Can Running Turn Into Addiction?

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A recent study on addiction, withdrawal and running would lead any runner to ask this very question. The way the findings have been reported in popular media outlets essentially draws the conclusion that intensive running equals addiction. Aaron Stegner, research scientist at the Exercise Psychology Laboratory at University of Wisconsin, Madison, takes exception with this overly-simplistic view.

In the study, researchers at Tufts University housed one group of rats in an exercise wheel, while another group had no exercise wheel. All the rats were given Naloxone, a drug that produces immediate withdrawal symptoms. The typically-active rats demonstrated significantly higher levels of withdrawal, similar to those of drug addicts, than the inactive rats. Why? "Exercise, like drugs of abuse, leads to the release of neurotransmitters such as endorphins and dopamine, which are involved with a sense of reward," noted lead author and Tufts professor of psychology Robin Kanarek in LiveScience.

Sure, you seek a runners' high to keep you going and miss running when you can't fit it in, but you're probably not addicted to running. Here's why:

"The researchers haven't demonstrated an addiction, what they have demonstrated is a physical dependency," says Stegner. "It's the same as when a person is used to drinking coffee regularly and then stops. They have a headache and don't feel well. That's a sign of physical dependency, but not necessarily an addiction." This is where a rat comparison is problematic. In humans, signs of addiction also include an emotional and psychological component. Says Stegner, "We typically ask questions like 'Are you sacrificing time with your family or job for a chemical? Are you constantly thinking about the next dose?' Those aren't questions you can ask a rat," he says.

Now, he's not saying that running addiction doesn't exist. "I have no doubt that there are people who are addicted to exercise, people who do miss work and time with family to run. But it's not the case that if you run a lot it will lead to an addiction," Stegner says. "Yes there are people who are addicted to exercise, but it's very rare and not a real danger for most people. It's the last thing most people need to worry about," he continues.

What is interesting about the research is the withdrawal aspect, which has been confirmed by other studies. Stegner even conducted his own research on "habitual exercisers" -- people who exercise six or seven times a week for at least 45 minutes a day. In his 1996 study, participants were asked to abstain from exercise for five days and he found that they became more anxious and depressed when not allowed to exercise. "For regular exercisers who can't exercise, there is evidence to suggest that there is a chemical change."

The point of the Tufts study, which was published in the August issue of the journal Behavioral Neuroscience, was really to examine treatment alternatives for heroin and morphine addicts. The findings suggest that it's possible to substitute drugs with other behaviors, like running, that mimic that high. It's also helpful for those with mood disturbances and chronic pain, says Stegner.

The bottom line? Of all the things on your plate you need to worry about, running addiction is likely not one of them.

Read about another recent study that exposes the myth of the "runners' knee."