Running Addiction: Are We Just Rats on a Wheel?

We’ve all made the comparison between running and drugs before, that ubiquitous term “runner’s high” refers to that rush of endorphins our brains release during or after a run. It’s that feeling that keeps us pounding the pavement in search of more.

We need our daily fix, we freak out if we can’t run, and we do all sorts of crazy things to fit the miles in, like getting up in essentially the middle of the night to run, missing out on girls’ night out, or skipping a shower … again.

But is running actually addictive like that? Do we love running or are we hooked on our own feel-good chemicals, chasing an ever-harder-to-reach high as the miles increase our tolerance, so we constantly need to go further, or faster, or on new terrain to obtain that same buzz?

The research is out there, and the answer is yes. That edgy, moody, fidgety feeling you experience if you’ve gone too long without running is called withdrawal.
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I Trained Rats

Back in my teaching years, I designed and taught a science class on animal behavior. We covered behavior in the wild, things like courtship to social behavior as well as ethical issues like factory farming. And then we dove into animal learning and motivation, covering both classical (think Pavlov’s bell) and operant conditioning (controlling behavior through consequences) in depth. The concepts in the class were applied in real life to a baby rat that each student received at the beginning of the term.

Using positive reinforcement like treats, and negative reinforcement like food deprivation, we trained the rats to perform five different behaviors: weight-lifting, long-jump, tight-rope, rope climb, and running the hurdles. At the end of the term, the top ten rats competed in the Iron Rat Competition, held over two days in the school gym, all vying for a golden cheese medal.

Operant conditioning teaches subjects that they will be rewarded for certain behaviors. In the case of the rats, my students saw that giving their rats treats after the rats performed certain behaviors, taught the rats to perform better and better: jumping farther, running and climbing faster, lifting more and more weight. The champion long jumping rat jumped over four feet between two platforms to get a treat.

The larger goal of this class went beyond how to train rats. It demonstrated how these theories applied to our own human capacity for learning, motivation, and addictions.

Is Running Addiction Real?

I was a newer runner back then, racing Boston as my students tracked me in Oregon. That was also about the time I went from runner to RUNNER as my miles and speed were on a break-neck upward trajectory.

Around the same time, a rat study caught my eye, because the researchers’ goal was to compare addiction to running to addiction to opioid drugs. Yes, those opioids, the highly addictive drug class that includes heroin, opium, codeine, oxycodone, among others.

Opioids mimic the endorphins and other neurotransmitters that your brain releases that make you feel gooood. Running releases these feel-good chemicals naturally, so the researchers wanted to determine if running is similarly addictive.

The Running – Opioid Rat Experiment

In a nutshell, rats in the control groups were housed in standard cages and were either food deprived and fed only one hour a day, or had unlimited access to food. Meanwhile, the experimental groups were housed in cages with running wheels.

The experimental group rats with wheels were further split into two groups: a food deprived group and an unlimited access to food group.

No matter how often they were fed, the rats with wheels all ran a lot, but also all voluntarily decreased their food intake and lost weight. The food-deprived rats with wheels increased their running time even more. What this suggested, is that the rats rather spend their time running than eating. The rats who were stressed from food deprivation ran even more to make themselves feel better. In fact, over time, the rats ran more and more frequently.

Once the rats got down to 80% of their starting weight, all the rats, including the running rats with wheels in their cages and the sedentary rats, were injected with naloxone, a drug that blocks the effects of opioids, including running-induced endorphins. When someone who is addicted to heroin takes naloxone, she immediately begins withdrawal even if she’s still taking heroin. What would it do to the run-loving rats?

Upon receiving the naloxon injections, the running rats, the ones with the wheels in their cages, experienced withdrawal symptoms similar to those experienced by heroin addicts, while the inactive rats did not. The rats who ran the most, the runner rats who were also food deprived, also suffered the worst withdrawal symptoms.

The running rats had increased their tolerance to their own neurotransmitters responsible for the runner’s high, as a result they had to run more to achieve the same high, and when were chemically “sobered up” they went through withdrawal.

The Drug Called Running

What did the researchers conclude from these results?

These findings support the hypothesis that exercise-induced increases in endogenous opioid peptides act in a manner similar to chronic administration of opiate drugs.

Translation: Running has similar effects on brains to heroin.

Running acts like a drug on a cellular and behavioral level, and it’s physically and behaviorally addictive. Over time we develop tolerance to running’s effect, and we also go through withdrawal if we stop cold-turkey, just like if we were a heroin junky.

Let that sink in for a moment.

The Running Addict

Does this ring true to our observations in ourselves and of other runners?

Does this sound familiar?

Runner runs, loves it, finds friends who positively reinforce and enable the running behavior.

Runner chases faster times, runs more and more miles.

Running becomes the priority over many other things, affecting the runner’s relationships, work, and other behavior.

Runner gets frustrated, edgy, or angry when she has a disappointing race, gets injured, or otherwise encounters obstacles to running faster, longer, more often, or even as much as she once did.

Runner continues running despite physical pain, burn-out, or dysfunction in the rest of her life.

