Miles to Go Before I Sleep: Running-Induced Insomnia

It might be all the miles or even just thinking about the miles that’s keeping you from falling asleep.

Hard training is draining! Running miles after mile on top of leading the rest of our lives should leave us spent by day’s end, but sometimes that very activity that’s causing us to be so tired can prevent us from sleeping. Really! There’s this thing called running-induced insomnia.

“What!” you might be thinking, “isn’t exercise supposed to make you tired and want to sleep more?” It’s supposed to, but it doesn’t always work that way. 

It turns out that running, or any exercise with high levels of physical exertion, can induce insomnia. I had mild insomnia as a child (actually still do). In high school I read the signs for insomnia are stuff like taking longer than an hour to fall asleep. I was shocked that there were people who could fall asleep in less than two hours after lights out.

Several years later when I was in graduate school, I started exercising more to battle excessive weight gain. Under the guidance of a coach, I learned for the first time how to exercise properly and how to actually exert myself. I found that by engaging in moderate levels of exercise three times a week, I fell asleep quickly and also stayed asleep.

Once I began experiencing what having a full night of sleep was like on a regular basis, I was amazed by how much more well-adjusted I felt! I quickly realized that exercise was a key component to my sleep-health when I quit for a little while. After making that connection, it was clear to me that I needed to exercise to sleep well. Except when I didn’t.

During marathon training, the cure was also the cause of the condition. As the weeks of training progressed and intensified, I found myself once again lying in the dark unable to sleep. It took me a while to figure out what was going on. It started about six weeks into training and at first I had insomnia 1-2 times per week, but over time it progressed to 4 or more times per week!

I wasn’t running every day and shuffled my off days each week, so it took me a while to figure out the connection between running and insomnia. At the very tail end of marathon training, I remember lying in frustration, wondering, “Why can’t I sleep? I ran today! I should be exhausted!!!!” Then ding! I realized that the last time I couldn’t fall asleep was after a run and the time before that, and so forth. But why was this happening? I decided to investigate!

What Causes Running-Induced Insomnia?

Insomnia Flickr Commons Image by Alyssa L. Miller.
Not being able to sleep is the WORST! Flickr Commons Image by Alyssa L. Miller.

While a number of athletes have experienced exercise-induced insomnia, the actual cause for the insomnia induced by exercise is not well known. I decided to take a deeper look at each possible cause to figure out why running was causing my insomnia. I figured my research my help you. So here are the possible causes of running-induced insomnia and also a few tips for prevention.

Exercising intensely before bedtime:  Exercise causes the core body temperature to rise, which makes it difficult for you to sleep. Right before we fall asleep, our core body temperature drops, so some scientists theorize that exercising before bed can prevent our core temperatures from dropping, keeping us from falling asleep. As for the science? The jury’s still out: the results from studies investigating this belief is mixed at best.

Since I usually exercise in the morning, exercising before bedtime wasn’t applicable to me, but if you notice you can’t fall asleep if you run later in the day, it’s an easy fix – run earlier!

Anxiety about running: Anxiety is a very common cause of insomnia in all people, and runners are not immune. If you find yourself tossing and turning while thinking about running when you should be sleeping, there’s a good chance anxiety and worrying about running is the cause of your sleeplessness.

If there’s anything you need to know about me, races and goals are not something I worry over, so this probably isn’t my issue. However, if you think your worries are keeping you from sleeping, try to unplug and read a book, stretch, or practice mindfulness techniques to relax before bed. In fact, try to make the hour before bed a run-free time and redirect your attention from anything running-related to, well, anything else!

Nutrition/glycogen issues: On a forum, some people who follow a low carb diet swore that they slept better after eating some carbs before bedtime on a day when they did intense exercise because of glycogen depletion. I ruled this one out for me because I always have eaten plenty of carbs, but it might be worth experimenting with eating more carbs before bedtime, especially after longer harder sessions.

Over-intensity of training: High levels of physical exertion causes your body to release a cascade of different hormones. Of all those hormones, cortisol is the likely culprit when it comes to insomnia. Cortisol is important for glucose regulation, but it plays a role in the sleep-wake cycle. After exercise, levels of cortisol rise as a function of intensity and fitness.

Initially I doubted this was the cause of my insomnia because I was using the Run Less, Run Faster training program and ran less than 30 miles per week. 30 miles per week isn’t very much compared to most marathoners around here. However, as Salty discussed a while back, overtraining is very specific to you and what your body can handle.


