How much does sleep affect your fitness progress?

I am sure I am not alone when I say I’ve been told the importance of getting your “beauty sleep” many a time. It turns out that this is not just an old wives’ tale, in fact, sleep affects us positively in many more areas than just the beauty department. Today, I want to talk to you about sleep and how it relates to body composition. Unfortunately, sleep is one of the 3 golden rules to an incredible physique, yet it is the most overlooked factor; in many cases, it doesn’t even make top 10 on our lists. We need to stop prioritising skinny teas and fat burners and start prioritising the amount of time your head is on a pillow. 

The 3 keys to a tight and toned body are sleep, nutrition and training. You can train all day, every day, eat the most nutritious foods and take all your vitamins, but it won’t offset insufficient rest and sleep. It is my hope that by reading the following you gain important insights into sleep and begin to implement a better sleep schedule for yourselves. 

THE LOW DOWN:

Why do we need to sleep? Sleep plays an essential role in the following functions:

  • Metabolism

  • CNS (central nervous system)

  • Endocrine (hormones)

  • Immune

  • Cognitive 

  • Digestive

  • Muscle and tissue repair

As well as so many other vital bodily functions. For those of us who are actively trying to change our body composition, sleep plays an integral role in biotransformation via recovery, muscle growth, strength, appetite regulation and protein synthesis, digestion (assimilation of nutrients) and gut health (digestion, bloating and water retention etc).  

When we are sleeping, our body has some quiet time; it is no longer busy expending energy on the digestive and cognitive functions that need to happen whilst we are awake, so it able to redirect that energy in to repair our muscles, replenishing our immune system, replacing damaged and cells, restoring hormones to normal levels and so on.    

A VICIOUS CYCLE FOR BODY COMPOSITION:

Let’s look at the picture as a whole as I am sure some of you aren’t yet convinced. Let’s say you’ve had one or more bad nights sleep in a row. How do you feel? Tired? Yep. So how is the gym looking to you today? Not as appealing right. I bet those cravings are peaking too… so adherence to your diet or macros is questionable. Does a lack of sleep directly make you gain fat overnight? No. But what it does do is biologically make it harder for you to make progress via impacting training and diet. 

When we don’t get adequate sleep our primary hunger hormones; leptin and ghrelin get thrown out of balance. Ghrelin (hunger hormone) increases which makes us want to eat more whilst leptin (satiety hormone) decreases, so we never feel satisfied and our cravings go through the roof.  Essentially, what can end up happening is your increased hunger and lack of satiety even when food (calories) is coming in, makes you over consume, thus you’re no longer in a deficit. In order to drop body fat, we must be in a deficit.  Lack of sleep also has a dulling effect on our frontal brain cortex which affects our decision-making skills. Mix that with low leptin and that’s a recipe for disaster. Those donuts you can normally resist? Not today my friends. 

On top of hunger hormones not being in your favour, a lack of sleep can severely affect energy, mood and motivation. Poor sleep can lead to a large decrease in NEAT levels as you don’t have the energy to move as much through the day as well as reduced strength and intensity output in the gym, if you have motivation to go at all. 

You can now see how over consuming calories, plus a decrease in overall activity for the day can result in a backwards step for that day. 

Another hormone that is greatly affected by sleep is cortisol. Cortisol is one of our stress hormones and when we don’t get enough sleep, our bodies become increasingly stressed.  When we experience poor sleep cycles, cortisol stays elevated which can negatively impact body composition in a number of ways. Cortisol can inhibit testosterone (which we need to build muscle) and raise estrogen and insulin levels. All of these can result in us feeling “watery” or “puffy”, anxious and irritable. 

SLEEP LIKE A BABY:

I understand that getting enough sleep is hard enough to factor in, let alone getting in good quality sleep. Quality sleep meaning that we are staying asleep and having full sleep cycles each night. I am going to share with you my top tips to sleeping like a baby, below.  

  1. Set A Sleep Schedule. Having a sleep schedule ensures that your body runs on a proper circadian rhythm. What this means is that your body get used to falling asleep and waking up at the same time each day. To start your body off on the right foot, you want to go to sleep and wake up at the same time each day.  As a result, you’ll fall asleep faster and rise with more energy. 

  2. Bedtime Ritual. Each night complete a “wind down” routine that you find calming. Each person's evening routine will vary; some people read, meditate or journal, others have an evening skin routine which relaxes them, other people stretch or bath. Whatever appeals to you, create a 30-60-minute pre bed routine so your body begins to form the habit, soon enough it will begin to know that when you start this routine, it is time to get tired and you’ll sleep like a baby. 

  3. Avoid caffeine after 12pm. 

  4. Sleep Space. The look and feel of your bedroom plays a greater role in your sleep cycles than you may assume. For a perfect night's sleep, keep your room reasonably cool and have it as dark as possible. White noise also helps so have a fan or aircon going. 

  5. Blue Light Blues. No screen time 1 hour before bed; that means phones, laptops and tvs out of the bedroom.  

  6. Write it down. You know that feeling when you are all relaxed, ready for bed but as soon as you jump in the sheets your mind starts racing? You are not alone. What I find really helpful is making lists and journaling before bed. Before I put my phone away for the night I organise everything I need to do for the next day and write down and pressing thoughts or troubling emotions I have. This way I feel like it's on paper so it doesn’t need to be trapped in my head. I don’t have that anxiety of potentially forgetting anything either as it is all laid out for me. I also like to jot down some gratitude points that occurred over the day do I end my day with a positive, grateful and open heart.


So there you have it, if you want to improve your body composition we need to be hitting each 3 sectors of diet, sleep and training with equal amounts of love. Getting between seven and nine hours of quality sleep each night is optimal for wellbeing, immune function, hormonal support, cognitive function and body composition changes.