Psychologists from Tufts University in Boston found in a recent study that it might be possible to substitute drug-taking behavior with running, an activity that produces a natural high.

“Being addicted to running doesn’t have the negative consequences of being addicted to something like heroin,” said lead researcher Robin Kanarek.

In the study, which appeared in the August issue of the journal Behavioral Neuroscience, researchers observed the withdrawal symptoms of physically active rats and found that they exhibit similar symptoms to rats that were addicted to morphine. Kanarek said the findings are applicable to humans because rats and people have similar neural pathways.

Leon Hoffman, 70, a downtown Chicago clinical psychologist who has run over 60 marathons, said that running can provide natural anti-depressants. However, it can be harmful to a runner’s mental and physical health if it becomes an addiction.

“A sense of well-being does occur with a great amount of running,” Hoffman said. “But with the same token, when you interrupt that and you stop it you get a deflation as well. You get the opposite end of euphoria, something more like despondence and gloominess.”

Like any other addiction, excessive exercise is characterized by tolerance and withdrawal, Hoffman said. Tolerance is measured by the amount of the behavior that an ordinary person would do. Withdrawal is measured by the psychological effects experienced by a person who is removed from his typical level of use.
He said there is a difference between addiction and dependence and this is where tolerance and withdrawal should be factored in.

“When you run, chemicals are released that make you feel euphoric and good,” he said. “As long as it isn't damaging your other relationships, a running dependence can not only be tolerated, but also be maintained.”

Dr. Krystian Bigosinski, a primary care sports medicine physician at Midwest Orthopedics at Rush University, said he observes an increase in exercise addiction-related injuries leading up to marathons.

“For the marathon, exercise addicts start training more. They train through the pain until they absolutely can’t run anymore,” he said.

Though permanent disabling injuries are rare, exercise addiction comes with risks, such as stress fractures and muscle strain, Bigosinski said.

Excessive exercise can also cause problems beyond the physical, such as relationship instability, depression, anxiety and a sense of hopelessness, said Michele Kerulis, adjunct professor of sport and exercise psychology at the Chicago School of Professional Psychology.

Bigosinski said that patients who fixate on the minutia of their exercise, down to the minute or the hundreds of feet, are the patients most likely to have an addiction.

“Some people are too tuned into the volume of exercise they are getting,” he said “And they cannot reduce their exercise for a day or two to avoid more injuries.”

Done correctly, however, running can be a healthy source of a natural high. Hoffman recommended that runners consult with a physician throughout their training, ensure that they get enough rest, and be mindful that running doesn’t negatively affect their health and relationships.

“The fact that somebody is young perhaps gives them a false sense of assurance that everything is OK.  But that may not be the wisest course,” he said. “If things are done incorrectly now, it may be responsible for problems of significance 10 or 20 years later.”

Kerulis agreed, saying that balance is key to healthy running.

“Runners who are mentally and physically healthy tend to create a running schedule that fits into their lives without causing distress to normal functioning—work, school, relationships,” she said.