How Quality Sleep Makes You A Better (And Happier) Runner
Sleep is healing, repairing your muscles and rejuvenating your mind. To let you in on a secret, yes, sleep helps you run better and running helps you sleep better. Think of sleep as an essential tool in your recovery kit, with quality sleep being key.
A multitude of factors goes into keeping you feeling energised day-to-day – from your health to your hormones – and all of these are affected by your sleep. Sleep is more than just a state of unconsciousness - your eyes may be closed but your body and mind are working to recover and rejuvenate. Working to recover may sound like a paradox, but when it comes to sleep, they go hand in hand on a cellular level.
Sleep is complex. To make it simpler, we’ve broken it down into its main stages, non-REM sleep to support your body and REM sleep to support your mind. In Part 1 of our Sleep Series below, we’ll discuss the benefits of sleep on your running performance and everyday life – from your muscles to your mental health.
Non-REM Sleep: Restful, Repairing & Restorative
A sleep cycle consists of non-REM (non-rapid eye movement) and REM (rapid eye movement) sleep. Each sleep cycle lasts 90 - 120 minutes for adults, and usually you’ll experience 4 – 5 of these sleep cycles during your nightly shut-eye.
Non-REM sleep can be divided into multiple stages; when you first transition from wakefulness into sleep, fall into a light sleep and then into a deep sleep. It consists of about 75% - 80% of your total sleep time.
During non-REM sleep your muscles gradually become more relaxed and your lungs take deeper and slower breaths. Your heart rate, body temperature and blood pressure all decrease. This reduction in blood pressure during non-REM sleep may help reduce your risk of cardiovascular disease.
Throughout the deep sleep stage of non-REM sleep, your body goes into ‘recovery mode’. This phase is also called ‘slow wave sleep’ as your brain activity is at its slowest, essentially being at rest. Therefore, it's also the most jarring to be woken up from. If you’ve woken up suddenly during deep sleep, you would have experienced sleep inertia – a sensation of grogginess and disorientation.
During the deep sleep or the restorative phase, your oxygen and nutrient-rich blood is redistributed in part from the brain to your muscles to promote muscle repair and tissue regeneration. Non-REM sleep also plays a major role in supporting the building of bone, your immune system health and metabolism.
Gaining quality, uninterrupted shut-eye throughout the deep sleep stage is primarily responsible for feeling fresh and full of energy upon waking. Although there's still a lot we don't know about the science of sleep, studies suggest that during non-REM sleep your body experiences a surge in the energy-carrying molecule ATP (Adenosine triphosphate). ATP is essential to fuel cellular activity - including supporting healthy brain function.
REM Sleep: Improves Cognitive Function & Emotional Wellbeing
During REM (rapid eye movement) sleep or the ‘dreaming’ stage, your brain activity increases. Your body is temporarily paralysed (atonia), with the exception of the muscles responsible for breathing and your eyes which dart around beneath closed eyelids.
This ‘active’ sleep phase typically occurs at least 90 minutes into falling asleep, and takes up about 20% - 25% of the total sleep time of adults.
About 50% of a baby’s total sleep time is REM sleep, or more for premature babies. As REM sleep is largely responsible for supporting learning, it makes sense that newborns – experiencing the world for the first time - would spend more of their total time within this stage.
As the night goes on, the duration of the REM sleep phase of your sleep cycle becomes longer. Your brain activity, blood pressure and heart rate increase. Not all dreams occur during REM sleep, but it is the stage where your dreams are the most vivid. Alongside learning, REM sleep is responsible for other cognitive functions including the consolidation of memory, increasing your creativity and regulating your mood.
Now for the fun part - we’ll discuss the benefits of gaining regular, quality sleep and how these can be applied into your running.
The Benefits Of Sleep On Your Running Performance
Supports Muscle Growth & Repair
Muscle breakdown and repair is a natural part of your training. ‘Breakdown’ may sound like a negative - don’t worry though! It’s all part of the process to build your muscles back stronger.
This muscle breakdown occurs through physical movement like running resulting in tiny tears to your muscle fibres. When you experience muscle pain, tenderness or fatigue in the 12 – 24 hours following a workout, most likely you’re experiencing DOMS (delayed-onset muscle soreness) as a result of these tears and your body’s inflammatory response.
DOMS occurs particularly when you’ve increased your training load (speed/intensity or distance/duration) or are using your body in new ways. This exercise-induced muscle pain can be reduced though – you guessed it – quality sleep.
During non-REM sleep, Human Growth Hormone (HGH) is released from your pituitary gland at the base of your brain. Human Growth Hormone has a key role in triggering the growth and repair of your muscles and tissues – a metabolic process called muscle protein synthesis.
Inadequate, interrupted or poor quality sleep on the other hand, can result in deficiency of this hormone, slowing recovery time and potentially resulting in muscle degradation.
Prioritising quality sleep allows your body to build strong, lean muscle mass and adapt to an increased training load while reducing your risk of injury. It’s true – your body is literally building muscle in your sleep.
Strengthens Your Immune Function
Your motivation to run drops when you’re feeling under the weather, throwing you off track of your fitness routine. Quality sleep helps ward off illness through the production of cytokines – immunity-boosting proteins that help regulate your body’s inflammatory response and the growth of immune system cells.
