We all know that getting a good night’s rest is important. From cognitive performance and memory consolidation to hormone production, a functioning immune system and emotional regulation, sleep plays a vital role in just about every aspect of the body.

“During sleep, every part of our body rests, restores and renews itself. Injuries repair, hormones are released and the brain sorts through and processes the thousands of pieces of information from the day,” explains Max Kirsten, certified sleep coach and resident sleep expert at Innermost.  

Sleep is also a critical component of exercise recovery. In fact, Dr Justine Ward, co-founder of Thirdzy, argues it’s the most effective recovery tool there is: “All of the results of working out – muscle building, bone strengthening, skill acquisition and endurance improvements – happen after you exercise and are a product of your body recovering from training.”

Author of The Science Of Sleep Heather Darwall-Smith agrees, explaining that our bodies create new proteins to rebuild and strengthen the muscles when we sleep. Deep sleep, known as delta or slow-wave sleep, is crucial in facilitating this repair, she tells Stylist. “During this time, the body releases growth hormones which are essential for muscle growth and repairing tissue damage.”

Loss of sleep can have a huge impact on both our recovery and performance. “Sleep deprivation causes a drop in growth hormone production resulting in a loss of muscle mass and reduced exercise capacity,” says Darwall-Smith.  

“Without an adequate amount of quality sleep, it will take you longer to recover between workouts and you’re more likely to experience exhaustion when exercising,” adds Ryan Thaker, sleep expert at MattressNextDay. “This, in turn, means you’re more prone to injury and less likely to perform optimally.” 

So, given that sleep is such a powerful tool for exercise recovery, does that mean people who are physically active need more shut-eye than those who lead a sedentary lifestyle?

According to Dr Verena Senn, sleep expert at Emma Sleep, the short answer is ‘yes’. “Increased levels of exercise will often require greater amounts of sleep as your body needs more time to rest and recover from the additional strain you’re putting it under,” she says. She points to professional athletes, many of whom get at least 10 hours of sleep each night as a key part of their training programme.

Evidence backs this up. A 2020 study published in the Journal Of Science And Medicine In Sport revealed that endurance athletes who slept for less than seven hours a night were 50% more likely to suffer an injury over a two-week period, while another study found that athletes who slept for at least eight hours decreased their risk of injury by up to 60%.   

Even if you’re not training to the same level as an elite athlete, says Dr Senn, if you’re someone who is very physically active, getting enough sleep is vital to facilitate your training and help you reach your fitness goals.

Do the type of workouts we do have an impact on how much kip we need? Darwall-Smith says it’s down to the intensity of the exercise. “High-intensity exercise means more muscle damage so your body needs additional time to repair.”

“The elevated heart rate activates the sympathetic nervous system and increases stress,” she explains. “Without allowing enough time to sleep, the physiological opportunity to recover might be compromised.”

So, activities like HIIT, running, weight training and team sports may require additional sleep while more gentle forms of movement like yoga and pilates won’t need as much recovery time.

Fitness expert and WithU Training ambassador Rory Knight feels it’s important to point out that regardless of the type of exercise you do, getting sufficient rest should be a priority. “While all exercise is not equal in terms of the required sleep needed to perform optimally,” he says, “there are factors of every sport that require sleep as a means of allowing muscle, mental and general health recovery.”  

The Sleep Foundation recommends the average adult gets between seven and nine hours of sleep a night. “If you’re focusing on hitting fitness goals whether that’s gaining muscle mass or improving your running pace, getting at least seven hours of sleep is pivotal,” says Knight. “If you’re sleeping for just four or five hours, you won’t get enough REM sleep, which is completely necessary for recovery.”

Dr Kat Lederle, head of sleep at Somnia offers an important reminder that while seven to nine hours is the general recommendation, our sleep needs are highly individual. “More intense exercise will use more energy but this doesn’t necessarily mean you will need more sleep than someone who sits at a desk all day,” she says. “It depends on the person and various factors like age, sex, genetics and fitness level.”

