The 6-Minute Walk Test as a Predictor of Summit Success on Denali

Objective To test whether the 6-minute walk test (6MWT), including postexercise vital sign measurements and distance walked, predicts summit success on Denali, AK. Methods This was a prospective observational study of healthy volunteers between the ages of 18 and 65 years who had been at 4267 m for less than 24 hours on Denali. Physiologic measurements were made after the 6MWT. Subjects then attempted to summit at their own pace and, at the time of descent, completed a Lake Louise Acute Mountain Sickness Questionnaire and reported maximum elevation reached. Results One hundred twenty-one participants enrolled in the study. Data were collected on 111 subjects (92% response rate), of whom 60% summited. On univariate analysis, there was no association between any postexercise vital sign and summit success. Specifically, there was no significant difference in the mean postexercise peripheral oxygen saturation (Sp o2 ) between summiters (75%) and nonsummiters (74%; 95% CI, –3 to 1; P = .37). The distance a subject walked in 6 minutes (6MWTD) was longer in summiters (617 m) compared with nonsummiters (560 m; 95% CI, 7.6 to 106; P = .02). However, this significance was not maintained on a multivariate analysis performed to control for age, sex, and guide status ( P = .08), leading to the conclusion that 6MWTD was not a robust predictor of summit success. Conclusions This study did not show a correlation between postexercise oxygen saturation or 6MWTD and summit success on Denali.