Sleep, exercise and hypoxia: How an altitude deployment creates unexpected risks

Abstracts / Journal of Science and Medicine in Sport 20S (2017) S44–S46 S45SE was positively correlated to the amount of physical activitythe day before. During the Antarctic deployment at moderate altitude(3800 m), hypoxia triggered sleep-disordered breathing whichshowed no acclimatization over the entire year, and which wasnegatively affected by exercise. The extent to which individualswere affected by hypoxia showed a large interindividual variability,suggesting the existence of responders and non-responders.The intervention study confirmed the deleterious effect of exerciseon sleep-disordered breathing in hypoxia.Conclusions: The current attitude to medical risk assessmentassociated with altitude is dominated by the acute mountainsickness (AMS), high altitude cerebral oedema (HACE) and highaltitude pulmonary oedema (HAPE). These are considered featuresof acute exposure during the acclimatization period. However, wereport a risk that is less dramatic, occurs at lower altitude, forlonger duration, and may have lasting implications for the individual.Soldiers are expected to continue their exercise regimen ondeployment, however, this may have a deleterious effect throughsleep-disordered breathing, even at moderate altitude. Several currentdeployment locations in Central Asia and in the Middle Eastinvolve this risk for deployed personnel.