At the Peak
Study leader Beidleman explains that the U.S. Army Research Institute of Environmental Medicine's stated mission is to improve health and performance of the Warfighter when exposed to extreme environments. That includes heat and cold, as well as extreme altitude, Beidleman's own area of expertise.
Years ago, researchers showed that staging for four days cut the prevalence of AMS by about half. However, Beidleman says, researchers had never studied whether this time could be trimmed down even further.
To investigate, she and her colleagues studied male soldiers ascending Pike's Peak in Colorado, the summit of which stands at 4,302 meters above sea level. They assigned 12 of these soldiers to stage for two days at 2500 meters. Another seven soldiers staged for two days at 3000 meters. Seven more ascended directly to the peak.
Trimming AMS by Half
Their findings showed that about 73 percent of soldiers who took a direct route to the peak showed symptoms of AMS. However, only 30 to 40 percent of those who staged for two days ended up with this condition, regardless of their staging height.
"These results suggest that you don't have to stay at a moderate altitude for four days. You can stay there for two days and reap the same benefits," Beidleman says.
She explains that two days is enough time for the body to begin affecting the biological changes necessary to live comfortably at a higher altitude. Within hours to days, she says, climbers begin to breathe faster and reduce blood plasma volume which helps the body bring more oxygen to cells, she says. These immediate changes help cells survive until the body implements more long-term changes, such as increasing the number of red blood cells and other metabolic changes.
"The military is always looking for faster, more effective solutions to problems," she says. "Now we know that ou
|Contact: Donna Krupa|
American Physiological Society