London, Feb 11 (IANS) Physical exercise triggers brain activity that may help reduce craving for cigarettes. For the first time, researchers used functional Magnetic Resonance Imaging (fMRI) to investigate how the brain processes images of cigarettes after exercise.

The study backs up previous studies, which have shown that just one short burst of moderate exercise can significantly reduce smokers’ nicotine cravings.

Kate Janse Van Rensburg, doctoral student at the University of Exeter, who co-authored the paper, said: “Our findings add to a growing body of evidence suggesting that exercise can help people give up smoking.

Ten regular smokers were asked to cycle at a moderate pace for 10 minutes, after 15 hours of abstinence from nicotine. They were then given an fMRI scan 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 show a difference between the two conditions. After no exercise the smokers showed heightened activity in response to the images in areas of the brain associated with reward-processing and visual attention.

After exercise the same areas of activation were not observed, which reflected a kind of ‘default mode’ in the brain. The smokers also reported lower cravings for cigarettes after exercise compared with when they had been inactive, said an Exeter release.

The researchers do not know exactly what caused the difference in brain activity following exercise. One suggestion is that completing exercise raises mood (possibly through increases in dopamine) which reduces the importance of wanting a cigarette.

These results were published in Psychopharmacology.