The Impact of sleep on your health and fitness

The Impact of sleep on your health and fitness

Top athletes and sports teams know how important a good night’s sleep is to being able to perform at your very best. Cycling’s Team Sky go to extraordinary lengths taking their own mattress with them from hotel to hotel, plus a washing machine to ensure that their riders have freshly laundered sheets every night. But how much do we know about the impact getting too little sleep has on our health and fitness?

Neuroscientist and Sleep Researcher Matthew Walker in his book ‘Why We Sleep’ clearly sets out the importance for adults of getting 7-8 hours of sleep every night. More importantly he highlights the significant impact not getting enough sleep can have on bodies and brains. Yet many of us regularly fail to achieve recommended number of hours sleeps per night. Worse still routinely getting less than 6-7 hours sleep can have a dramatic impact of various aspects of your health, and according to Walker can shorten your life.

However scientists are now developing a much better understanding of sleep. They are beginning to understand its amazing ability to enable the body and brain reset and recover for the next day. They are also revealing the impact of not getting sufficient sleep on our health and other aspects of our lives.

How does a lack of sleep impact on our health and fitness?

Do you find that you reach for less healthy foods when you are tired?  Well when you haven’t had enough sleep there is an upsurge in the hormone that makes you feel hungry (Ghrelin). At the the same time the hormone that tells you that you are full (Leptin) is suppressed.  So not only are you more likely to eat more when sleep deprived, but you have reduced impulse control and are therefore more likely to reach for unhealthy snacks. Therefore a lack of sleep sets you up to want to eat more and potential weight gain.

Worse still the less you sleep, the less energy you feel you have. As a consequence you are less likely to be active during the day.  And as a final blow, if you do diet while sleep deprived weight loss is more likely to come from reduced muscle mass rather than excess fat.  Scientists have also shown that even moderate disruptions to your sleep over the course of a week can greatly disrupt a healthy person’s blood sugar levels.  The good news here is that getting enough sleep will restore the balance of chemicals in your brain helping you to better control body weight.

The impact of Sleep on physical activity

It probably isn’t too much of a surprise that getting a solid night’s also improves your athletic performance. Having less than 8 hours sleep will mean you become physically exhausted much quicker. Your ability to produce energy aerobically when exercising at lower intensities is less effective, muscle strength and power is reduced, and your cardiovascular and respiratory systems are impaired resulting in lower blood oxygen saturation. It even impacts on your ability to keep cool through sweating.  Also a chronic lack of sleep over a longer period dramatically increases your chances of picking up an injury.

Sleep is equally important the night after activity, ensuring that the body’s recovery is maximised overnight.  It improves motor skills memory so you are better able to produce a skillful performance. Sleep reduces muscle fatigue and increases your perceived levels of energy too. Even a short daytime nap can improve your athletic performance.

Researchers have also found that regularly not getting enough sleep can have serious implication for your long term health.  Routinely sleep less than 6 or 7 hours per night greatly increases your risk of developing cancer and increases the likelihood of coronary arteries becoming blocked leading to a higher risk of cardiovascular disease. It also greatly reduces the effectiveness of your immune system in fighting off illness. (To the extent that a poor night’s sleep can impact on how effective your flu jab will be!) Additionally, not getting enough sleep has been identified as a lifestyle factor influencing whether you might develop Alzheimer’s disease.

Can I catch up on Sleep?

No, research shows that if you are deprived of sleep on one night, you can never fully catch it back up.  Given the opportunity, you will sleep for longer on subsequent nights. Your brain will do it’s best to catch up on the important functions missed on the night you slept fewer hours. But studies show your brain never fully catches back up.  So if you sleep longer at the weekend to make up for early starts and late evenings during the week, it will make you feel better but you won’t fully make up for the sleep lost in the first place. Much better is consistently getting a full night’s sleep every night.

How else does too little sleep effect you?

Getting a good night’s sleep has been show to boost learning. This is because the brain transfers information from short to long term memory during sleep.  Similarly a lack of sleep affects your memory and recall of information.

Scientists have also shown that getting adequate sleep can increase your creativity, and make you more productive throughout the day. This suggests that reducing the amount of sleep you get to work longer hours and get more done may actually be having the opposite effect! Getting more sleep could enable you to get more done in less time at work.

Additionally driving while sleep deprived greatly increases the likelihood that you will be involved in a road traffic accident. It can be a greater impairment than being under the influence of alcohol or drugs!

Tips for sleeping better

Consistency:  Try go to bed and wake up at the same time everyday. Give yourself the opportunity for a full 7-8 hours sleep a night. That could mean giving yourself up to 9 hours in bed to achieve this.

Regular exercise: Aiming to get 30 minutes of activity on most days will help. However try to do this 2-3 hours before bedtime otherwise the rise in body temperature after exercise can prevent you sleeping.

Avoid Caffeine, Nicotine and Alcohol:  Caffeine is a well know stimulant that can take up to 8 hours to clear your system. A caffeine hit to keep you going when you are tired will also stop you dropping off at night. A vicious cycle if you then reach for more coffee the next day due to a poor night’s sleep. Nicotine is another stimulant that causes very light sleep as well as waking you early due to nicotine withdrawal.  Alcohol is also a stimulant that can impair deep sleep and cause you to wake during the night.

Napping:  A nap during the day can be beneficial. However, napping after 3pm can make it a hard to sleep when you do go to bed.

Make your bedroom sleep friendly:  This may sound obvious, but it should be dark, cool and distraction free.  Blackout blinds will block out light that deters the onset of sleep. A slightly lower temperature helps trigger sleep.  Try to remove other distractions such as gadgets and noise. Tablets, mobile phones and other devices have LED screens that emit ‘blue’ light. This suppresses the release of Melatonin, the hormone that triggers sleep.

Make time to relax before bedtime:  In our busy lives we often struggle to make time to wind down before going to bed. This mean we head off to bed with our brain still working away.  Read a book, listen to music, have a bath –whatever works for you. (Although remember avoid staring at an LED screen).

For more tips and information on sleep issues visit

For a much more in-depth look at the importance and purpose of sleep and the impact that sleep can have on your health pick up a copy of ‘Why We Sleep’ by Matthew Walker (Penguin Books, 2018).