Updated: Apr 18, 2020
By Wageningen Beasts
We probably all know the good feeling during exercise. Either we are in the gym lifting weights to become stronger, bigger and fitter, or we are running or cycling outside or practicing any performance sport. All of us who are very dedicated to training a lot experience this positive feeling during our training and a feeling of satisfaction afterwards. Exercise makes you feel confident in your body and makes you stress free. For those who train every (other) day of the week probably also know the feeling of not exercising for a couple of days in a row. This gives a feeling of restlessness, perhaps makes you a bit down, while being impatient to train again. For some people not
What defines addiction? Like any other term, phenomenon or condition there are countless definitions. Thus, while one definition may refer to addiction, another might not. Therefore it is always difficult to come to a conclusion and reach consensus. However, a distinguishment can be made between dictionary definitions and clinical definitions. Where dictionary definitions shortly and broadly describe something, clinical definitions are elaborate and detailed. Hence, in a clinical situation such definitions are needed to establish whether a certain disease is present or not. Hereby, there may be a difference in what the public refers to as an addiction compared to what a clinician would refer to.
Let’s start off with the following definition regarding addiction by the Cambridge dictionary: “The need or strong desire to do or to have something, or a very strong liking for something”. By means of this definition, exercise could be an addiction. The word addiction has quite a negative undertone, but when looking at this definition, is it really? Is it bad to have a strong desire for and liking of exercise? No, probably not. An exercise addiction in light of this definition seems neither negative nor positive. It’s just a matter of liking.
Another definition states addiction to be “a persistent compulsive use of a substance or action known by the user to be harmful”. Knowing that exercise is beneficial for human health, exercise would not be an addiction according to this definition. This definition mainly implies addiction to substances like drugs.
A medical definition, from the American Society of Addiction Medicine, regarding addiction states the following: “Addiction is a primary, chronic disease of brain reward, motivation, memory and related circuitry[…] This is reflected in an individual pathologically pursuing reward and/or relief by substance use and other behaviors. Addiction is characterized by inability to consistently abstain, impairment in behavioral control, craving, diminished recognition of significant problems with one’s behaviors and interpersonal relationships, and a dysfunctional emotional response […]” Note that all of those definitions acknowledge that behaviours, in addition to substances, potentially lead to addiction! Still, only gambling is officially recognized as a behavioural addiction as of yet, though internet and food addiction are vivid areas of research [2,3]. A clinician would hereby be careful to diagnose an excessive exerciser as an addict. Some aspects of this definition – such as the pursue of reward, inability to abstain (or stop) exercising, craving and possibly more – might hold true for exercise, but these are much less severe than when compared to a substance (or gambling) addiction. These aspects translate to a physical or mental dependency on exercise. This would mean that when the use of for example a substance would stop, the addict would suffer physical or mental consequences, also referred to as withdrawal symptoms. So when someone is used to exercising very often and suddenly stops doing this, he or she would probably experience some negative withdrawal symptoms. These are different for every person. While some may not experience these symptoms at all, others might become depressed, and everything within that spectrum.
During exercise, dopamine and many other chemicals such as endorphins are released in the brain. All these hormones and neurotransmitters lead to increased euphoria (happiness), reduction of anxiety and increases in pain threshold. Dopamine and endorphins are the feel-good neurotransmitter that play a role in the reward center of the brain. From eating delicious foods to winning a game and taking certain drugs, dopamine is the chemical that make us want it, and endorphins the one that makes us enjoy it. Without dopamine, you wouldn’t be stimulated to eat dessert after you are already satiated once you finished a two-course meal. Dopamine makes us repeat the actions that lead to its release in order to get the feeling of happiness again. Endorphins inhibit pain signals and could give a feeling of euphoria (a well-known example of this is the runner’s high). Endorphins act on opioid receptors. The opioid receptor works like any other receptor: it is plastic, meaning that it can change. Receptors can adapt to a changing environment by increasing or decreasing in number and also by becoming more or less sensitive, depending on the amount of substrate (in this case endorphins) that is present. We probably all recognize this in caffeine: when you hardly ever drink caffeine, you get very energetic after drinking one cup of coffee, but when you drink it more often you need more cups to get the same effect. This receptor desensitization (becoming less sensitive to stimuli and needing more of a stimuli to reach the same effect) also occurs with the opioid receptor. When one exercises very often, more endorphins are released on a daily basis than without the exercise. One becomes used to these higher levels of endorphins. Suddenly stopping with exercising daily would thereby result in a ‘blue Monday’: a lack of ‘happy hormones’ that makes you feel down. This could cause a physical dependence of exercise.
