Load carriage increases arterial haemoglobin oxygen saturation during inclined treadmill walking in hypoxia

Acute mountain sickness (AMS) in its benign form is a relatively common debilitating and self-limiting condition that usually resolves within a few days (Basnyat and Murdoch, 2003). The incidence of AMS continues to increase in concert with the growing number of sojourners to moderate altitude. For example Murdoch (1995a) observed AMS in 160 (57%) of 283 hikers walking the Mount Everest base camp trek in the Nepal Himalaya reaching peak altitudes of »5545 m. Furthermore, many destinations can now be rapidly accessed by air enabling people to fly directly to altitudes in excess of 3500 m, resulting in an increased incidence of AMS; for example 97 (84%) of 116 individuals who flew directly to 3740 m developed AMS compared to 22 (61%) of 38 who walked from elevation