22 December 2025
Bilbao Campus
The “Pedro Fabro” Retired Staff Association of the University of Deusto held the third session of its lecture series “Adding Life to Our Years” on 4 December. On this occasion, the speaker Arkaitz Larrinaga discussed “The relationship between sleep, rest and physical activity,” a talk he summarised with the motto “Dreaming of Sleep.”
In his presentation, he discussed the characteristics of sleep, recommended sleep durations, the history of sleep, sleep stages and patterns, concluding with the importance of physical activity and sleep. During his talk, the expert explained that sleep is divided into several REM and non-REM cycles, with REM making up approximately 25% of sleep, and non-REM including the stages of drowsiness, physical rest, light sleep, and deep sleep (about 30 minutes).
As he explained, during the REM phase the brain is active and dreams occur; “it is essential for learning and emotional memory.” In deep sleep, the body undergoes repair and memories are consolidated. In this sense, sleep is a vital, complex, active, and cyclical process. A reduction in sleep leads to psychological, behavioural, and physiological disturbances due to a lack of energy.
Therefore, the quality and efficiency of sleep are important: time spent asleep should exceed 82%. “Sleep recommendations depend on age: for an adult over 65, it should be between 7 and 8 hours. Sleeping is a learned skill: sleep should be improved through movement, and it must be remembered that it is an active process essential for our health and daily well-being,” he emphasised.
Professor Larrinaga explained that neurophysiological and cardiorespiratory variables, as well as sleep stages, can be measured using polysomnography in a hospital setting and daily with smart watches (actigraphy). Sleep–wake cycles depend on many structures primarily located in the central nervous system. It is important to emphasise that activity and sleep are intrinsically linked.
In his view, regular physical exercise provides various health benefits, including better sleep quality and fewer sleep disorders. However, intense exercise in the evening can disrupt sleep due to increased activation. According to recent studies, the most effective activity is high-intensity strength training in intervals, lasting 30 minutes, one to two days per week.
