Objectives: Acclimatization strategies have been shown to be the best solutions to avoid acute mountain sickness. In this context, we have designed a protocol performed in hypoxia that includes resistance routines in combination with classical endurance training exercises with mountain trekking at mid altitude.
Methods: Thirty-two volunteers preparing different mountain expeditions participated in the study distributed into two groups. One group trained at 2000 m, while another group trained at 4500-5800 m of simulated altitude in a hypoxic chamber. Acute mountain sickness was monitored by answering the Lake Louise Scale questionnaire during 2 sleeping sessions at 4800 m of simulated altitude at the beginning and at the end of the study. At the same time, oxygen saturation was determined in both groups to monitor physiologic adaptation. Data were also collected from the base camps in each expedition before ascension.
Results: Acute mountain sickness incidence in the hypoxic group decreased from 100% at the beginning to 12% of individuals at the end of the training period, and it was 25% at the base camps of expeditions. On the other hand, the control group passed from 100% to 88% of individuals at the end of the intervention and 70% at the base camps. At the same time, acute mountain sickness severity was mild in the experimental group compared to moderate-severe in the control group. These data were supported by the oxygen saturation values, indicating adequate adaptation changes for altitude in the hypoxic group.
Conclusion: The inclusion of resistance workouts in combination with endurance exercises, all performed in hypoxic conditions, does not interfere with an optimal adaptation to altitude and to prevent acute mountain sickness.
Keywords: Acute mountain sickness; altitude acclimatization; intermittent hypoxia; mountain expeditions; resistance-endurance training.