Woman in bed struggling to sleep. Text on image: Are you getting enough sleep? Your fitness goals may depend on it.

How Sleep Affects Your Fitness Goals

bad habits goal achievement habits sleep sleep research sleep science success Jan 13, 2023

Despite what hustle culture may tell you, you aren’t a more accomplished human for functioning on less sleep. 

 If there’s one thing you’re going to commit to doing to improve your health, let it be that you sleep more.

 Sleep can help you with so many things, including:


  • Losing fat
  • Building muscle
  • Improving your mood
  • Increasing your cognitive performance
  • Enhancing productivity
  • Improving your relationships

You need to sleep more and sleep better.⁣

I get it, it can be hard to make sleep a priority when it feels like wasted time, but sleep is anything but a state of inactivity.⁣

 Our brains are busy while we sleep. Sleep is when memory and learning are solidified.⁣

 Our bodies are busy, too, because sleep helps our bodies heal.⁣


⁣Sleep Deprivation and Your Health


Sleep deprivation leads to raised inflammatory markers⁣ and lots of other not-so-good stuff. 

Research shows that sleep deprivation can impact muscle building, fat loss, and hormone health. 


How Sleep Affects Fat Loss and Muscle Building


In one study on sleep deprivation, fat loss, and muscle building, a group of participants, all of whom were in a calorie deficit, were randomly assigned to one of two groups. 

The first group slept for 8.5 hours per night and the second group slept for 5.5 hours per night.

The research showed that both groups lost weight, as they should have because they were all in a calorie deficit. 

However, those who slept more lost 55% more weight from fat mass, whereas those who slept less lost 60% more weight from muscle mass. 

So you’ll lose weight by being in a caloric deficit, but the amount of sleep you get will determine whether you’re losing body fat or muscle mass.



How Sleep Affects Your Hormones


As I mentioned at the beginning, sleep impacts several aspects of your health, including your hormones. 



The hormone leptin is responsible for telling your body when you are full. 

However, leptin gets down-regulated by poor sleep, which leads your body to believe it needs more energy than it actually does and elevates your hunger. 

Pay attention to your hunger next time you have a poor sleep, and you’ll likely notice that you’re reaching food more often than you do when you’ve had a proper night’s rest. 



Another hormone that is impacted by your sleep is ghrelin, which tells your body when you are hungry and need energy. 

If you don’t sleep enough, you end up with excess ghrelin, which leads to increased hunger, reduced daily activity, and fat retention because your body thinks you need more calories/energy than you’re getting. 


Human Growth Hormone (HGH)

Human growth hormone is the muscle-building hormone that is naturally produced while you sleep. 

Sleep increases blood flow to your muscles, which increases tissue repair and rebuilding. 



How Much Sleep Do You Need?


The standard recommendation to best support your muscle building or fat loss efforts is 7–9 hours per night. 

But, like everything else, this depends on the individual. The more active you are, the more sleep you will need. 

On that note, research presents evidence that strength training helps you fall asleep faster, have better quality sleep, and wake up less frequently throughout the night.

Lifting is good for your sleep, and sleep is good for your lifting!


How to Get Better Sleep


Okay, great, I’ve convinced you that you need to get more sleep, but now you want to know how you can level up your sleep game. 

Here are some ideas you can test out:⁣

  • Create a routine for yourself. Wake up and go to sleep around the same time every day.
  • Use your bed only for sleeping (don’t work in bed, don’t watch movies in bed, etc., though there may be one exception here)⁣.
  • If you’re having a hard time sleeping or falling asleep, GET UP. Grab a glass of water. Don’t keep lying there as frustration rises.⁣ 
  • And, of course, the usual: limit caffeine, keep your bedroom cool, dark, and quiet, no electronics near bedtime, and get regular exercise⁣.

Bonus Sleep Tip

One thing I never see anyone recommend is mindful awareness and acceptance. 

 Instead of fighting your “to-do list” thoughts at bedtime, accept them.⁣

 Acknowledge the thoughts, knowing they are important but will still be there in the morning.⁣

 Also, be mindful of your breathing, bring awareness to it, and try progressive muscle relaxation — I have a video on this.⁣

 When other thoughts crop up, acknowledge them, and then go back to focusing on your breath.⁣

 The research on mindfulness for insomnia is very compelling, so don’t *sleep* on this “woo woo” stuff, guys.⁣


Create Better Habits


If you’re looking to create better habits, whether that’s around sleep, your relationship with food, or your mindset, working with a coach can help. 

The team at KJO Coaching can help you prioritize your health, fitness, wellness, and mindset so you can spend less time worrying about what to eat or how to get enough workouts in. 

We take a highly-individualized approach to health, fitness, and wellness coaching because we believe that your health is about so much more than food and exercise, and what you need is different than what someone else might need. 

Click here to learn more. 


You can start creating better habits before you start a coaching relationship with us. 

Our FREE habit formula helps you determine which behaviors you need to change, when to do them based on your lifestyle, and how to fit them into your life based on your goals. 

Get access here!

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Garland, S. N., Zhou, E. S., Gonzalez, B. D., & Rodriguez, N. (2016). The quest for mindful sleep: a critical synthesis of the impact of mindfulness-based interventions for insomnia. Current sleep medicine reports, 2(3), 142-151.

Nedeltcheva AV, Kilkus JM, Imperial J, Schoeller DA, Penev PD. Insufficient sleep undermines dietary efforts to reduce adiposity. Ann Intern Med. 2010 Oct 5;153(7):435-41. doi: 10.7326/0003-4819-153-7-201010050-00006. PMID: 20921542; PMCID: PMC2951287.

Hi, I'm Kasey!

I coach, mentor, write, and teach with one main focus: Build strong bodies and healthy lifestyles, starting with your mindset.


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