Walk it off: Examining the effects of exercise on self-control and cravings in smokers


Smoking is the leading cause of preventable death (Canadian Cancer Society, 2016). Although millions of Canadians try to quit each year, 95% of their quit attempts fail within a year (CDCP, 2011). Quitting requires self-control (SC)—a limited mental resource that leaves one susceptible to task failure upon depletion (Muraven & Baumeister, 2000). SC depletion increases lapse behaviour in smokers and cravings in deprived smokers (Heckman, 2014). A single bout of moderate-intense exercise alleviates cravings in abstinent smokers (Roberts, 2012). Unfortunately, the mechanism by which exercise exerts its effect is not well understood. We hypothesize that exercise reduces cravings by replenishing depleted SC resources during cessation. Thirteen smokers (M age = 43.15; 8 female) were randomized into 15 minutes of moderate-intensity exercise or passive control (read a magazine) conditions. A handgrip task was used to measure SC four times (baseline, post 24-h quit, post thought suppression task, and post exercise manipulation). Cigarette cravings were also assessed at these time points. Results showed no SC depletion effect after 24-h abstinence. However, a SC depletion effect was found after the thought suppression task (p < .05). Cravings were elevated (p < .05) and remained high following abstinence and thought suppression and then were reduced only for those who exercised (p < .05). Although not significant (p > .05), SC depletion continued for those in control condition but remained stable for those in the exercise condition. Preliminary data do not support the tenet that abstinence-induced cravings are reduced by exercise through SC replenishment pathways.