Myths and realities of micro-sleeps

The ultimate and combined consequence of all these effects is a state where the runner can no longer stay awake: it's as if the brain continuously tends to shut down on its own. The individual becomes dazed, immediately tends to fall asleep, and starts dreaming as soon as what's left of their attention catches a fixed stimulus, like the beam of their own headlamp. Continuing becomes extremely difficult: our hero tries to sing, talk to themselves, even slap themselves. It's all in vain. They remain there, sometimes in the grip of hallucinations.

To avoid finding themselves in these situations, the solution often spontaneously resorted to is precisely the micro-sleep: organizing oneself to have short stops where a few minutes of sleep are taken. But does the micro-sleep "work"? Does it genuinely improve the subject's situation, or is it just self-suggestion? And what happens in the brain when we enter micro-sleep?

There is a very interesting study that helps us understand how the use of micro-sleep probably has a real basis in our neurophysiological functioning. A study evaluated the encephalographic quality of sleep in a subject who had walked 338 miles in a state of partial sleep deprivation. What is striking is that as soon as the subject goes to bed, there is a rapid entry into the Slow Wave Sleep (SWS) phase. Slow Wave Sleep is a term used to indicate deep sleep. In this phase, the brain's metabolic activity is reduced, and the brain records the lowest consumption of oxygen and glucose. James Horne, a British researcher and author of a famous book on sleep, argues that unlike voluntary muscles, the brain cannot relax or slow down its activity during wakefulness. So, as long as brain activity is not slowed down, the brain cannot engage in repair and revision activities. The purpose of the SWS phase is precisely to allow such activities. The surprising discovery in the study of the walker in partial sleep deprivation is this: if the sleep space is reduced and compressed into small, more or less frequent intervals, the body organizes itself to optimize times. It establishes priorities and immediately enters the phase that is most important for survival, deferring less fundamental phases in the short term, such as those related to the consolidation of learning and memories.

The strategy of micro-sleeps, therefore, has a real validity; it is rooted in the self-organizing abilities of the brain system, which is capable, in order to ensure survival and a minimum of basic functioning, of changing its way of sleeping by adapting to short intervals of sleep. These intervals – in my direct experience or related to the observation of others' experiences – have an optimal duration if they are between 20 and 40 minutes. However, be careful not to lose the sense of limitation: it is still an emergency strategy. Unfortunately, it seems that, despite what is said, humans are not made to go without sleep.

On this note, I would like to mention a study promoted by the Research Center on Human Performance (CERISM) and the Department of Neurosciences at the University of Verona that will take place at Tor450. The study aims to investigate the effects of sleep deprivation and stress on cognitive abilities in athletes over 50, to understand whether it is true that an older athlete handles difficulties and stress better. It seems so, but I'll tell you more about it another time.

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