Sleep is a metabolic process that has an important role in body cells and brain cognitive function. In a review article conducted by Fullagar et al. (2014), the function of sleep on body cells, including restoring the immune system and hormones, providing a resting effect on the nervous system, and increasing metabolic function when we wake up. As for the cognitive function of the brain, Fullagar et al. explained that sleep increases the capacity to think, remember, and learn something new. In terms of sports performance, sleep can maintain and increase the capacity of strength, aerobics, and endurance during exercise. Apart from the benefits mentioned above, sleep also plays an important role in the resting process of muscle cells which is useful for muscle protein synthesis.
Knowing the many uses of sleep for our bodies, it is unfortunate that there are still so many individuals who consider sleep as a trivial thing. This has an impact that adequate quality and amount of sleep is not a priority for everyone. The question is, how many hours of sleep is needed to ensure sports performance is not compensated? So what happens to sports performance when a person is sleep deprived?
In general, the recommended sleep duration ranges from 7-9 hours, which can be applied monophasically (one sleep at night) or biphasic (sleep twice, during the day and at night). In the book “Why we sleep”, Matthew Walker explains, adults and the elderly have a need for sleep ranging from 7-8 hours. Walker (2017) explains that apart from duration, the body also has a biological wake-sleep cycle known as the Circadian Rhythm, which changes with age. Adults, for example, have a sleep rhythm from 11 pm to 7 am the next day. In contrast, for the elderly, this population has a sleep rhythm from 9 pm to 5 am the next day. Walker explained that the general perception that older people have less need for sleep is not true.
Lack of sleep
The impact of sleep deprivation has often been studied both in terms of sports performance, work, or activities the next day. In general, sleep deprivation can be categorized as chronic, ie if a person stays awake for up to 36 hours. In addition to chronic, individuals can also be categorized as sleep deprived if they lose 3-4 hours of their sleep needs. Fullagar et al. (2014) mentions the impact that occurs when a person experiences chronic sleep deprivation or loses 3 hours of their total sleep needs, including:
- Decrease in aerobic performance 10-20%.
- Feeling easily tired during exercise.
- Decreased performance during strength and endurance training.
- Decreased performance in sports that require skill and accuracy, such as tennis, badminton, volleyball, or similar sports.
- Decreased maximal muscle strength, such as lifting weights.
- Increased energy use so that exercise effort is not commensurate with the energy used.
- Changes in the capacity to use carbohydrates, which results in decreased tolerance of the body to glucose; in other words, the body cannot properly use glucose as an energy source.
Sleep Enough for Exercise
When you are an active individual in sports, be it strength, endurance, or aerobic exercise, make sure you get enough sleep at night before you exercise. As a fitness trainer (PT), it is important to always encourage your clients to get enough sleep before training sessions take place. Do not hesitate to change the exercise program that you have compiled, when your client comes in a sleepy state due to lack of sleep at night. For an athlete, getting enough sleep before a competition is very important, especially for athletes who need skill and accuracy in their matches.