What is the connection between fitness and sleep?

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It may seem very simple to sacrifice a few hours sleep so you could squeeze in some exercise. In that case, you are one of the UK's 37% who report getting less than adequate sleep at night. 

However, not catching those forty winks may do more harm than good, especially if you are training hard. See further analysis infographic on this link

Sleep and fitness are closely linked. Sleep deprivation prevents you from reaping the benefits of physical activities, whereas working out is pointless unless you get a good night’s sleep.

How do quality and quantity of sleep affect your running performance?

While a person sleeps, the body recovers, and at the same time, it repairs and builds muscles that have been worked during the day.

Usually, when performing vigorous exercises such as running, muscles develop microscopic tears, and sleeping well helps heal them. This usually happens in stage three of sleep, known as the most restorative sleep stage.

When you are in a deep sleep, blood that is not used by your resting brain is sent to your muscles. They receive the extra oxygen and nutrients, and muscle tissue is replenished and regenerated.

Another factor that aids muscle repair is HGH (Human Growth Hormone). This hormone is released during deep sleep and helps muscle recovery, strengthens bones, and even turns fat into fuel. On the other hand, lack of sleep reduces HGH secretion, thus lowering recuperation time from workouts and injuries.

So better sleep equals stronger muscles. But how else can sleep help you run better?

study published in the European Journal of Applied Physiology shows that athletes who ran after not sleeping for almost 30 hours reported feeling less endurance. In addition, they claimed that sleep deprivation also affected their pace, breathing, heart rate, and body temperature. In other words, they became tired faster.

Sleeping soundly has an effect on your state of mind, too. Research shows that runners who missed sleep even on one night had a higher perception of effort for a given level of exercise.

Furthermore, quality sleep is proven to give people the will, concentration, and stamina to complete a race or an exercise regime. Sleeping well means faster reaction time, more rest, and less fatigue. From this perspective, pressing the snooze button on your alarm does not seem like a bad idea.

How does exercise help you sleep?

Simply put, the more active you are, the more rest you need. Anyone who has run a marathon or gone hiking can testify that they slept like a baby afterward.

Exercising regularly also adjusts your circadian rhythm, i.e., the body’s internal clock, by providing it with a healthy daily routine. That way, your body and brain know when it is time to sleep and when it’s time to get up and get going.

Finally, moderate exercise before bed is shown to relax your mind and body, allowing for a more restful and deeper sleep. People who do yoga or light fitness prior to bedtime say they slept better and woke up less during the night. 

In conclusion


There is a close relationship between keeping fit and sleeping well. When you are physically active, your body craves rest. Additionally, having a regular sleep schedule improves your well-being and health, making it less likely to suffer from an injury or tiredness.

Hence, getting some shut-eye is one of the most crucial factors in reaching peak athletic performance.