Walking versus cycling test: Physiological responses in normobaric hypoxia

BACKGROUND: Races that take place in the mountains cover a variety of terrains at several altitudes. Atest for predicting acute mountain sickness has been developed on the basis of a "normal" population but not on the basis of an athlete population. The aim of this study was to compare the Richalet Test to a specific test for athletes. METHODS: Eleven subjects (age: 29.7±8.9 years, VO2peak: 55.7±8.5 mL/kg/min) underwent two incremental tests on a cycle ergometer (CE) and treadmill (TR). Then, they underwent two tests on the CE and TR composed of: 1) five minutes of rest in normoxia; 2) five minutes of rest in hypoxia (fraction of inspired oxygen (11.5%); 3) five minutes of walking or cycling at an intensity of 80% of the respiratory compensation point in hypoxia; and 4) five minutes of rest in normoxia. We compared the following parameters at rest and during exercise: Desaturation, ventilatory and cardiac response. RESULTS: None of the mean values of the investigated parameters differed between the two tests (P>0.05), but some subjects who had out-of-range values on the CEdid not have out-of-range values on the TR(or vice versa). CONCLUSIONS: We showed that there were: 1) no differences in the mean values of the analyzed parameters between the two protocols; and 2) that the responses to the CEand TRprotocols varied across individuals. For individuals who are planning to hike or run at a high altitude they should undergo a walking test. Additionally, when athletes plan to compete at high altitudes, the intensity of the test should be similar to that planned for the race.