There is an increasing tendency among teenagers all over the world to sleep fewer hours during the week and to make up for it over the weekend. This is already an epidemic in certain Asian countries such as China, Korea and Japan, where young people spend less time sleeping than Europeans or Americans. The immediate consequence is a lower academic and sports performance. The danger is that this is happening during the development stage where lifetime habits are being formed. A teenager who is regularly deprived of hours of sleep will probably turn into an adult with the same habit and will find it difficult to reach full intellectual and physical performance.
This tendency towards irregular sleep has two causes: the changes to our circadian rhythm after reaching adolescence and social jet lag. One aggravating factor is the use of screens and technology, which significantly reduce the amount of time spent resting.
Our body’s circadian rhythm is a cyclical pattern linked to sunlight, which automatically regulates our tendency to feel active or sleepy. As children, we fall naturally into the day/night cycle, since all children are daytime chronotypes. With adolescence comes a readjustment where people begin to fall into either the daytime chronotype (where they are more active in the earlier hours) or the afternoon chronotype (where they are more active in the afternoon). This is when social jet lag occurs, a sleep deprivation caused by the incompatibility between teenagers’ circadian patterns and their social obligations.
Around the world, schools are starting earlier and earlier, forcing teenagers to get up at the crack of dawn, and this particularly affects teens who have an afternoon chronotype. This negative effect has become universal due to technology since it allows people to extend the time spent on social relationships late into the night. Social jet lag develops after sleep deprivation and is so called because its effects are identical to those suffered by international travellers: fatigue, irritability, memory failure and confusion in decision-making.
It has been observed that those teenagers who sleep little during the week tend to spend an excessive amount of time sleeping over the weekend to compensate. However, the resulting feeling of being rested does not eliminate the harmful effects that sleep deprivation has had on their bodies. Academic performance decreases, body mass increases and there is a greater tendency towards feelings of discouragement and, in the most severe cases, depression. If this irregular sleeping pattern is prolonged over time, the cognitive abilities of teenagers are definitively reduced, resulting in a much lower performance than they could have achieved with regular rest.
This phenomenon, reflected in many scientific studies, has also been observed among young people who play sport. People tend to assume that the most basic effect of not sleeping well is muscle fatigue, but specialists have found that when it comes to sporting events, poor sleep also affects cognitive performance. When spatial and reasoning abilities are reduced, it takes more seconds or tenths of a second to understand a game situation or to decide how the play should move forward, thus increasing the risk of making an error. To counteract this and other negative effects, Barça specialists, in conjunction with the AdSalutem Institute and Allianz, have developed a Sleep Guide for adolescent athletes which makes it easier to understand the benefits of sleep, as well a list of habits that can be formed in order to encourage sleep on a regular basis.
These recommendations seek to re-establish the circadian rhythm and to emphasise the tendency to adopt the daytime chronotype using simple techniques. All of these techniques are based on the scientific evidence of how light and darkness influence the body, which results in the production of melatonin, also known as the “sleep hormone”. It also includes every aspect of behaviour, from technology use to food, and it focuses on creating environmental conditions that promote sleep. These recommendations are intended to provide a more effective type of invisible training that can improve the well-being of athletes.
If sleeping well always leads to better performance in all day-to-day aspects of our lives, it would also make a significant difference for adolescents
The Barça Innovation Hub team
*This article is part of a series intended for young athletes and sports staff members. It reveals the latest research on sleep and provides resources to help reinforce or change behaviours. Together with the AdSalutem Institute and Allianz, this is one of Barça Innovation Hub’s attempts to help with this aspect of invisible training and goes hand-in-hand with the Sleep Guide developed for the club’s young athletes.