Dr Lederle believes focusing on quality over quantity might be more useful when it comes to sleep. If you sleep for eight hours but that sleep is fragmented and of poor quality, you won’t recover as well as if you had six hours of good quality, restorative sleep. 

“Don’t obsess over the exact amount of hours in bed you should get,” she advises. “Instead, focus on creating a sleep-friendly environment and giving your body the time it needs to rest and recover after working out.”

If you’ve had a particularly active day, says Dr Lederle, it’s probably worth getting into bed a bit earlier and seeing if your body takes the extra rest. “It’s like with food – on some days you’ll need more and some you’ll need less,” she explains.  

For Darwall-Smith, it’s important to understand the bidirectional relationship between exercise and sleep. Our sleep habits affect our exercise performance, and conversely, our fitness routine impacts how well we sleep.

“While it is generally understood that sleep and movement are good friends, too much exercise can negatively impact sleep,” she explains. “Ultimately, it’s about finding the right balance between intensity and endurance and rest and recovery so your body can thrive.”

The bottom line? Sleep should be a non-negotiable part of your fitness routine, regardless of how you choose to move your body and how active you are. Aim to get between seven and nine hours in bed each night but remember, sleep needs vary from person to person. Focus on doing what you can to get good quality sleep, and on days you go extra hard, allow your body additional time to rest and recover.  

If you’re looking to improve your sleep quality and optimise recovery so you can keep smashing your workouts, these varied tips from the experts should help.

Keep a sleep diary

If you’re struggling to sleep and it’s having a knock-on effect on your fitness, Dr Senn recommends keeping a sleep diary and making a note of how your exercise habits impact your sleep. “You can then work out the best way to approach your routine so you find the right balance between exercise and rest to maintain a healthy lifestyle.”

Don’t overdo it

Too much high-intensity exercise can lead to hyperarousal, which is a key element of insomnia,” explains Darwall-Smith. “Excessive HIIT is a stress on the body and can disrupt sleep. It should be limited to two or three times a week to allow for enough recovery time.”

Avoid high-intensity exercise before bed

In the same vein, evening HIIT workouts are probably best avoided. According to Dr Lederle, an intense workout at night can make it harder to fall asleep as it elevates our body temperature and floods the body with adrenaline and cortisol.

Try bedtime yoga

Yoga, on the other hand, can help promote sleep. “Studies show that mindful forms of movement like yoga can induce a 27% increase in the release of GABA (gamma-aminobutyric acid), a brain chemical that lifts the mood and calms the soul,” says psychologist and sleep expert Hope Bastine. “The calming effect facilitates both sleep ability and sleep quality.”

Manage your stress levels

Darwall-Smith recommends paying attention to your stress levels. “I often see people for sleep issues, but when we dig deeper and examine their lifestyle, the realisation that a heavy training schedule alongside a stressful job could be the primary problem.”

“It’s so important to make space in your schedule to wind down, relax and sleep,” she continues. “Active relaxation like stretching, gentle yoga and breathwork can be incredibly helpful.”  

Find a sleep schedule

Waking up and going to bed at the same time every day will help with sleep quality. “Like most things to do with sleep, consistency is key,” says Dr Senn. “Following a regular sleep pattern enables your body to ‘learn’ when sleep is due and when to produce the right hormones accordingly.”

Think about your sleep hygiene

Sleep hygiene refers to a set of behavioural and environmental recommendations used to promote sleep, explains Dr Senn. “It can be simple things like reading a book, having a bath before bed or making sure your bedroom is cool, quiet and dark but they can have a major impact on your sleep duration and quality.”

Fuel your body

Evidence shows our eating habits can have a significant impact on our sleep quality. Darwall-Smith says ensuring you’re getting enough protein throughout the day will keep your blood sugar levels from spiking and reduce cortisol levels.

Consuming a sufficient amount of carbohydrates is also key. “Carbohydrates increase levels of the essential amino acid tryptophan in the brain,” she explains. “Tryptophan converts to serotonin which supports the production of the sleep hormone melatonin.” 

Images: Getty