Cytokines are responsible for the communication between white blood cells to stimulate an immune response – including sending messages that trigger the death of abnormal, potentially cancerous cells, and that support the increased lifespan of healthy cells. Alternatively, sleep deprivation can weaken your immune system and put you at greater risk of infection and susceptibility to certain cancers.
When your body is invaded by a pathogen (e.g., bacteria, viruses), experiencing inflammation or is under excess stress, its demand for protective cytokines increases. A quality night’s sleep will boost your cytokine levels, speed up and support your recovery from the inside out.
Sleep also increases the production of white blood cells including infection-fighting T-cells that support immune system function by attacking foreign substances such as infectious disease (e.g., common cold, COVID-19). This is a reason why you feel more fatigued when you’re sick – a cue from your body that you should sleep. You may also feel more tired than usual as your body is allocating more of your energy towards combating the illness.
Alongside sleep, running itself also has immune system boosting benefits. Running increases the circulation of white blood cells that are responsible for creating disease-fighting antibodies, and increases your respiration rate to expel pathogens from your lungs before an infection takes hold.
Running also naturally increases your temperature through muscle movement – doubling up as a mechanism to impede bacterial growth and reduce infection, similarly to a fever. Fevers themselves are a symptom, not an illness and function as part of your body’s immune system response.
Rather than being put on the sidelines of your training, sleep well to allow yourself to run consistently and regularly without interruptions from illness. When marathon day rolls in, you’ll feel primed to perform knowing you’ve put the training in.
Improves Mental Health & Regulates Your Emotions
It’s no secret that anxiety and depression can spark havoc on your motivation to exercise. When sleep deprived, your productivity on and off the road can decrease and emotionally you’ll feel more prone to stress and irritability. The little day-to-day pressures in life that you usually brush off may trigger a more dramatic emotional response.
If we take a look into the science of sleep and put your amygdala under the spotlight, you can gain a better understanding of the connection between your sleep and your emotions. Located in the temporal lobe, your amygdala is the ‘emotional control centre’ of your brain. It’s responsible for stabilising your emotional response to stress.
During REM sleep, the amygdala transmits information to the hippocampus (a brain structure that’s critical to learning and memory) – essentially training your brain on how to manage emotional stimuli. When sleep deprived, you may struggle to process emotion and may be more prone to anxiety – with the amygdala unable to adapt to a stressful situation in a healthier, more positive way.
Inadequate sleep can also cause your body to react with a stress response, resulting in the release of cortisol, the stress hormone. With sleep deprivation inhibiting your body’s ability to regulate hormones, you may suffer from cortisol in excess, resulting in an increased heart rate as part of your ‘fight or flight’ response.
What was historically a natural survival mechanism when facing a threat (e.g., outrunning a predator… or in today’s world, preparing for a job interview) can turn not only counter-productive when in overdrive, but be damaging to your overall health. Chronic stress increases your risk of cardiovascular disease by overworking the heart and can put you at risk of high blood pressure.
Inadequate sleep also increases your perception of effort, meaning when you’re sleep deprived and fatigued, everything feels harder - whether you’re running or washing the dishes. You may suffer from ‘brain fog’ when you haven’t gained quality shut-eye – with your decision-making skills inhibited and a higher level of focus out of reach.
By prioritising quality sleep, you can restore your body’s hormone levels to a healthy balance, enjoy the positive benefits of running on your mental health and put your daily stresses more easily to rest. With an uplifted mood that makes you feel radiant and ready to run, motivation will come easier to lace up and hit the pavement.
Consolidates Your ‘Muscle Memory’
Quality sleep supports the consolidation of memories, meaning new skills you’ve learned are more likely to stick and stabilise, and superfluous memories can be discarded. During sleep, your mind makes connections between memories – aiding in problem-solving, decision-making and giving real-world value to the phrase ‘sleep on it’.
Quality sleep helps support the development of your motor skills, strengthening neural pathways between brain and muscles to reinforce procedural memory, more commonly referred to as ‘muscle memory’.
‘Muscle memory’ – your ability to perform a physical task as second nature – is attributed to myelin. Myelin is the fatty substance that forms an insulating, protective layer around nerve fibres (a myelin sheath), including those of the brain and spinal cord. It ensures that electrical impulses or nerve signals can be ‘fired’ and transmitted swiftly between brain and body.
Whether running, catching a netball, playing the piano or doing complex plyometric (fast and explosive) exercises, healthy myelin allows you to run on ‘autopilot’ when performing repetitive motor skills that you’ve trained for over time. Sleep activates genes responsible for the production, repair and maintenance of myelin, allowing it to become thicker to improve nerve conduction and therefore, improve your muscle memory to make the most out of your training.
For runners, quality sleep not only helps with the voluntary muscle movement of churning one leg in front of the other. It also aids in involuntary muscle movement like your heart beating - supporting your heart’s ability to adapt to an increased training load. This means that alongside regular training, quality sleep can help you to run at a higher intensity, under less stress or less effort, and at a lower heart rate.
Even after a running hiatus, when you’re training has ceased or slowed down for weeks or months due to travel, pregnancy, or other commitments – this ability of sleep to support the storage of memory allows you to more smoothly transition back into running. Of course, the more you get into a habit of running consistently, the stronger your ‘muscle memory’ will be.
Sleep well and happy running!