We read with great interest the article titled ‘Cerebral Water and Ion Balance Remains Stable When Humans Are Exposed to Acute Hypoxic Exercise’ by Avnstorp et al. in Volume 16 of 2015. The authors mention that one of the aims of their study was to investigate the hypothesis that cerebral ions and plasma shifts during a short duration intense bout of exercise in hypoxia are of potential importance to the development of AMS. Though the authors conclude that cerebral water and ion balance remained stable during the 30 minute period of exhaustive exercise, the authors did not attempt to study the actual occurrence of AMS symptoms, acknowledging as a limitation that the time duration was too short for AMS to develop.
We are of the opinion that the authors could have continued the hypoxia exposure for a few hours post exercise and monitored the subjects for features of AMS. It would have been better still if the study had two groups of subjects, both exposed to acute hypoxia, with one group subjected to intense exhaustive exercise and the other remaining at rest, and both groups studied for cerebral water and ion balance and monitored for features of AMS using a sufficiently long hypoxia exposure. The data generated from such a study would probably have given a more comprehensive insight to our understanding of the pathophysiology of AMS.