However, like stated before, an exercise addiction is not the same as an alcohol addiction. Where exercise is healthy for the body, excess alcohol is detrimental. So according to the definitions of liking or dependency as a criterion of addiction exercise can be an addiction, but not according to the clinical definition, nor is exercise harmful to the user. So is any dependency on something by definition an addiction? Are the things that stimulate dopamine and endorphin release in the reward center of the brain addictive? If you love listening to music and would suddenly stop having music in your life, would that be considered an addiction? Probably not. Or if you would have problems with abstaining from the toilet which results in a bit more than minor discomfort…
One might say that in general something is not an addiction as long as there are no negative consequences. Does this mean that as long as one just exercises frequently without any adverse mental or physical effects, exercise is not an addiction? We already know that clinically speaking, exercise is probably not an addiction. However, if at any point exercise has adverse mental of physical effects, can it be considered a sort of addiction or compulsive behavior? One review that looked at people who are exercise dependent found that compulsive exercise is associated with eating disorder pathology, perfectionism, neuroticism, narcissism, and obsessive compulsive traits. This doesn’t mean that anyone who exercises a lot will get these problems or traits, but it means that these problems or traits occur more often in an exercise dependent person that in an exercise independent person. It might be that people who are more likely to get these traits become exercise dependent more often than other people. It might also be that an extreme form of exercise triggers these problems or traits. However, this topic of research is still behind, due to the lack of research and methodological problems. If these problems or traits are not present we probably tend to conclude that exercise is not harmful, but is that true? Would there be a realistic situation that could occur in any of us where an exercise dependency becomes harmful?
When the consequences of exercise become negative There seems one possible and logical situation where exercise dependency has negative consequences: when one is not able to exercise anymore, of which injuries are the most common cause.
There are two problems regarding injuries with exercising a lot. First of all, exercising a lot could lead to training too much and thereby an increased risk of overuse injuries. Knowing how to train safe and smart could help a great deal with injury prevention, but there is always a chance on an accident. Secondly, exercise dependency makes one want to train often without skipping a training. It is therefore difficult to get enough rest to recover and to rehabilitate steadily without overtraining. One study that nicely illustrates this looked at interviews with physiotherapists, who had treated injured people with an exercise dependency . These therapists stated that the largest problem in treating these people was the low compliance when they asked them to exercise less. In other words, recovery from their injuries was hampered by the fact that they were not able to abstain from exercising.
Mainly this last aspect complicates the whole injury situation. Rationally one knows to take it easy in order to recover, but often this is too difficult. One ends up doing too much, resulting in a worsening of the injury, leaving you at the end and beginning of a vicious circle. One could stay within this circle for quite a while during which the situation keeps spiraling downward, until one finally realizes: it can’t go on like this. Meanwhile, the situation has hit rock bottom, where exercising (daily) has become impossible. In addition, daily life has become a struggle: walking, standing, even sitting causes pain. The feeling of missing a normal training becomes stronger and stronger. The body starts to become weaker and less muscular, stress increases, and one misses its most important outlet. Feelings of stress, anxiety and depression increase. At this point one wonders how much he would give to get out of this situation. Looking jealously how others are exercising like ever before, wondering why they can while you can’t. At this point you realize: I show signs of addiction. Which is just like what happened to me.
My personal experience I wrote this article because I found out for myself how addicted I was to exercise while I had been injured for a very long time. I suffered from a back injury for three years. The paragraph above roughly describes the development of my injury. I was in this downward spiral where I tried to train, ending up worsening the injury and the situation, after which the circle started again from the beginning. I quickly started to notice the injury in my daily life. I couldn’t walk for 20 minutes without noticing it, the same went for sitting. Standing was even worse. It caused me stress. There were moments I felt depressed (depression is a condition from which I did not suffer and I don’t want to speak lightly of it, but you get the point). I couldn’t enjoy the simple things anymore, because I was too distracted by the injury. I had been to six different physiotherapists. All of them were able to help me in the beginning, but after ending up in another downward spiral, they did not succeed in lifting me up from it again. At one point, it was so bad I couldn’t even go to the supermarket and do groceries anymore. It was the first year of my master, and it started halfway the first year of my bachelor. At this point I was often thinking about doing an internship in the next year, requiring 9 to 5 attendance. How would that on earth be possible, when I was laying down in bed half of the day? Let alone getting a job after my internship?
