In July of 2011, Will Stewart of 3-D Optimal Performance interviewed Dr. Timothy Noakes, a South African exercise physiologist and author of Lore of Running. Noakes recently published Waterlogged: The Serious Problem of Overhydration in Endurance Sports , a book which addresses the little known hazards of drinking too much water, especially for women in endurance sports. The primary subject of this interview is the Central Governor model proposed by Noakes to explain the role of the brain in our experience of fatigue during physical exertion.
Conventional wisdom has told us that fatigue from prolonged exertion comes about through depletion of some sort – depletion of oxygen, depletion of carbohydrates - or a buildup of lactic acid. However, if this were true, distance runners should collapse at the end of a long distance if their stores of oxygen or fuel were depleted. In fact, if they were to run long enough, they should just drop dead. While there have been a few rare instances of that happening, they are very, very rare. Many runners, in spite of their fatigue, will experience a surge of energy as they near the finish line. If their fatigue were due to depletion, they should not be able to have such a surge. In addition, the tendency to feel fatigue commonly occurs no matter what the length of the race. Those who run 10K feel it near the end of their run; those who run marathons feel it near the end of their run. No matter the distance, the sensation of fatigue is common near the end of a run as is the surge of energy when the finish line is in sight. How can this be explained if the sensation of fatigue comes from depletion?
Dr. Noakes proposes that rather than depletion, the feeling of fatigue is generated by the brain as a protective mechanism. He reasons that if the brain allowed the body to push itself to depletion, we would die or come close to dying when we exerted ourselves. This would work against our survival. He believes that the brain creates the sensation of fatigue long before depletion in order to protect the body and that understanding this can help a runner overcome fatigue and improve their performance.
Noakes is a fascinating and engaging speaker. Will Stewart presents a wonderful opportunity for Noakes to freely express his ideas and experiences. I’ve recommended this interview to many runners and they have all told me how much thay have enjoyed it. It will also be of interest to other athletes and anyone who wants to understand exercise physiology or the role of the brain in performance.
Listen to The Brain's Role in Performance: Central Governor Model at 3-D Optimal Performance BlogTalkRadio.