com/track-field/training-qualify-10....
I doubt pasta or a bad nights sleep would be such an incredible difference to your performance that you might be considered an athlete one day and a couch potato the next.