Sleep is a key process for the restoration and regeneration of the body and mind. During sleep, many important biological processes occur that have a profound effect on our physical and mental well-being. Lack of sleep can have negative effects on overall health and affect the body's ability to regenerate and adapt to new challenges.
- Importance of sleep for metabolism: long-term sleep deprivation can lead to increased food intake and less motivation to exercise, which can cause an increase in adipose tissue;
- Hormonal balance during sleep: during sleep, growth hormone is released, which is important for tissue regeneration. Lack of sleep leads to lower testosterone production and higher production of catabolic hormones such as cortisol;
- Functions of sleep for the nervous system: sleep allows the brain to regenerate and cleanse itself of accumulated waste products. Lack of sleep can reduce cognitive abilities and increase the risk of depression;
- Effect of sleep on the immune system: during sleep, the immune system is stimulated to produce cytokines. Insufficient sleep can weaken the body's defense mechanisms and increase the risk of disease;
- Optimal sleep time: although optimal sleep time can vary, 7-8 hours of sleep per night is recommended with the option of short naps during the day for best recovery and performance.
Effect of sleep deprivation on metabolism
The rate at which we burn the energy in our diet has a direct impact on whether we gain or lose weight.
Studies show that when we sleep poorlyfor long periods of time, we are more likely to be hungry and have a higher appetite, as well as less willpower to exercise. In such cases, energy intake exceeds energy expenditure and leads to the accumulation of fat in human body (1).
Sleep and hormones
One of the most important aspects of sleep that affects recovery is hormonal balance. During sleep, growth hormone is released, which promotes the repair and regeneration of tissues, especially muscle and bone. This hormone is essential for growth and recovery after injury or intense physical exertion.
Quality sleep thus helps muscles recover faster after training and minimizes the risk of injury. Another hormone important for recovery is testosterone, which is secreted in smaller amounts fromlack of sleep. In contrast, catabolic hormones are secreted to a greater extent, leading to muscle breakdown. The most secreted catabolic hormone in sleep deprivation is cortisol (2).
Sleep and the nervous system
During sleep, the brain is given time to rest and cleanse itself of the accumulated waste products that are produced during wakefulness.
Lack of sleep can:
- lead to the accumulation of these "toxins"
In the long term, the risk of depression increases significantly, and cognitive abilities such as memory or learning ability are generally reduced (3).
Sleep and disease
A properly functioning immune system provides constant protection against most viruses,bacteria, and other pathogens in our environment. During sleep, cytokines are produced and released, which activate our immune system and are so important for fighting infections and inflammatory processes in the body.
Lack of sleep can:
- weaken the immune system and increase the risk of disease
So unless we want to drop out of regular workouts due to illness, we shouldn't underestimate the importance of sleep (4).
The importance of sleep for athletes
Sleep is essential for normal functioning and even more important for athletes. There have been dozens of studies in which athletes of all levels have been denied or allowed sleep and then their performance measured.
Athletes with sleep deprivation naturally have
- a deterioration in performance
- a decrease in strength
- a decrase in explosiveness
- a decrease in precision of movements.
On the other hand, sprinters who had to indulge in half an hour of sleep after lunch each day performed better. The basketball players who were ordered to take a 10-hour night rest, which they had to use to sleep, improved in shooting accuracy and court speed after 5 weeks. In another study, tennis players increased their serve accuracy by 6% after a week of sleeping 9 hours each night. Even football players in Australia increased their number of goals scored per season after a 6-week sleep program (5).
How much sleep is needed?
This question cannot be answered by one number.
- Studies show that people perform best after8–11 hours of sleep
- At least 7–8 hours of sleep are needed at night
- Additional time can be slept during the day in the form of short (20–30 minute) "powernaps"
In conclusion, it is clear that sleep plays an irreplaceable role in the process of regeneration of the body and mind. Getting enough quality sleep has a positive effect on hormonal balance, the restoration of energy reserves, immune system functioning, brain and muscle regeneration, and psychological well-being. It is therefore important to pay proper attention to sleep and ensure sufficient sleep duration and quality for optimal recovery and overall health.
Tips for better quality sleep and falling asleep faster
All of us have experienced nights when we lie in bed, thinking, and can't fall asleep. If you want to avoid more of these nights, try following a few simple recommendations.
- Don't consume coffee, black or green tea, or energy drinks in the late afternoon and evening.
- Go to bed at a similar time every day and get up at a similar time; in short, have a regular routine.
- When you lie down in bed, don't stare at screens anymore, but close your eyes, focus on your breathing, and gradually consciously relax the muscles of your face, then your neck, then your torso, then your limbs, down to your fingertips. It is much easier to fall asleep with a completely relaxed body.
- For deeper sleep, try eliminating sources of sound and light in your environment. You may not notice it, but light and noise can reduce the quality of your sleep.
- If you can't fall asleep for an extended period of time, there's no point in lying down and continuing to stare at the ceiling. Try getting up, changing your surroundings for a while, engaging in an activity, and trying to go back to sleep in half an hour.
1) Dattilo, M et al. “Sleep and muscle recovery: endocrinological and molecular basis for a new and promising hypothesis.” Medical hypotheses vol. 77,2 (2011): 220-2. doi:10.1016/j.mehy.2011.04.017
2) Leproult, Rachel, and Eve Van Cauter. “Role of sleep and sleep loss in hormonal release and metabolism.” Endocrine development vol. 17 (2010): 11-21. doi:10.1159/000262524
3) Short, Michelle A, and Michael W L Chee. “Adolescent sleep restriction effects on cognition and mood.” Progress in brain research vol. 246 (2019): 55-71. doi:10.1016/bs.pbr.2019.02.008
4) Besedovsky, Luciana et al. “The Sleep-Immune Crosstalk in Health and Disease.” Physiological reviews vol. 99,3 (2019): 1325-1380. doi:10.1152/physrev.00010.2018
5) Vitale, Kenneth C et al. “Sleep Hygiene for Optimizing Recovery in Athletes: Review and Recommendations.” International journal of sports medicine vol. 40,8 (2019): 535-543. doi:10.1055/a-0905-3103