Effects of exercise on cravings to smoke: the role of exercise intensity and cortisol.

Research consistently demonstrates that a bout of moderate exercise alleviates cravings to smoke among abstaining smokers. The aims of this study were to examine whether doses of exercise (moderate or vigorous) reduced cravings differently, and whether reductions in cravings were associated with changes in cortisol concentration. Using a within-participant, crossover design, 18 participants conducted three 15-min treatment sessions on separate days: passive, walking (45-50% heart rate reserve), and running (80-85% heart rate reserve) conditions. Participants rated cravings at baseline, mid-treatment, and 0, 10, 20, and 30 min after each treatment. Salivary cortisol samples were collected at baseline, immediately after, and 30 min after each condition. Significant group x time interactions were identified, demonstrating significant reductions in craving items after the walking and running conditions compared with the passive control. No significant differences in craving reductions were found between walking and running conditions. Post hoc comparisons found that running condition cravings to smoke scores were reduced for a longer duration post-treatment than post-walking condition scores. The decline in cortisol concentration was attenuated in the running group only. Vigorous exercise has a similar effect to moderate exercise in terms of the magnitude of craving reduction. However, performing bouts of moderate-intensity exercise may be a better recommendation for reducing cravings.