Physiological profile of world-record-holder Sherpas

Tibetans and Sherpas have long been revered for their physical aptitude at high altitude, and are thought to have lived at high altitude longer than any other culture. We performed physiologic testing on 2 Sherpas who currently hold world records for: (1) most number of ascents of Mt Everest and (2) speed ascent of Mt Everest from base camp to the summit. In doing so, we describe certain physiological aspects of these individuals that may contribute to their abilities at altitude.

Anthropometric measurements, blood testing, and electro- and echocardiographic examination as well as pulmonary function tests were performed. Exercise testing consisted of treadmill climbing at increasing incline and speed while wearing a 22 kg backpack in Salt Lake City (1325 m) and Park City (2063 m).

Anthropometry, electrocardiography, pulmonary function, strength, and echocardiography were consistent with predicted parameters for the general population. The Sherpas demonstrated appropriate cardiopulmonary response to dynamic exercise similar to moderately fit individuals while performing treadmill testing, both at moderate and high altitude. As expected, the energetic cost increased at higher altitude, likely due to increased respiratory work.

The 2 world-record Sherpa climbers were within normal ranges for the specific measurements that were tested. They displayed appropriate cardiopulmonary and physiological responses and exercise performance profiles at moderate and high altitude.