Ever think that if you could not feel pain, you'd run, bike, swim faster? The idea of not feeling a thing as you physically exert yourself appears to be a grand idea. You may imagine yourself performing at faster speeds, soaring effortlessly. Such an idea........couldn't be farther from the truth.
In 2006, Markus Amann and his colleagues performed an experiment with a pain inhibitor known as fentanyl. During a 5k self-paced time trial, participants were given fentanyl to block afferent feedback. No superhuman performance occurred by any of the cyclists. Instead, the cyclists performed much worse than without taking fentanyl. Because the pain information that comes from the muscles could not be communicated to the brain, they did not know how to manage their pace. Without that feedback, the participants ran like an inexperienced runner, going out crazy and harder, building up a greater degree of peripheral fatigue because the brain had no incentive to control let alone monitor the pacing strategy.
In the second half of the trial, the participants faded tremendously and had trouble walking and standing afterwards. This study showed that pain/afferent feedback is crucial to a good performance. The brain utilizes the amount of pain you experience to ensure that exhaustion occurs at the finish line, not before. When you block pain entirely, you have no way of knowing if you are pushing too hard too soon.
So the next time you're out there training or racing, remember that pain is your friend. It helps you to perform better. Embrace it, welcome it, and harness its power. Pain is like fabric. The stronger it is, the more it's worth.
Be well and run on!