In the meantime I had been to so many physiotherapists, I started losing something much more important than my strength, fitness and muscle mass I had been working on for years. I started losing hope. I always thought at some point in my life I must recover from the injury, naturally. It made sense that this was a temporary thing and that it must go over at some point, but now I started to lose that confidence. If it had to end at some point, it first should be preceded by change or improvement, but improvement was not coming. Therefore, I gained the mentality to try anything that would give a slight chance of improvement. Someone recommended a physiotherapist who had helped him before. I did not have much confidence that it would help, but I went anyway.
At the beginning of every first session with a physiotherapist, the therapist will ask you to explain the situation and the symptoms of the injury. Like any other time, I explained in a mere 10 minutes what was going on. To explain the whole situation I would need about a day or write a whole book, but I did the best I could to give a good depiction of the situation. I told about all the advice I had been given by previous therapists and that I took all their advice to heart by doing all the required exercises, stretches, and any other possible beneficial action on a daily basis. Somewhere in the middle of my story he interrupted me and said “what exactly is the problem? You are not in great pain, your back can make all movements without problems, nothing seems to be wrong with your back. All you seem to have is some feeling in your back. You know, I think all those physiotherapists have driven you crazy: “Pay attention to this, pay attention to that, keep this straight, don’t forget that”. Just let it go. Just move on.” And so his speech continued for a while. Within half an hour I stood outside of his practice. After three years I found out that the problem had grown in my head. I was so intensely focused on my injury that anything I felt in my back caused me anxiety. Any stimulus would tell me something was wrong, that I was exhausting my back, that I had to lay down. This pattern had caused me to become so inactive and not used to moving, that it made sense that any movement would result in some feeling in my back. It made sense that when I would walk for 20 minutes I would start feeling my back, because I was not used to it anymore. I misinterpreted the stimuli since I didn’t know the reaction of my own body anymore. The day prior to the visit to this therapist I was not able to go to the supermarket and do groceries. This day I went cycling and walked for over half an hour. The week after I started exercising. I could again go out on a trip, visit family, go on a weekend trip. All things I couldn’t do before without having stress and anxiety, without enjoying them, I could now do again. It felt like my life has stood still for three years and I could start living again. Nowadays I am no more limited by my injury and I am doing my internship from 9 to 5.
In conclusion I experienced for myself the huge impact of restraining from training after exercise dependence. From physically feeling down and stressed to mentally seeing everything I worked for disappear. If I would have to answer the question “Is exercise addictive?” I would say that it can be considered a small addiction, even though clinically it is not recognized as an addiction. However, the purpose of the article was not to quarrel about definitions or only show scientific articles, but I wanted to show the human perspective, hence I called this an opinion article. I would say that if exercise would be considered addictive, it doesn’t have to be a problem. Like anything or any activity that brings us joy, exercise can brighten our lives as long as it doesn’t get out of proportion. If your whole world does not evolve around exercise, it wouldn’t be unbearable when suddenly exercising wouldn’t be possible anymore.
I would just advise to sometimes stand still and think about the transience of life. One day we will be old and our exercise performance will decline, so it should not happen that we lose our happiness when we get older. Realizing this from time to time will bring us perspective on what is important in life. Similarly, something detrimental could happen to us at any moment in life. When we are aware of this, we will be prepared and able to deal with it when it happens.
Always wanting to lift more weight, to get stronger, to be fitter, to look better is something you strive for when you are training passionately. However, at some point we must be satisfied with where we are. Enjoying what we have without always wanting more is an undervalued capacity nowadays. When we think in light of this about the endorphin story again, we know that exposure to more endorphins desensitizes the receptor. Always wanting more does therefore not work. When you get more, the next time you need even more to stay happy. Finally you would end up drinking 10 cups of coffee a day. A man who wins the lottery is thrilled of excitement one day, but this effect slowly wears off and in the end the money didn’t buy long-lasting happiness. It becomes boring. Similarly, this can be compared to a phenomenon called muscle dysmorphia (or in bro terms ‘bigorexia’), during which people feel like they are not muscular or can only see their shortcomings, even though these people are very ripped. It’s programmed in our brains and society to want more, but wanting more is not possible every single day. Happiness without sadness doesn’t give happiness. You can’t be happy every moment of the day during every day of the year. In our current society we have the idea that we should always be happy and when this doesn’t happen we are afraid that we don’t enjoy our lives.
Maybe our opioid receptors need a day off every now and then. Just once in awhile, a single day to not experience much joy. To stay inactive. To rest and sensitize. So the next time they get a glimpse of happiness, they take the opportunity to enjoy it to the fullest. And maybe so should we.
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