Are you fitter than a Sherpa? Highly unlikely, according to research at UBC Okanagan.
Prof. Chris McNeil and PhD student Luca Ruggiero say their testing using an isometric dynamometer suggests the Sherpas of the Himalayas have specially adapted muscles that give them up to twice the resistance to muscle fatigue of us lowlanders.
“People who live near sea level – lowlanders – struggle with fatigue and impaired physical performance at high altitude, when the oxygen levels are very low,” says McNeil, assistant professor at UBC Okanagan’s School of Health and Exercise Sciences.
“But the Sherpa are born and raised at low-oxygen, and their ancestors have lived above 4,000 metres for 20,000 years, so they are the gold standard of exceptional high-altitude performance.”
McNeil and Ruggiero wanted to know if their muscle fibres are just as efficient in a low-oxygen environment as their well-studied cardio systems.
To test the idea, they travelled to the Pyramid International Laboratory at Mount Everest, where they performed their tests.
“It turns out that the Sherpa fatigued about 33 per cent less than lowlanders and recovered nearly twice as fast," said Ruggiero. “At 5,000 metres, where the oxygen concentration is roughly half that at sea level, the Sherpa out-performed even the fittest lowlanders."
The dynamometer measures the force exerted by the quadriceps. After determining the strength of each participant, electrical stimulation was used to make the quadriceps contract rhythmically, as they do when walking, for approximately four minutes. Muscle fatigue was measured as the drop in force from the start to the end of the four minutes.