Should You Exercise When You’re Tired or Sleep-Deprived?

Should You Exercise When You’re Tired or Sleep-Deprived?

(Last Updated On: April 16, 2019)

Should you exercise when you're tired or sleep-deprived?Once you’re committing to staying fit, you don’t want anything come between you and your workout. Even when you’re on a tight schedule, you find a way to fit in an exercise session. Fortunately, when you’re exercising at home, that’s not so hard to do.

Commitment to fitness is a good thing as long you keep the bigger picture in mind – your health. Some people become so committed to their workout that they exercise when they’re sick or exhausted after a night of too little sleep. To be fit AND healthy, it’s important to strike a balance. That means making rest a part of the equation – and know when rest is the best option. Here’s the question. If you’re exhausted from lack of sleep – should you work out when you’re tired and sleep-deprived? Find out why rest is the best option.

 Your Performance Will Be Sub-Par

Even one night of little sleep can affect your workout. A study published in the International Journal of Occupational Medicine and Environmental Health showed that reaction times decrease and performance on tasks like driving and operating machinery declines. Cognitive function suffers too. It becomes harder to make decisions and memory is impaired. Plus, sleeplessness increases sensitivity to pain. That means your workout will feel all the harder even when you aren’t working as hard as usual.

Another study showed that one night without sleep decreased performance during endurance exercise and participants had a higher perceived level of exertion. In other words, even though they ran a shorter distance than usual, it felt harder.

The take-home message? If you work out when you’re sleep-deprived or very tired, it’s unlikely to be a productive session.

Your Risk for Injury Goes Up

With your reaction time slower and thinking skills and judgment clouded by fatigue, your risk for injury goes up when you’re tired or sleep-deprived. Why risk an injury just to say you worked out? Better to rest and approach your workout with fresh enthusiasm because you’re rested and operating at peak efficiency.

It Negatively Impacts Your Immune System

It doesn’t take much sleep deprivation to cause problems. Even one night of poor or inadequate sleep raises cortisol levels. This puts a damper on your ability to fight off infection. Combine that with the added stress of a hard workout and you put yourself at greater risk for whatever virus happens to be making its rounds. When you’re exhausted, you need rest to lower your cortisol levels and get your immune system back up to snuff.

The Effects of Inadequate Sleep Are Cumulative

If the time you’re using to work out in an exhausted state cuts into your sleep time the next night, you’ll feel even less “perky” the next day. After being sleep-deprived for a few nights, your performance, cognitive function and reaction time declines even more. That means you could end up having several days of less productive workouts and be more likely to injure yourself.

It Interferes with Tissue Repair

When cortisol levels are high, it interferes with tissue repair and growth. In addition, anabolic growth hormone is released primarily during the deeper stages of sleep. When you’re sleep-deprived, it creates an unfavorable metabolic environment for growth and repair. Better to rest and get a good night’s sleep than further stress your system with a workout. This will only raise your cortisol levels further.

Other Reasons Sleep is Important

Sleep doesn’t just impact your workout and ability to build muscle, sleeping less than 7 hours a night has been linked with a greater risk for health problems like type 2 diabetes, heart disease, hypertension, an increased risk for weight gain and higher mortality. Plus, it has a negative impact on mood. Who doesn’t feel grouchy and a little anxious when they haven’t slept?

The Bottom Line?

When you’re exhausted and slept very little the night before, take a rest day and let your body recover and stress hormones normalize. If you work out in an exhausted state, your workout won’t be as productive, tissue repair will be compromised and you’ll increase your risk for illness due to decreased immunity. Plus, you probably won’t work have a very productive workout. Maximize your nutrition and give yourself a day to rest and recover. It won’t negatively impact your fitness level. It’ll help you be fitter and healthier in the long run.



Int. J. Occup. Med. Environ. Health. 2010: 23 (1): 95-114.

Eur. J. Appl. Physiol. 2009 Sep: 107(2): 155-61.

Washington State University. “How sleep affects sports performance” “Insufficient Sleep Thwarts Weight Loss Efforts”

Sleep. 2010 May 1; 33(5): 585–592.

15 thoughts on “Should You Exercise When You’re Tired or Sleep-Deprived?

