Wellbeing & Motivation > The Sleep & Exercise Relationship: ​How Important is it?

The Sleep & Exercise Relationship: ​How Important is it?

31st Jan 20

Sleep and Exercise… Exercise and sleep… the two just couldn’t be much further apart. When you think of one, chances are, the other is nowhere in sight. However, despite their different natures, they’re actually more dependent on each other than you might think.

Sleep and exercise are actually in quite a harmonious relationship. We’ve already looked at how exercise helps you sleep, but did you also know that sleeping helps you exercise and to get all of the benefits from it too?

If you’re lacking in sleep, a whole world of problems can happen. We’re here to fight for the cause and walk you through each and every one of them to help you come to your senses. Your progress depends on it, after all.

Want to move fast? Jump to the right section below.

The Physical Side

Woman flexing

Believe it or not, sleeping is when you actually see most of the progress your exercise gives. You can train as much as you like throughout the day, but you will very quickly see a decline in your progress if your sleeping pattern is all over the place or if you are not giving yourself enough time in your day to actually get a good night’s rest. But, of course, it’s not just because you’re tired when you exercise, either.

Muscle Repairs

Man sleeping with barbell

Let’s start with your muscles. How your muscles react after you have been training, even if you have had a rest day that day, is actually reliant on your sleep. Did you know that?

Your muscles need to function throughout the day to help with daily tasks moving around. since you need them still, they don’t really have time to repair or rebuild. Luckily, there’s a time in your day when you’re not doing much at all… you guessed it. Sleep.

Once you are asleep, things get a little different. Your body consumes fewer nutrients due to the lack of movement required, and this means that your muscles really have time to be helped naturally. The dead cells in your body are replaced with new cells, while damaged cells are repaired or duplicated, which is where muscle growth occurs.

If you aim to see any improvements in relation to your muscle size or performance, sleep is exactly the thing you need the most. Don’t forget that!

Injury Prevention

Hamstring injury

It’s not all about getting bigger or stronger muscles, either. You need to stop and think about your physical health here too. Another more detailed side to this that many of us may not have considered is how this affects the likelihood of us sustaining an injury throughout our daily lives, or even more so in training.

If your muscles are not in the ideal state they need to be in, they are far more likely to be damaged by something that is not as significant as it usually would be. It’s an accident waiting to happen. Your muscles aren’t repaired as they should be.

Not letting your muscles repair themselves just leads to them being damaged further. This is one of the easiest ways to allow your muscles to be torn from overtraining, even when just following your usual routine! It’s even one of the biggest symptoms of overtraining in the first place.

Minimal Consumption

Woman sleeping with eye mask on

When you sleep, many of your organs go into a kind of standby mode. As a result, your heart and breathing rates lower, and digestion slows down. As a result, you don’t need as much energy, so it’s only natural.

This frees up a lot of the energy consumed throughout the day to get where it needs to be. This just happens to be the place you likely want it to be, and that is building up your muscles and giving you a generally stronger body, as well as repairing everything else. It’s the only time your body can really concentrate on healing.

The Mental Side

Woman looking sad in her bed

There’s more to this whole topic than first meets the eye when it comes to sleeping and exercise. These effects are not confined to a physical effect. A large amount of the benefits of sleep happen to you mentally too. Since exercise needs a healthy body and mind, this needs to be looked at as well. As most of us will know, it can really ruin your day if you have a bad night’s sleep.

It Affects Your Energy

Woman asleep at the gym

The most commonly seen mental effect that a lack of sleep will impose on you is a distinct lack of energy. Sleeping is when you give your brain time to recharge and give yourself time to process all the things that have happened throughout your day.

Of course, what comes with this is a refreshed and motivated mood a lot of the time. That can really make a huge difference to you sticking to your goals, thinking clearly and concisely and generally just having a good day rather than being grouchy and irritable.

Exercise is hard work at the best of times, and having that fresh feeling and a positive attitude really helps make it all happen. Don’t underestimate what sleep can do for your exercise!

And Your Hormones Too

Tired man with coffee in hand

Getting into the more nitty-gritty of a lack of sleep is a lot more in-depth too. One of the most complicated examples comes from looking at your hormones. When you sleep, your hormones go back into check so that you can function like a real person rather than just a zombie. Unfortunately, it does happen to people who aren’t giving themselves enough sleep.

You usually feel tired and often hungrier, too, as your hormones haven’t had time to be dealt with by your brain. It can cause all kinds of complications, and it’s genuine too.


Ill woman

With all of these factors affecting your brain, the results can be really varied. But, of course, not being able to function properly when you get out of bed is the least of your concerns as you begin to weaken as the day goes on.

Sleep deprivation leads to a weakened immune system, a lack of recovery, increased appetite, going right the way to anxiety and mood swings if the deprivation gets severe enough!

It really is vital if you want to make the most of your health, fitness, and exercise. For something so easy to do, it really is worth a little extra time to get you those golden 7-9 hours a day.

Just Before You Go, Though…

Tired couple

A word of warning.

Now that we have just spent all of this time telling you how important sleep is, we, of course, have to tell you the dangers of going too far and other things that you have to avoid.

Oversleeping can be just as detrimental to your health and your workouts as not enough sleep can be. You become lethargic and tired more often and end up missing chunks out of your day, which can be demotivational in itself, especially if it means you sacrifice other parts of your day, like exercising in the first place.

The way to get the most out of your sleep is, of course, to set a pattern. A good solid sleeping pattern will help you be less tired and more alert when you should be.

You’ll even find yourself waking up naturally rather than needing an alarm, and you’ll give your body the best possible chance to make the most of the time you spend in your bed.


Before beginning any exercise or nutrition program, consult your physician, doctor or other professional. This is especially important for individuals over the age of 35 or persons with pre-existing health problems. Exercise.co.uk assumes no responsibility for personal injury or property damage sustained using our advice.

If you experience dizziness, nausea, chest pain, or any other abnormal symptoms, stop the workout at once and consult a physician or doctor immediately.