Impact of aerobic exercise intensity on craving and reactivity to smoking cues.

Aerobic exercise can acutely reduce cigarette cravings during periods of nicotine deprivation. The primary aim of this study was to assess the differential effects of light and vigorous intensity aerobic exercise on cigarette cravings, subjective and physiological reactivity to smoking cues, and affect after overnight nicotine deprivation. A secondary aim was to examine cortisol change as a mediator of the effects of exercise on smoking motivation. 162 (55 female, 107 male) overnight nicotine-deprived smokers were randomized to one of three exercise conditions: light intensity, vigorous intensity, or a passive control condition. After each condition, participants engaged in a standardized cue reactivity assessment. Self-reported urges to smoke, affect, and salivary cortisol were assessed at baseline (i.e., before each condition), immediately after each condition, and after the cue reactivity assessment. Light and vigorous exercise significantly decreased urges to smoke and increased positive affect, relative to the control condition. In addition, those in the vigorous exercise condition demonstrated suppressed appetitive reactivity to smoking cues, as indexed by the startle eyeblink reflex. Although exercise intensity was associated with expected changes in cortisol concentration, these effects were not related to changes in craving or cue reactivity. Both light and vigorous exercise can reduce general cravings to smoke, whereas vigorous exercise appears especially well-suited for reducing appetitive reactions to cues that may precede smoking. Results did not support exercise-induced cortisol release as a mechanism for these effects.

The acute effects of physical activity on cigarette cravings: systematic review and meta-analysis with individual participant data.

AIMS: To conduct an updated systematic review and the first meta-analysis of experimental trials investigating the acute effects of short bouts of physical activity (PA) on strength of desire (SoD) and desire to smoke (DtS) using individual participant data (IPD). METHODS: A systematic review of literature and IPD meta-analyses included trials assessing the acute effects of shorts bouts of PA on SoD and DtS among temporarily abstaining smokers not using pharmaceutical aids for smoking cessation. Authors of eligible studies were contacted and raw IPD were obtained. Two-stage and one-stage IPD random-effects meta-analyses were conducted. Participants engaging in PA were compared against control participants, using post-intervention SoD and DtS with baseline adjustments. RESULTS: A two-stage IPD meta-analysis assessing effects of PA on SoD yielded an average standardized mean difference (SMD) between PA and control conditions (across 15 primary studies) of -1.91 [95% confidence interval (CI): -2.59 to -1.22]. A two-stage IPD meta-analysis assessing effects of PA on DtS yielded an average SMD between PA and control conditions (across 17 primary studies) of -2.03 (95% CI: -2.60 to -1.46). Additional meta-analyses, including those using a one-stage model, those including only parallel arm studies and meta-analyses comparing only moderate exercise against a control condition, showed significant craving reduction following PA. Despite a high degree of between-study heterogeneity, effects sizes of all primary studies were in the same direction, with PA showing a greater reduction in cravings compared with controls. CONCLUSIONS: There is strong evidence that physical activity acutely reduces cigarette craving.

Transient compensatory smoking in response to placebo cigarettes.

RATIONALE: To address the public health problems caused by smoking, researchers have suggested a gradual reduction in the nicotine content of cigarettes. There remain concerns, however, about the potential for smokers to compensate for reductions in nicotine content by altering their smoking behavior. Such compensatory behaviors may negate any potential cessation and/or harm reduction benefits. OBJECTIVE: The purpose of this study was to quantify smoking behavior (e.g., puff number, volume, duration, interpuff interval, and peak flow) in response to cigarettes, varying only in nicotine content, administered repeatedly. METHODS: Sixty-seven dependent smokers participated in this two-session, within-subject study. Moderate nicotine content and placebo cigarettes (Quest© brand) were administered in a double-blind and counterbalanced manner. Each session required 12 h of tobacco abstinence and included four ad lib smoking bouts of the condition-assigned cigarette with 40 minutes separating each bout. RESULTS: Placebo cigarettes produced increases in total puff volume and duration and decreases in total interpuff interval relative to cigarettes with moderate nicotine content. Differences in total puff volume and duration generally dissipated across smoking bouts, with differences in total puff volume nonexistent by the third and fourth bouts. CONCLUSIONS: Placebo cigarettes produce compensatory smoking during initial exposures; however, these effects appear to be short lived. These findings are consistent with the previous work where smoking compensation has been observed in response to a single cigarette, but not over several days of smoking.

The effects of exercise on cigarette cravings and brain activation in response to smoking-related images.

