Importance of Sleep for Health and Performance

To meet your fitness and lifestyle goals, your focus shouldn’t just be about optimizing your activities during the waking hours, like physical activity and diet — it should also be on focusing on and prioritizing sleep. 

When you are dealing with a busy schedule packed with work, family, and training obligations, it’s easy to sacrifice a few hours of sleep here and there. Those hours add up, and the sleep debt you accumulate can diminish your performance in all aspects of your life. 

A less than ideal sleep schedule is a common problem for American adults. In fact, the National Sleep Foundation reports that around 40 million U.S. adults are afflicted by a sleep disorder, while 60% deal with sleep problems at least a few nights each week. Sleep disorders and sleep deficiencies are often brushed aside, but it’s important not to ignore these issues.  

It’s essential to understand the extensive role sleep plays in daily functioning and overall wellness, and to take action to make sure your sleep habits aren’t holding you back. Things as simple as a regular, effective sleep schedule, and setting up your space and body for optimal rest and efficient sleep can lead to enormous health gains.

Why Sleep is Important: Digging Into the Science

In recent years, there has been a large focus on the importance of sleep in scientific research. Studies have found that getting enough sleep is hugely beneficial for both the mind and body. Benefits include:

Improved Recovery and Performance

Whether you are focusing on recovery after a grueling high-intensity workout or gearing up to perform in an upcoming marathon, getting enough sleep gives you the best chance possible at meeting your exercise objectives.

Sleep, particularly the deep sleep stages that support restorative sleep, plays a major role in the body’s repair and healing processes. The blood vessels, bones, muscles, immune system, and other cells and tissues all rely on sleep for necessary repair to continue functioning properly. After physical exertion, getting enough quality sleep is necessary to support recovery. 

Sleep can also give performance a boost. By supporting physiological recovery, sleep helps you see physical gains from exercise — such as improvements in muscle mass or strength.

Additionally, sleep supports immune and cardiovascular health, ensuring that you are in great shape to perform at your best. In one study, researchers found that getting extra sleep improved the athletic performance of college basketball players - suggesting that increasing nightly sleep can directly benefit physical performance.

Improved Memory and Cognition 

Focusing on improving your sleep is also beneficial for your mental performance. Sleep plays a key role in several cognitive processes, including memory, learning, decision-making, and problem-solving — all of which are important for excelling in day-to-day activities. Research has found that sleep supports several different aspects of memory, including long-term memory, memory consolidation and recall.

Research has also explored the impact of sleep on other cognitive functions. For example, in one study, researchers either woke up participants during REM sleep (the deep stage of sleep linked to abstract reasoning and creative thinking) or non-REM sleep and asked them to solve anagram puzzles.

When woken during REM, participants exhibited a 32% boost in performance, indicating that this stage of sleep can boost reasoning and problem-solving abilities. Another study found that more optimal sleep habits, including getting more sleep, sleep consistency over several days, and sleep schedule, were associated with increased performance in college coursework. Students who got more sleep and went to bed earlier on average got better grades. These findings indicate that sleep can boost focus and overall cognition.

Improves Mood and Happiness

A consistent sleep schedule can also support improvements in mood and happiness. When you get enough sleep, you will feel less tired during the day and experience increased energy levels. In addition, sleep is essential for emotional processing, and individuals who get enough sleep are more likely to be able to deal with emotions and everyday stress well and have a positive overall mood.

Research has found that individuals who get less than 6 hours of sleep per night are more likely to report symptoms of depression, while individuals who get more than 7 hours report less depression symptoms and greater happiness.

Sleep consistency, meaning going to bed and waking up at roughly the same time daily, is also essential in informing sleep quality and mental health. Extensive research indicates that sleep duration is important, but the current findings highlight the fact that the general recommendation to increase time in bed might be incomplete advice on its own.

Instead, a focus on sleep consistency, in addition to sleep duration, might yield more benefits. The positive correlation between sleep consistency and psychological well-being means the more consistent your sleep and wake times are, the better your mental health is. 

During restorative sleep, or the deepest phases of sleep, the body also repairs and heals cells for optimal function, experiencing growth hormone release, tissue growth, protein production, and muscle repair, among other benefits. And as physical wellness can also play an important role in improving mood and overall lifestyle and daily function, clocking enough restorative sleep may also correlate to increased happiness.

