4 positive impacts of sleep on physical performance – 05/03/2023 – Equilibrium

When we ask ourselves what makes a great athlete, few people would imagine that sleep can play an important role.

But many of the world’s top athletes claim that sleep is an essential part of their training routine — and the key to helping them perform.

Serena Williams, for example, strives to get eight hours of sleep a night. NBA star LeBron James aims for eight to 10 hours of sleep, while football legend Tom Brady says he goes to bed early and gets at least nine hours of sleep.

No wonder, as sleep plays a key role in metabolism, tissue growth and repair (such as our muscles) and ensures that memory, reaction time and decision-making function optimally. All these processes impact sports performance.

But it’s not just athletes’ performance that can benefit from an adequate night’s sleep.

Even amateur gym-goers can maximize the fitness and health benefits of working out by getting enough sleep each night.

Here are some ways sleep improves your fitness:

AEROBIC CAPACITY

Exercise is great for improving aerobic fitness. It improves both aerobic capacity (being able to run or cycle faster with a heavier load) and efficiency (meaning your body requires less oxygen to run or cycle at the same pace).

One factor that contributes to improving aerobic capacity is the function of mitochondria in the body.

Mitochondria are small structures within muscle cells that are responsible for generating the energy the muscle requires during exercise.

Research shows that poor sleep (just four hours a night for five nights) can reduce mitochondrial function in healthy people.

High-intensity interval training has been shown to alleviate these deficiencies in the short term (over a five-day period).

However, it is currently unclear how these impairments would influence long-term exercise adaptations.

So it’s best to get a good night’s sleep if one of your goals is to improve your aerobic capacity.

MUSCLE GROWTH

Sleep is also important if you want to build strength or muscle.

Muscle growth occurs when new proteins are added to the muscle structure — a process known as “muscle protein synthesis”.

This process is stimulated by exercise and food intake (specifically protein) and can last for at least 24 hours after training.

Research shows that even a few nights of insufficient sleep reduce the response of muscle protein synthesis to nutrient intake.

This suggests that poor sleep can make it harder for the body to gain muscle mass.

ANABOLIC HORMONES

Hormones act as chemical messengers that contribute to a range of functions throughout the body, such as tissue growth and development.

The hormones that are involved in these building processes can be called “anabolic” hormones.

Two anabolic hormones—testosterone and growth hormone, which are released during sleep—may also be important for recovery and adaptation to exercise.

These hormones play various roles in the body and are related to better body composition (less body fat and more muscle mass).

More muscle mass and less body fat can be beneficial for exercise and health.

When sleep is restricted to just five hours a night (amount of sleep similar to that of many working adults), testosterone levels are reduced in healthy young men.

Restricting sleep of similar duration also alters growth hormone release while we sleep.

While more research is needed, the possibility exists that these hormones play a role in mediating the relationship between sleep and fitness, due to their relationship with better body composition.

REFUELING AFTER EXERCISE

Exercise usually uses glucose (sugar) as a fuel source. Muscles store glucose from the food we eat in the form of glycogen to meet the demands of exercise.

Replenishing glycogen stores after exercise is a key part of the recovery process. It can take up to 24 hours to fully replenish reserves with the correct intake of nutrients.

The hormone insulin may be necessary for muscles to absorb glucose to produce glycogen.

A number of studies show that insufficient sleep reduces the effectiveness of insulin.

This can affect the body’s ability to replenish glycogen stores. One study revealed reduced muscle glycogen stores after a night of sleep deprivation.

Decreased glycogen stores can impair subsequent exercise performance in the short and long term, so it is important to ensure that glycogen stores are replenished after exercise.

HOW TO SLEEP WELL

Sleep is clearly important to your fitness, so here are some ways to make sure you get a good night’s sleep:

• Develop a consistent bedtime routine: do things before bed that help you relax and wind down — like reading a book or listening to relaxing music. Taking a warm bath before bed can also be beneficial, as the subsequent drop in body temperature can help you fall asleep faster.
• Create a good sleeping environment: Exposure to light during the night can reduce the quality of sleep, so try to block out as much light as possible. Try to keep the room ventilated, but not too cold. A very hot or very cold environment can interfere with the quality of sleep.
• Be physically active during the day: Research shows that physical activity is beneficial for sleep quality, so try to include some exercise or physical activity in your day.
• Keep a consistent sleep schedule: This will help regulate your sleep-wake cycle, which has been linked to improved sleep quality.

If you’re trying to improve your fitness, make sure you’re getting enough, good quality sleep—aim for at least seven to nine hours of sleep each night.

* Emma Sweeney is Professor of Exercise, Nutrition and Health at Nottingham Trent University in the UK.

Ian Walshe is Professor of Health and Exercise Sciences at Northumbria University in Newcastle, UK.

This article originally appeared on The Conversation academic news site and is republished here under a Creative Commons license. Read the original version here (in English).