RATIONALE: Smokers show heightened activation toward smoking-related stimuli and experience increased cravings which can precipitate smoking cessation relapse. Exercise can be effective for modulating cigarette cravings and attenuating reactivity to smoking cues, but the mechanism by which these effects occur remains uncertain. OBJECTIVE: The objective of the study was to assess the effect of exercise on regional brain activation in response to smoking-related images during temporary nicotine abstinence. METHODS: In a randomised crossover design, overnight abstinent smokers (n = 20) underwent an exercise (10-min moderate-intensity stationary cycling) and passive control (seating for the same duration) treatment, following 15 h of nicotine abstinence. After each treatment, participants underwent functional magnetic resonance imaging (fMRI) brain scanning while viewing a random series of blocked smoking or neutral images. Self-reported cravings were assessed at baseline, mid-, and post-treatments. RESULTS: There was a significant interaction effect (treatment × time) for desire to smoke, F (2,32) = 12.5, p < 0.001, with significantly lower scores following the exercise at all time points compared with the control treatment. After both exercise and rest, significant areas of activation were found in areas of the limbic lobe and in areas associated with visual attention in response to smoking-related stimuli. Smokers showed increased activation to smoking images in areas associated with primary and secondary visual processing following rest, but not following a session of exercise. CONCLUSION: The study shows differing activation towards smoking images following exercise compared to a control treatment and may point to a neuro-cognitive process following exercise that mediates effects on cigarette cravings.

Acute effects of aerobic exercise and Hatha yoga on craving to smoke.

INTRODUCTION: Recent studies have examined the effects of physical activity on craving to smoke and smoking withdrawal. The current study was designed to compare and contrast the effects of 2 different forms of physical activity on general and cue-elicited craving to smoke. METHODS: Following 1-hr nicotine abstinence, 76 daily smokers were randomly assigned to engage in a 30-min bout of cardiovascular exercise (CE; brisk walk on a treadmill), Hatha yoga (HY), or a nonactivity control condition. Participants completed measures of craving and mood, and a smoking cue reactivity assessment, before, immediately following, and approximately 20 min after the physical activity or control conditions. RESULTS: Compared with the control condition, participants in each of the physical activity groups reported a decrease in craving to smoke, an increase in positive affect, and a decrease in negative affect. In addition, craving in response to smoking cues was specifically reduced among those who engaged in CE, whereas those who engaged in HY reported a general decrease in cravings. CONCLUSIONS: This study provides further support for the use of exercise bouts for attenuating cigarette cravings during temporary nicotine abstinence. Results also suggest that CE can attenuate cravings in response to smoking cues. There are several areas for further research that may improve integration of exercise within smoking cessation treatment.

Acute exercise modulates cigarette cravings and brain activation in response to smoking-related images: an fMRI study.

RATIONALE: Substances of misuse (such as nicotine) are associated with increases in activation within the mesocorticolimbic brain system, a system thought to mediate the rewarding effects of drugs of abuse. Pharmacological treatments have been designed to reduce cigarette cravings during temporary abstinence. Exercise has been found to be an effective tool for controlling cigarette cravings. OBJECTIVE: The objective of this study is to assess the effect of exercise on regional brain activation in response to smoking-related images during temporary nicotine abstinence. METHOD: In a randomized crossover design, regular smokers (n = 10) undertook an exercise (10 min moderate-intensity stationary cycling) and control (passive seating for same duration) session, following 15 h of nicotine abstinence. Following treatments, participants entered a functional Magnetic Resonance Imaging (fMRI) scanner. Subjects viewed a random series of smoking and neutral images for 3 s, with an average inter-stimulus-interval (ISI) of 10 s. Self-reported cravings were assessed at baseline, mid-, and post-treatments. RESULTS: A significant interaction effect (time by group) was found, with self-reported cravings lower during and following exercise. During control scanning, significant activation was recorded in areas associated with reward (caudate nucleus), motivation (orbitofrontal cortex) and visuo-spatial attention (parietal lobe, parahippocampal, and fusiform gyrus). Post-exercise scanning showed hypo-activation in these areas with a concomitant shift of activation towards areas identified in the 'brain default mode' (Broadmanns Area 10). CONCLUSION: The study confirms previous evidence that a single session of exercise can reduce cigarette cravings, and for the first time provides evidence of a shift in regional activation in response to smoking cues.

The effects of acute exercise on cognitive functioning and cigarette cravings during temporary abstinence from smoking.

BACKGROUND: Abstinence from smoking is associated with increased cravings, risk of accidents and self-reported poor concentration. A single exercise session can reduce cravings and self-reported poor concentration and can enhance cognitive performance among non-smokers. OBJECTIVE: To assess whether acute exercise impacts on the cognitive performance and cravings of abstaining smokers. METHODS: In a counterbalanced cross-over design, participants (n = 23) did a 15 min passive or exercise condition, following cigarette abstinence. Cognitive functioning was measured by a computerised version of the Stroop colour-word interference task. Cravings were measured using the 10-item, 2-factor QSU-Brief and a single item for 'desire to smoke'. Measures were recorded at baseline, immediately post, 5, 10 and 15-min post treatment. RESULTS: A 2-way ANOVA showed no significant condition x time interaction for cognitive functioning. Significant interaction effects were found for desire to smoke, QSU Factor 1 (desire-behave) and 2 (desire-affect). Exercise reduced cravings for up to 15 min post treatment. DISCUSSION: Findings support previous research that acute exercise reduces cravings to smoke. Future research should determine if exercise can enhance other objective aspects of cognitive performance, and repeat the present study with a more homogeneous sample, in terms of Stroop performance. CONCLUSION: This is the first study to show that exercise can reduce both factors of the QSU-Brief, but effects on cognitive functioning were not observed.