Dean suffers from a condition which clears the lactate buildup in his body at a very fast rate as compared to other runners.
Every athlete has a limit. Scientifically, this limit is defined as the body’s lactate threshold and when you exercise beyond it, running rapidly becomes unpleasant. We’ve all experienced that burning feeling – heart pounding, lungs gasping for air – as your muscles begin to fatigue, eventually locking up altogether as your body shuts down. However, there is one man whose physiological performance defies all convention: Dean Karnazes is an ultrarunner from California and, at times, it seems as if he can run for ever.
Karnazes has completed some of the toughest endurance events on the planet, from a marathon to the South Pole in temperatures of -25C to the legendary Marathon des Sables, but in his entire life he has never experienced any form of muscle burn or cramp, even during runs exceeding 100 miles. It means his only limits are in the mind.
“At a certain level of intensity, I do feel like I can go a long way without tiring,” he says. “No matter how hard I push, my muscles never seize up. That’s kind of a nice thing if I plan to run a long way.”
“To be honest, what eventually happens is that I get sleepy. I’ve run through three nights without sleep and the third night of sleepless running was a bit psychotic. I actually experienced bouts of ‘sleep running’, where I was falling asleep while in motion, and I just willed myself to keep going.”
While years of running can help to improve an athlete’s lactic acid threshold, Karnazes’ abilities come from his unique, innate ability to flush his body during exercise.
He also believes that his very low body fat, and his high alkaline, paleo-style diet also helps his superhuman running skills.
Karnazes, who regularly runs the equivalent of a marathon before breakfast, said his focus is always on endurance.
‘I don’t care how fast I go,’ he told IE. ‘I care about how far I go.’