What Happens When We Don’t Get Enough Sleep, Or Good Sleep

There are serious drawbacks to not getting enough sleep, inconsistent sleep, or poor quality sleep, in just about every area of daily life. When you regularly get less than the recommended 7-9 hours of sleep each night, you are likely to see a negative impact on your physical, social, and emotional health, including:

Reduced Performance In Daily Activities and Exercise 

Sleep deprivation decreases athletic performance and minimizes the gains that can be expected from exercise. Not getting enough sleep doesn’t just make it more difficult to perform in the gym — it also makes completing daily activities more challenging. 

Fatigue reduces energy levels, contributes to the slow down of cognitive processing, and decreases reaction time. Everyday activities like thinking, focusing on a task, and dealing with stressors become taxing — affecting performance at home or in the office.

One study found that participants who reported higher scores of sleep difficulties had worse work performance ratings, more days absent from work, and greater healthcare costs throughout the two year study period.

Unhealthy Eating Habits

Sleep deprivation and unhealthy sleep habits can contribute to the development of other unhealthy habits.

Research has found that getting less than the recommended amount of sleep and having poor quality sleep is linked to eating more, snacking more often, and consuming more foods containing high in fat and carbohydrates. Results showed that sleep–wake cycles are strictly controlled by circadian rhythm, and exert a strong effect on the circulating levels of ghrelin and leptin, which are hormones that regulate appetite and caloric intake.

Additionally, the data suggested that “short sleep duration may be associated with an increase in the hormone ghrelin, which stimulates hunger, and a decrease in the saturating hormone leptin, leading to increased food intake to combat fatigue or stress, among other possible mechanisms.”

In another study, participants who increased their sleep by 1 hour each night were found to eat less on average than they had before improving their sleep habits. 

Difficulty Engaging in Social Activities and Conversations

When you don’t sleep enough, your social life can also be negatively affected. Cognitive impairments related to a lack of sleep can lead to issues with holding a conversation and communicating with others.

Researchers studied the brains of individuals dealing with sleep deprivation and found that there was reduced activity in brain regions associated with social engagement, and increased activation of neural networks correlated with social repulsion. The researchers concluded that sleep deprived individuals are more likely to experience social withdrawal and loneliness.

How to Prioritize Sleep

While sleep deprivation and sleep disturbances can have extensive negative effects on daily life and performance, there are plenty of steps you can take to improve sleep and lessen many of these effects, without necessarily even getting more time in bed. Taking control of your sleep habits can lead to many improvements in your day-to-day experiences. Here are a few tips to get better sleep:

Aim for Sleep Consistency

Sleep consistency refers to following a regular sleep schedule where you go to bed and wake up at the same times each day – both on weekdays and the weekend. Research indicates that a commitment to sleep consistency is linked to more positive health and improved performance. WHOOP research has also found that improved sleep consistency was linked to more time spent in deep, restorative REM sleep. So if you can't get more time in bed, being as consistent as possible can provide significant benefits.

Track Your Sleep

Tracking your sleep can be a useful strategy to get insight into the quality of your sleep. For example, if you’re getting 8 hours of sleep a night but still waking up feeling unrefreshed and tired, understanding exactly what’s happening while you sleep can be beneficial.

WHOOP both collects data on your sleep, providing breakdowns of everything from sleep efficiency, consistency, and staging, and offers personalized suggestions on how to improve sleep quality. Independent validation of the sleep tracking provided by WHOOP by the University of Arizona found that using WHOOP was associated with increases in sleep quality – and that WHOOP provides lab-grade accuracy when it comes to sleep staging. 

Maintain a Sleep Routine

Sleep hygiene is a term for all of the habits included in your nightly bedtime routine. A consistent and targeted sleep routine can make a big impact on sleep quality and the likelihood that you will experience all of the positive benefits of getting enough sleep. It’s important to find the bedtime habits that work best for you — there is no one sleep routine that will automatically get you the results you want out of your sleep.

General tips include sleeping in a dark, quiet, and cool space, cutting down on screen time before bed, and limiting food, alcohol, and caffeine intake in the hours before sleep. It can also help to incorporate relaxing activities into your routine, such as taking a bath, meditating, stretching, reading, or listening to music. You can also use the WHOOP Journal to track different sleep promoting behaviors to understand their impact on you.

Improve Sleep with WHOOP

WHOOP provides in-depth, accurate sleep tracking that you can use to prioritize your sleep. WHOOP records time spent asleep, time spent in bed, sleep need, sleep performance, wake events, sleep efficiency, sleep consistency, and time spent in each stage of sleep. Based on this data, WHOOP offers individualized recommendations for getting the most out of your sleep, such as how much sleep you should aim for and what the optimal bed and wake times are to maintain sleep consistency.

Track your sleep with WHOOP to unlock the power of sleep to improve your daily performance and overall health.