Runner continues until runner cannot run and becomes depressed, irritable, and lethargic.

Runner seems to come around, heals, and starts back up healthier and with a better, more mature perspective, and then soon is clawing her way back to running all the time and pouring money and emotional energy back into chasing those big running dreams.

Really? Running Addiction?

Can something good for us be an addiction like a drug addiction? Yes. Addiction, according to the National Institute of Health, “has come to refer to a disorder in which an individual becomes intensely preoccupied with a behavior that at first provides a desired or appetitive effect.” A person is addicted to exercise when “many occupational, educational, or social activities are neglected, depression occurs when the individual does not exercise, and excessive exercise may lead to repeated injuries.” Additionally, it has been shown that running is often specifically used by drug or alcohol addicts as a substitute for their chemical addiction as they try to become sober.

So what’s my point here? To pour a big old buzzkill over your runner’s high? No, because I’m looking in the mirror here and pointing at myself, too. I got so high last year, until I crashed and hit over-training hard. I quit, cold turkey for ten days. Then swore this year would be different and I’d have a healthier attitude with no goal or plan.

Chasing balance and clarity.

The first six weeks gave me some clarity, and let me see how unbalanced I had become over the last four years. But my mileage has sneakily crept up, and I’ve started to feel like I need more. I’ve been moody, running long and doing doubles trying to feel better, impatient with my family, distracted, fidgety, even biting my nails again. Should I run a really fast workout? Do some more hills? Sign up for a race? Just one cheat race? Just one. Tiny. Race???

Or maybe I need an intervention?

Maybe not quite, but recalling my old rat study has given me some much-needed insight. I’ll stick to my goal of not racing this year, and read back on my teaching notes about extinction if I need a little help to stick with my plan.


It’s an insidious drug, running, because we think of it as a good thing. But anything in excess can tip the balance of “good for us” to not, even running.

Have you ever felt like you were addicted to running?

I'm an elementary P.E. teacher with a long-term, ongoing marathon addiction.The next big goal? Keeping up my BQ streak while aiming for a 3:10! I write about the not-so-glamorous side of running and fitting in serious training with a family while staying sane(ish).

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  1. I definitely would say running is my drug of choice. I think that having some sort of plan, whether it be train for a race or get faster at a distance, go longer etc, helps keep you from overdoing it. You do what is on the plan and that’s it. There’s no “oh, I don’t have a plan so I’ll just run whatever.” Because we as hardcore runners will use that as an excuse to run more.
    I think in addition to being a running junkie, i just enjoy moving my body in some way. So perhaps if I was unable to run (and when I have been unable to do so) I try something else.

  2. Back in, oh, 2008 or so, I was using running as a way to cope with a number of other issues in my life. My doctor point-blank said, less self-medicating via running, let’s try some anxiety medication. I had lost a lot of weight, developed a string of never-stopping muscle twitches … all sorts of things. In the end, I kept running but got divorced, instead.

    But yes, many of these ring very true!

    1. I can relate, definitely was a time where running was my self-medication but I dare say it’s been a long time since I regularly used running that way. Part because I eliminated some things from my life that were causing the need to self medicate, and part because I formed healthier relationships with other things that can help instead of just running.

  3. Some of this rings rather more true than I would like to admit. As someone who has been injured and not running seriously for several months, I can report that the “addiction” is not fading. But how do we define the difference between addiction and passion? I had a great chat with a friend yesterday who is a passionate bird watcher. He has planned many vacations around this activity. He was in fact planning to “sneak off” to see birds right after driving me to the airport. He thinks about birds A LOT. I guess it depends on whether our passion impinges on the rest of our life too much? How much is too much? Thoughts to ponder.

    1. Yes, it’s when something negatively impacts other areas of our life. There’s an invisible line that gets crossed and when the good thing starts doing more harm in our lives than good than we have a problem.

  4. I wonder if addictions in general are on the rise as a direct result of the fact we don’t move our bodies enough in day to day life. In the “old days” when daily life required significant energy output, and lots of movement regardless of profession, perhaps we were all getting our needed high just from daily life…. and we didn’t need to resort to things like drugs, alcohol, or exercise for the sake of exercise to get it.

  5. What I additionally found interesting about this study, is that by constantly upping our body’s feel-good chemicals through running we increase the amount of chemical our brains “need” to feel good, just like drug and alcohol addicts need more over time to get the same high. The other problem with that (besides we’ll need to run more to achieve the same good feeling) is that it affects the rest of our lives too. Meaning, the natural high you get from other aspects of your life over time won’t compare because those things still trigger the same old amount of neurotransmitter. Your runner’s high tolerance sort of deadens the regular high you get from normal life events, because when you feel good it’s the same brain chemicals making you feel that way. This level of addiction, in drugs and alcohol, is why you end up with people letting go of all other relationships and interests in order to pursue the one thing that can make them feel good anymore. Now, clearly, most of us aren’t going to get to that level of addiction, the same way most of won’t get addicted to drugs or alcohol. But people who tend to get easily addicted to other substances should be aware.