  1. yes…I can truly relate to this because of our recent move. I have never been more exhausted since moving our family 800 miles. The lack of sleep and getting settled have sapped the energy from training the way I am used to. I managed to sneak in a training session and was rewarded with a nasty cold. Inadequate sleep and hard training do not mix!

  2. I agree with Krista….I used have the mentality that it was best to exercise no matter what. I am learning that everything in moderation is actually the key….while exercise is amazing and has so many benefits, if you don’t allow your body to recover during adequate rest (sleep), it is actually counteractive!

  3. If i were to follow this bullshit advice then I might as well quit working out. I dont care about my health anymore, my body wont allow me to sleep so i dont have a choice. Im only able sleep on the weekends and I cant lift two days a week so I will continue lifting on 3 hours of sleep a night.

  4. im 18 yrs old from ph, im 50 kg 5 ft. im new here i only sleep 5 hours a day bec. of tight schedule, so is it okay to work out even u lack of sleep? Help.

  5. Sometimes I will have enough sleep during the day time and later in the night I might feel a little healthy and will not find sleep all night until early morning . Maybe categorically. Sleeping from 6pm until 10pm and stay all night awake then fall back to sleep at 6am until 9am then wake up and prepare my exercise. . Couldn’t be dangerous ??

  6. I am a chronic insomniac. I fall asleep easily, but it’s rare that I ever sleep through the night. I wake up some time after midnight and sometimes I don’t fall asleep again. Sometimes I feel okay. Sometimes I’m exhausted. Either way, I always exercise because if I took a “rest day” I would never work out. I think better advice would be some advice on the best forms of exercise to do.

  7. I feel that this was a good read. Although it may not be suited for all, it’s still considered sound advice. Honestly, there’s something out there for everyone, this may or may not be for you, but it doesn’t make it wrong. Thanks for posting this!

  8. My question is, what if you can’t sleep on all days? Not because of a tight schedule. But simply because you lay down and your brain just doesn’t go to sleep. It’s like you just get into bed and wait, and when you get tired of waiting you look at the clock and realize it’s 3:00 and you have to be up 2 hours and you’ve just laid down in bed and waited without your brain actually sleeping.

    And even worse? You try to ask this exact question and get nonsense answers like

    “Have u tried carbs b4 bed?”

    “Have u tried melatonin or benadryl?”

    Like wow. Thanks. I’m cured.

    I’ve tried every drug in the book and my sleep specialist has no idea where to go next (and don’t you think of little tiny solutions like benadryl worked I would be seeing a sleep specialist in the first place? )

    Look I know that not being able to sleep makes everything fitness related go kaput.

    But if I just stop training period, I’ll lose all my muscle, gain a ton of fat, and all and all be in a worse situation then when I was.

  9. Genius advice, these people who are saying they don’t have time are obviously doing something wrong in their lifestyle or they really do live on a tight schedule. I find a way to make it work though and I also live on a fairly tight schedule. Good article and one hundred percent the truth.

  10. My problem is that I am a shift worker with a wife who won’t let me sleep during the day. Basically it is extremely common for me to get very little sleep. She tries to get me to work less but complains that we don’t have enough money. Yes she has mental health issues.

    I used to regularly work out at the gym. Indeed the girlfriend I had immediately prior often said something about how she loves my body and another said that I should be grateful for my body. Others had also made flattering remarks that probably related like “stud” and “real man”. I had been working out since high school and even accused of taking steroids.

    I have always taken the approach of not working out if I am really tired from lack of sleep and suspected what the research has found. However in my current circumstances it has meant not pumping iron for a very long time I have started to wonder if I would be better off working out anyway. Even if I do get sleep housework, looking after my 4 kids and my wife’s hostility to catching me out exercising create a barrier. I am lucky to infrequently sneak in a workout swim for a few minutes or some push-ups. The stars just don’t tend to align so I have often thought about just exercising while dead tired.

    Unfortunately Google did not tell me what I want to hear. Thanks for the advice anyway.

  11. PS I am not just thinking of my health. There are practical reasons I want to be in shape. I work as a bouncer. I would explain further but have already ranted too long and I am sure readers can connect enough dots to get the idea.

  12. Yeah I feel very tired when just a few reps or 10 min hiit without a proper good night sleep

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