The Importance of Sleep for Exercise & Recovery

We all know how much better we feel after a good night’s sleep. Sleep is incredibly important for our health. In fact, it’s just as important as eating a balanced, nutritious diet and exercising. The quantity and quality of sleep we get each night affects both our physical and mental performance the following day. Neuroscientist Dr Walker believes “sleep is probably the greatest legal performance enhancing drug that few are abusing enough”. 

Sleeping for 7-9 hours per night is essential when exercising regularly towards a fitness goal. Especially if you want to change your body composition, increase muscle mass and/or be recovered and ready for a workout the following day.

Sleep is the most potent recovery tool known to science, nothing else compares.  ‘Often when we hear the word recovery, we think of post-workout meals, adequate protein, rest days and myofascial release. Whilst all of these have a place in muscle recovery post-exercise, they will never be able to achieve the same recovery results as one activity that we all perform daily, yet often neglect: sleep,’ Nathalie Lennon, Polar ambassador, personal trainer and nutritionist. 

Sleep allows the heart to rest while also allowing cells and tissues to repair. Sleep replenishes your energy stores and recharges your central nervous system (CNS). If you do not allow your CNS to recover, your fitness will suffer because the CNS is in charge of triggering muscle contractions, reaction time, and pain response. During exercise, you will become slower, weaker, and possibly less coordinated. A 2019 study published in the Orthopaedic Journal of Sport showed that athletes who slept eight hours a night lowered their risk of injury by a massive 61 %.

When asleep the body repairs any damage done during the day. There are 3 stages of sleep; light sleep, deep sleep and REM (rapid eye movement). In deep sleep the body releases hormones which it then uses to recover. Hormones involved in tissue repair, like testosterone, cortisol and human growth hormone (HGH) spike in the deep sleep phase. These hormones break down and rebuild damaged muscle cells, helping them heal and repair. 

This repair leads to muscle growth and physical fitness improvements over time. In deep sleep the brain is resting so the blood supply available to muscles increases, delivering extra oxygen and nutrients to facilitate healing and growth. The muscles and tissue are rejuvenated in deep sleep.

A sufficient amount and quality of sleep is not only beneficial to exercise and recovery, but it is also necessary for our overall health and well-being. Getting enough sleep is linked to better overall mood, less irritability, and a lower risk of developing depression and anxiety. Sleep also helps to keep you healthy by producing cytokines, hormones that help your immune system fight infections.

Despite knowing how important sleep is and how much better we feel, perform and recover when we get a good night’s sleep, we still fail to get enough. Sleep loss is on the rise with 1 in 4 of us having sleep problems. Technology, diet, unprecedented stress levels, social drug use and our changing, complex world all play their part in disrupting our sleep.

Sleep deprivation reduces athletic performance by causing fatigue and inhibited ability, which can halt fitness gains. Sleep deprivation can also have a negative impact on cardiorespiratory endurance, hand-eye coordination, reaction time, mood, and the immune and endocrine systems. Sleep deprivation increases the risk of injury as well as the development of many medical conditions such as type 2 diabetes, high blood pressure, kidney disease, and stroke.

It is so important to pay attention to your body. Do you feel weak, unmotivated or unbalanced? You could be overtired. Stop exercising before you injure yourself.  If you have problems sleeping, are overtired and struggling to function then you should contact your GP to discuss this with them.  If you are simply not getting enough sleep or your quality of sleep is poor there are a few things you can try:


Tips to help improve sleep:

  • Create a calm and relaxing sleep environment.
  • Have blackout curtains in the bedroom window.
  • Keep your bedroom cool, a temperature of 68-72°F / 20-22°C is recommended.
  • Avoid alcohol and caffeine before bed.
  • Don’t use electronics before bed. The blue light emitted form laptops and phones trick your brain into thinking its daytime. 
  • Have a wind down routine every night.
  • Eat a healthy diet, avoiding excess salt, sugar and processed foods.
  • Deep breathing exercises help you settle into a relaxed state.
  • Shower before bed, the temperature change triggers the body into pre sleep state.
  • Go to sleep and wake up at the same time every day to get yourself and your body into a routine. The circadian rhythm (body’s internal clock) needs consistency.
  • Eat 1-2 hours before bed. 
  • Manage your worries. Write a list if your mind is whirling with things to do and remember.
  • Aromatherapy.
  • Listen to music to create a calming, relaxing feel.
  • Read a book.
  • Fresh sheets create a sense of comfort.
  • Limit daytime naps as these can interfere with nighttime sleep.
  • Drink herbal tea such as chamomile, lavender and valerian root are known relaxants.
  • Drink plenty of water.
  • Regular exercise helps you to fall asleep quicker.


Our attitude to sleep needs to change. Sleep is an essential function and should be made a priority in our busy schedules.  The good news is this is something you can change today. Go to bed earlier-start tonight!