Pretty interesting read over at Powering Muscles: 10 Ways to Train Your Brain for Better Performance:
The best evidence that muscle fatigue starts in the brain comes from studies involving sensors that measure electrical activity in the muscles. The amount of electrical activity in the muscles is a direct indicator of how hard the brain is driving them to perform work. In a recent French study, researchers found that an involuntary drop in performance during repeated bicycling sprints was accompanied by a comparable decline in electrical activity in the muscles. These results clearly showed that fatigue was not caused by acid buildup or any other factor within the muscles themselves. Instead, it was caused by reduced drive from the brain.
There is no spoon.
Bonus link: over at Salon a writer decided to give Charles Atlas' 1922 "Dynamic Tension" course a go. You know, the one you saw advertised in comic books as a kid? Pretty funny stuff. Not all crazy (but some very crazy).
