Rationale, design, and baseline data for Commit to Quit: an exercise efficacy trial for smoking cessation among women

BACKGROUND: The Commit to Quit trial was designed to address the methodological problems of prior studies that have examined the contribution of exercise to smoking cessation. METHODS: This paper provides an overview of the study design and describes the sample of women who participated in this trial (N = 281). Interrelationships among eating, exercise, and smoking behavior are examined. RESULTS: Subjects randomized into the study compared with the sample of women who completed the initial assessment but were not randomized were more likely to be white, to have at least a high school education, and to smoke fewer cigarettes per day. Overall, the most frequent ineligibility criteria were health-related issues and scheduling conflicts. On average, participants in this study smoked more cigarettes per day than national samples of women smokers. Significant interrelationships include the positive association of motivational readiness for quitting smoking and enhanced levels of dietary restraint and the positive association of motivational readiness for exercise adoption and high levels of weight concern. CONCLUSIONS: This study represents the first adequately powered randomized controlled clinical trial comparing the relative efficacy of a cognitive-behavioral smoking cessation treatment plus vigorous exercise with the same treatment plus contact control.