The Science of the Climb

Research on McKinley

The major effect of high altitude upon human physiology is a decrease in oxygen pressure and content in the arterial blood. The atmosphere at high altitude contains the same percentage of oxygen, 20.93%, as at sea level, but the partial pressure is reduced. It is the partial pressure that drives oxygen from the lungs into the blood. At 5,850m the atmospheric pressure is about half that of sea level. At 8,500m it is only about one-third that of sea level. Symptoms of high altitude discomfort usually begin above 2,600m and become more severe the higher the altitude and the more rapid the ascent.

Travel to high altitude results in the development of some of the symptoms of acute mountain sickness (AMS) such as headache, malaise, nausea, and fatigue, any of which can become disabling to a climber, and may require either supplemental oxygen or descent from altitude. The severity of AMS symptoms depends on the altitude attained, ascent rate and individual factors such as fitness, exercise, sleep, and diet. One of the challenges facing altitude physiologists today is the elucidation of these and other components that may predict susceptibility to AMS and associated extreme altitude conditions. During the climb on Mount McKinley, expedition members will conduct a series of cardiorespiratory studies designed to advance the understanding of the physiological responses that determine performance in extreme cold at high altitude.

The study will examine the physiological responses of endurance trained athletes during exposure to extreme cold and altitude. Given the inclusion of female expedition members it will also be possible to compare between-gender differences and identify possible predictive markers for AMS susceptibility. Few studies have been made of the physiological responses of women to high altitude compared with those of men. Even fewer have examined the relationship between endurance performance characteristics and gender. Given the unique responses of women and endurance-trained athletes at altitude it is predicted that the results of this study will advance the understanding of cardiorespiratory responses to acute altitude exposure and provide background data which will permit similar studies to be performed.

High altitude research at SFU

Established in September of 1997, the Aerospace Physiology Laboratory in the School of Kinesiology at Simon Fraser University is equipped for a wide range of human physiological testing. The Aerospace Physiology Laboratory is integrated via computer (audio, video, data) with the Environmental Physiology Unit (EPU, est. 1981). The EPU features a dive/altitude chamber complex with an altitude capability of 33.5km (equivalent to Mars atmospheric pressure) that has living quarters for four with life support. This combined Environmental and Aerospace Physiology Laboratory is the only comprehensive environmental research facility of its kind at a Canadian university.

The facility extends Canadian science capabilities into research related to high altitude physiology and extreme cold. The Laboratory provides world-class scientific and technical training that is perfect for conducting the high altitude and cold weather research associated with the climb up Mount McKinley, and ultimately to 8,000 meter peaks.

In April and May 2000, the SFU Aerospace Physiology Team, directed by Dr. Andrew Blaber, is embarking upon an innovative combined research and educational program focussing on the physiological responses of female and male endurance athletes during exposure to extreme cold and altitude. The program includes a series of preliminary tests conducted in the altitude physiology laboratory located at SFU, followed by field research performed while climbing the West Buttress Route of North America's highest (and coldest) mountain, Mount McKinley (6,194m).

In order to generate community interest and excitement in this research, the SFU team will transmit data together with daily reports and images via INMARSAT satellite link to both university researchers and students, as well as to local elementary and high schools in the Greater Vancouver Regional District.

The Future

This expedition to Mount McKinley will be the first of three related research projects investigating the effects of extreme cold and altitude upon endurance athletes.

In the pre-monsoon period of 2001 (April, May) the same climbing team will climb Cho Oyu, the world's sixth highest peak (8,201m) located in the Khumbu region of East Nepal. December 2001/January 2002 is the time-slot for the team's final objective, 4,897m Mount Vinson, the highest mountain on the continent of Antarctica.

While the McKinley expedition will characterize the responses in a combined high altitude and extreme cold environment, the purpose of the Cho Oyu climb will be to identify responses at extreme altitude. In order to define responses across the whole spectrum of what represents the extremes of cold and altitude, the Mount Vinson expedition will focus primarily upon the effects of extreme cold.