First Brain Imaging Study to Show Benefits of Exercise on Smoking Cessation

These new findings show how exercise alters the way the brain processes information among smokers, thereby reducing their cravings for nicotine.

For the first time, researchers utilized functional magnetic resonance imaging (fMRI) to investigate how the brain processes images of cigarettes after exercise. The study, slated for publication in the journal Psychopharmacology, adds credence to a growing body of evidence that exercise can help manage addiction to nicotine and other substances. It supports earlier studies, which have shown that just one short burst of moderate exercise can considerably reduce smokers' nicotine cravings.

Investigators from the University of Exeter (UK) reported on their study involving 10 regular smokers were asked to cycle at a moderate pace for 10 minutes, after 15 hours of abstinence from nicotine. They then underwent fMRI scanning while they viewed a series of 60 images. Some visuals featured cigarettes and would normally induce cravings in a smoker. On a second occasion, the same group was given an fMRI scan and shown the same series of images without having undertaken exercise. They were also asked to report on their cravings for nicotine during both phases of the study. The brain images captured by the fMRI showed a difference between the two conditions.

After no exercise the smokers demonstrated increased activity in response to the images in areas of the brain associated with reward-processing and visual attention. After exercise, the same regions of activation were not observed, which reflected a sort of ‘default mode' in the brain. The smokers also reported lower cravings for cigarettes after exercise compared with when they had been inactive.

The researchers do not know precisely what caused the difference in brain activity following exercise. One suggestion is that completing exercise raises mood (perhaps through increases in dopamine), which reduces the salience or importance of wanting a cigarette. Another possibility is that exercise causes a shift in blood flow to areas of the brain less involved in anticipation of reward and pleasure generated by smoking images.

Earlier research by investigators from the University of Exeter has suggested that exercise can reduce nicotine cravings. Results from a series of studies demonstrated that smokers report reduced cigarette cravings after exercising. This study showed that exercise could reduce cravings when smokers are faced with images that have been previously shown to cause lapses in smokers trying to quit. This is the first time that anyone has investigated brain activity during this process.

Kate Janse Van Rensburg, a Ph.D. student at the University of Exeter, and lead author on the study, remarked, "Our findings add to a growing body of evidence suggesting that exercise can help people give up smoking. This strengthens the argument that moderate exercise could be a viable alternative to many of the pharmaceutical products, such as nicotine patches, for people who want to give up smoking. A 10- or 15-minute walk, jog, or cycle when times get tough could help a smoker kick the habit. There are of course many other benefits from a more active lifestyle including better fitness, weight loss, and improved mood.”

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