Sleep and performance at high altitude - discovering what happens to the brain

A third of the earth is above 1,000m and 10% between 2,000 and 4,000m above sea level. Scientific research and athletes are demonstrating that it's possible to practise sport at high altitude and that the quality of life at these altitudes can be improved.

The main difficulty of life at high altitude is due to the diminished barometric pressure which means less oxygen pressure in inrooted gases. The principal effect of this situation (hypoxy) is reduced work capacity caused by the diminished possibility of utilizing aerobic metabolic processes to resynthesize energy (APT) for vital activity, work and exercise.

The tissue that suffers most in hypoxy is the central nervous system, which provokes a reduction in neuron excitability and alteration of the sleep pattern.

 The research carried out in Tibet during the Everest SkyMarathon demonstrates the correlation between variations in the heart rate with oxygen saturation and the alterations of electrocortical activity. Permanent pathologies due to sports activity at high altitude were excluded.

An indubitable effect of acute hypoxy was verified on the electroencefalografic (EEG) chart without distinction of the sport practised or in sedentary cases. Not only, but after the marathon at 4,350m altitude, certain brain activities could also be superimposed on those verified at sea level after similar exercise.

The second research study investigated alterations in the sleep-wake cycle. It's noted that the quality of sleep can modify both physical and intellectual performance and many researchers agree that unacclimatized individuals at high altitude present a reduction of phases 3 and 4 of the sleep pattern and REM sleep.

These studies were developed by the Peak Performance Project researchers in collaboration with the physiological and sleep research group led by Dr Renato Calcaterra, Dr Ivana Gritti and Prof Maurizio Mariotti of the Università degli Studi di Milano.


Updated: 02 January 2007