22 June 2013,

In the following investigation, researchers have determined that adolescent rats stand a greater chance of avoiding drug addiction if they engage in exercise, while also experimenting with ad lib access to cocaine. What this means for obesity related research, or even behaviour modification is explained below. Thank you for your time and interest in this post.

Of course I’m biased, but I find one of the most compelling aspects of science today is the psychology of appetite. By tracing the sensation of pleasure we feel when we eat, we can get a greater sense of the neuro- alchemy that occurs for other pleasurable habits. Let’s take shopping, or even drugs. Drugs seem to be the most efficient way to feel good. They are also the fastest way to lead to irreversible brain damage, financial ruin, impotency. You can weigh in on the consequences for that: my personal preference is abstinence.

Yet, speaking of transactions, the currency of pleasure is the subject of intense scientific research. If we can calculate the precise locations in the brain where pleasure resides, we may uncover an important vantage for understanding how to manipulate it. ‘It’ being pleasure, not drugs. In a way, this is how pharmacological innovation works: find a site in the brain, study ways to excite or depress it, and then calibrate doses of chemicals in order to address abnormalities (or re establish a perceived homeostasis) that is out of order, due to a variety of different reasons.


However, what can you do when flip a switch on so strongly, that it causes everything else in the brain to shortwire? This, in essence describes the problem with drug abuse: everything else pales in comparison with the pleasure associated with the drug. Particularly for people who are prone to becoming addicted to drugs. Drugs for one person aren’t the same for drugs for a person with a vulnerability for addiction. You could probably make this argument for food, too. Chocolate is pleasant for everyone, but for some people it’s particularly exciting. For those people who find these things really great, abstinence may work for the short term, but what about strategies for the long haul? What if you could dial down the pleasure so they didn’t seem so attractive?

Opinions vary on when or if we will find a pill based solution for too much pill popping. Or a food free solution to too much food. While I’m skeptical that we will ever find a pharmacological intervention for addiction, I am also hopeful about the strength of human will. And, an interesting suggestion growing in popularity is the idea that exercise may reverse some of the damage to the brain caused by drugs. The idea, is that physical activity may repair key areas in the brain that are responsible for relapse in drug and alcohol addiction.

…Before getting too excited about the possibility that the treadmill can treat a ten year coke habit, let’s look at some scientific studies. The evidence is interesting and makes a strong case for mandatory gym class amongst teenagers.

‘Exercise to reduce the escalation of cocaine self-administration in adolescent and adult rats*’ (2012). Shows how exercise can reduce cocaine self administration within rat populations, both in adolescent and aged groups. Researchers:

a. allowed rats to self administer cocaine for 5 hours a day, for five days.

b. trained all of the rats to wheel run

c. allowed half the rats access to exercise + drugs

d. and the other half drugs only

e. compared cocaine intake between groups after 16 days of training.


The study results show that adolescent rats who were able to run and take cocaine, actually ended up opting for less drugs. However, for those rats who could not exercise, their drug use went up. For adults, however, no amount of running reduced cocaine intake. It seems that if you acquire a cocaine habit at an old age, and you are a rat, you are destined to keep using if there is free access.

The results demonstrate that physical activity can have protective benefits to adolescents who learn to exercise in tandem with exposure to ultra rewards, like drugs.

Can you see where I’m going with this post? Exercise limits intake of one of the most pleasurable substances on earth among animals that have no ability for rational thought. Humans, have significant capacity for rational thought (go with me here), so additional excercise may enhance long term planning.

Maybe some further clarity. At its core, physical exercise diminishes the rewarding aspect of whichever substance is being abused. My logic, is that if P.E. has protective benefits for rats with cocaine, imagine what this could do to help you/me/ children avoid having too many chocolate bars.*  With increased frequency, we are learning that some of the most basic behaviours are the ones with the biggest health benefits. Eating well. Exercising.  Tragically, kids have huge exposure to drugs, and we all have massive exposure to ad libitum ultra unhealthy food thanks so much to very clever marketing.

With all of this information (there are a LOT of studies like this) you’d think we’d jump on the physical activity bandwagon with more gusto. Yet, many of us are still in deep denial about the fundamental importance of… gym class. It may be a dowdy proposition, but I really think we need to invest more hope for excercise, and less for pharmacological intervention. At least we know the former is a sure bet.


*A critical point is that we must rely on animals for this kind of study. We cannot manipulate humans with drugs, as it would be wrong to give someone a cocaine addiction in the name of scientific exploration. For this reason, we have to rely on animal models and research.

*Well more or less: the fine prints states that they were allowed to practice wheel running (or not) for 16 days. Then 10 days later they recorded behavior for the opposite conditions: so those rats allowed to wheel run and take coke were now only allowed to take drugs. The rats allowed only access to cocaine now had the use of both (drugs and exercise).



One response on “Can Exercise Fight Addiction? Adolescent Rats Say Yes…

  1. a friend recommend this to me, glad he did

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