The night of my goal fall marathon, I laid awake for hours, not because of the excitement of finishing my first marathon, but because of running-induced insomnia. A week after Wineglass and going back to my usual running habits, I now sleep deeply and fitfully. This doesn’t mean a future marathon is out but I do realize now that I need to be careful about planning and executing a training plan so that I am able to sleep.

Miles to go before I sleep, 
Slumber, I’d like to keep.

Have you ever struggled with running-induced insomnia? If so, what do you think is the cause?

I'm an academic, a runner, and a New York cliché. I write about the science of exercise, training, and the culture of running. My current goals are a sub-23:00 5K (achieved on 4/22/17 with 22:48) and a sub-1:45 HM (achieved on 10/1/17). Now what?

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  1. Good review of different causes of insomnia. Having been insomniac most of my life, much anxiety and stress-induced, I notice it increases when I’m planning a longer or faster or different type of run the next day…I try to write notes about the morning’s run, tell myself it’s only practice, anything to kick it from my mind. Hard to do!

  2. Insomnia was a huge issue for me when I was dealing with overtraining. I was SO exhausted, but I could not sleep. I’d get up to run at 5:00 AM, come home and collapse on the couch (wouldn’t be able to sleep, though – small children to take care of). I might be able to get a nap in the middle of the day if I was lucky, but then, no matter how little I’d slept the night before, I’d hardly sleep at night, especially if I did a hard workout that day. I noticed a lot of times when I’d do hard workouts, I’d feel dizzy after and my hands would tremble. I’d feel so unbelievably tired, but then lay awake all night – looking back it was an overstimulated nervous system, clearly. Anyway, the point is, that if running is causing you insomnia and it’s not because you’re worrying about running or running 5 minutes before bedtime or whatever, BACK OFF. BACK OFF RIGHT NOW. Seriously. Particularly, tone down the hard days.

    Now that I’m running just for fun, I’m sleeping again. ALLELUIA!

  3. I’ve always had trouble getting to sleep and running (along with a very strict schedule…oh wait, not anymore, thanks baby JB) has helped me a ton with that. I notice whenever I take time off from running or even run just minimal mileage I have a harder time relaxing and falling asleep.

    Like Salty said ^^ I’ve also had some sleep disturbances when significantly increasing training load, though fortunately not for long.

  4. Great article!! I’ve had insomnia problems for years, running actually helped it for the most part. Just last week, though I decided to do my strength-training at 10:00 pm. Dumb move.

  5. At least someone else here has insomnia. But in my case, I don’t think it is the running. Insomnia persists… during marathon training season. During recovery. During time off. It showed up one day and then just never went away. I just don’t think it is the running.

  6. When I was healthy and young moderate exercise always helped me sleep, even close to bedtime. I managed to damage my liver with antibiotic drugs and I then developed insomnia after training, especially squats but all other activities where muscles worked hard. I believe an important part of insomnia is the function of the liver and kidneys to metabolise and excrete the hormones, lactic acid, ammonia which are created during activity. A poor liver will mean higher levels of these chemicals in the bloodstream for longer after activity.

  7. Your story sounds vaguely similar to mine. I survived most of middle school and all of high school functioning on about 4-6 hours of sleep a night. That only improved during intense, pre-season practice weeks for soccer and track and field.
    Now that I’m a 30-something adult, genetic and chronic health issues have become apparent and I’ve been struggling to stay fit and active despite severe pain and chronic fatigue.
    I’ve been baffled and have stumped doctors with my activity induced insomnia. The more I walk, work out (gentle, short work outs) or participate in physical therapy, the worse my ability to fall asleep and stay asleep get and the worse my quality of sleep becomes.
    Point of fact, I’m awake now because I’ve been too active all week and battling insomnia as a result.
    Thank you for doing this research and for writing this article! What a relief to know it’s not just me connecting two unrelated things or, ” imagining things.”
    Telling doctors, “the more I exercise, even just walking, the worse my sleep gets over time,” tends to cause them to look at you as though you’ve just sprouted another head.
    Maybe now I can figure out a solution!

  8. I don’t have problems sleeping on a regular basis during hard training, as long as I have a good wind-down routine and comfortable conditions, but I cannot sleep the night after a marathon to save my life, and after a half marathon it’s hit or miss. I’m generally fine after shorter races (except when I made the mistake of racing a 10,000 m that started at 9:30 p.m., but I knew what I was in for when I signed up for that!). I figure it’s an evolutionary carry over and my body thinks there is no way I would have run so many miles so fast if I weren’t in grave danger so it won’t let down. I haven’t figured out anything to remedy it, but I have learned that I always need the day off work after a marathon!