Fulco, C. S., Muza, S. R., Beidleman, B., Jones, J., Lammi, E., Kambis, K., Doan, B. K., Brothers, M. D., Zupan, M. F., & Cymerman, A. (2008). Living for six days at 2,200 m improves prolonged time-trial performance of sea-level residents exposed to 4,300 m. ACSM 55th Annual Meeting Indianapolis, Presentation Number, 1273.

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"It is well established that the magnitude of the initial impairment in prolonged time-trial performance that occurs when sea-level residents ascend rapidly to high altitude (e.g., 4,300 m) is attenuated with acclimatization to the same elevation. Whether adaptations acquired from living temporarily at a moderate altitude (“staging”) just prior to the high altitude exposure will also benefit time-trial performance is less certain."

This study evaluated the effectiveness of staging at 2,200 m on time-trial performance of sea-level residents during subsequent exposure to 4,300 m. Healthy men (N = 10) were tested on a cycle ergometer during steady-state exercise and then during a maximum effort time-trial at sea level, and again within three hours of introduction to 4,300 m pre- and post-staging for six days at 2,200 m. Before and after pre-staging, steady-state exercise was performed for 20 minutes at low and moderate power outputs to assess adaptation.

At 4,300m, comparison of pre- and post-staging values showed arterial oxygen saturation increased during low steady state exercise while heart rate and ratings of perceived exertion decreased during moderate steady state exercise. Time-trial duration increased and power output was higher after staging. Time-trial performance of all 10 Ss improved pre- to post-staging (range: 2 to 56 min) with the extent of each individual’s improvement being directly related to their increase in arterial oxygen saturation during steady state exercise and the time trial.

Implication. The impairment in prolonged time trial performance of sea level residents rapidly exposed to 4,300 m was reduced after living for six days at the moderate altitude of 2,200 m. The close association between improved time-trial performance and higher exercise arterial oxygen saturation suggests the major contributing factor was increased ventilation.

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