Physical activity (PA) may be useful in addressing the physiological and psychological causes of relapse to smoking (Bock, et al., 1999, Ussher, et al., 2001). A systematic review of 12 studies comparing a bout of exercise with a passive condition reported a positive effect for reducing cigarette cravings, negative affect, withdrawal symptoms, and smoking behavior (Taylor, et al., 2007). Two additional studies concluded the effect of PA was irrespective of the intensity level (moderate vs. vigorous). Further, the mechanism by which PA reduces desire to smoke and nicotine withdrawal symptoms is distinct from simple cognitive distraction (Daniel, et al., 2006).

Though most people who quit smoking will gain less than 10 pounds (Williamson, et al., 1991), weight gain concerns are predictive of smoking initiation, reluctance to quit smoking, and smoking relapse (Gritz, et al., 1991; Klesges, et al., 1989; Perkins, et al., 1995). For managing weight gain associated with quitting smoking, clinical practice guidelines recommend PA, rather than dieting (Fiore, et al., 2000). In general practice, PA is an effective strategy for weight gain prevention (USDHHS, 1996).

Adults who smoke tend to be less physically active than nonsmokers (Kaczynski, et al., 2008). Unger (1996) observed that adults preparing to quit smoking exercised more than smokers in the earlier stages of change. Further, a significant positive association has been found between one’s self-efficacy for quitting smoking and self-efficacy for maintaining PA (Boudreaux, et al., 2003).

The evidence for PA as a strategy for supporting smoking cessation, however, is not strong. A Cochrane review of 11 randomized controlled trials examining PA as a smoking cessation strategy concluded that while exercise promotion did not appear to harm smoking cessation efforts, there was limited evidence that it helped (Ussher, 2005). Only one of the 11 trials found evidence for PA aiding smoking cessation at long term follow-up (Marcus, et al., 1999). The program was highly structured, supervised, and promoted PA of vigorous intensity. A follow up study that promoted engagement in moderate PA and used more of a home-based approach failed to find an effect for long-term cessation relative to a standard cognitive behavioral cessation program (Marcus, et al., 2005). In the Cochrane review, only two studies reported changes in PA, limiting our understanding of the feasibility of smokers making changes in their tobacco use and PA patterns concurrently (Ussher, 2005). A follow up study reported no long-term effect of a PA intervention on tobacco abstinence, but also reported no difference in PA levels between the intervention and control conditions (Ussher, et al., 2007).

When quitting smoking, the timing of the PA program and the intensity of PA promoted (vigorous vs. moderate) may be important. Moderate or “lifestyle” exercise programs may offer greater efficacy and practicality for dissemination (Dunn, et al., 1998, King, 1998), greater participant adherence (King, et al., 1995), and greater appeal to sedentary smokers (Ussher, et al., 2001). The current study examined: (1) the impact of an extended relapse prevention program on increasing moderate to vigorous PA (MVPA) in adults enrolled in a tobacco cessation treatment trial; (2) whether changes in MVPA were associated with sustained abstinence from smoking; and (3) mechanisms by which MVPA may support sustained abstinence from smoking. Hypothesized mechanisms included enhanced psychological states, reduced withdrawal symptoms, improved health functioning, reduced weight gain, and greater motivation and self-efficacy to stay tobacco-free. Baseline correlates of PA also were examined with sample demographic and tobacco use characteristics.

Change in MVPA significantly predicted sustained abstinence from smoking at week 24. Increases in PA were associated with a greater likelihood of sustained abstinence from smoking, while relapse to smoking was associated with decline in activity. The findings are consistent with a recent prospective 7-year observational study with 750 Japanese men in which increased habitual exercise was associated with smoking cessation, while smoking relapse was associated with reduced habitual exercise (Nagaya, et al., 2007).

Examining MVPA changes by abstinence status and condition, MVPA increased among PA intervention participants who sustained abstinence, remained unchanged among intervention participants who relapsed or control participants with sustained abstinence, and declined among control participants who relapsed. The PA intervention appeared to increase PA among participants who quit smoking and mitigate declines in PA among those who relapsed.

Among participants with sustained abstinence at week 24, increased MVPA was associated with decreased perceived difficulty with remaining smoke-free and an increased state of vigor. Engagement in PA may have reinforced participants’ commitment to a healthy lifestyle, which did not include smoking. In the literature, a significant cross-sectional association has been found between self-efficacy for smoking cessation and exercise adoption (King, et al., 1996). Individuals working on increasing their PA seem confident about decreasing their smoking and vice versa. Previous studies also have reported higher ratings of vigor among adults who are more physically active (LeUnes, 2000). Engagement in PA may help to offset the fatigue and sleep problems characteristic of nicotine withdrawal (American Psychiatric Association [APA], 1994).

The lack of significant correlations between changes in MVPA and other nicotine withdrawal symptoms and BMI may reflect the timing of the intervention and assessment schedule. The PA sessions came 13 weeks after the scheduled quit date, likely too late to impact most nicotine withdrawal symptoms, which typically last only 2 to 4 weeks (APA, 1994). For weight gain prevention, the week 24 assessment (only 4 weeks after the second PA session) may have been too soon to detect an effect.

Strengths of the current study include a large sample size and use of a validated PA self-report measure. Though used largely as a surveillance tool in the literature, the IPAQ demonstrated sensitivity to detecting changes overtime associated with an intervention. A limitation of the IPAQ, however, was the high degree of skew making use of the raw data for examining baseline PA levels misleading. Despite this limitation, brief measures, such as the IPAQ, are particularly useful in studies targeting and assessing multiple health behaviors given concerns with respondent burden. In the current sample, self-reported MVPA correlated significantly with objective pedometer counts.

The study is limited in that it focused on short-term effects of a PA intervention on smoking abstinence. Despite a randomized design, participants in the relapse prevention group reported lower levels of MVPA at baseline relative to control participants. The difference was stable with the repeated baseline assessment design, apparent at both the baseline and week 12 assessments. The low compliance with pedometer monitoring also limits the study findings. Only 15% of participants in the PA intervention provided 6 weeks of pedometer monitoring. The PA intervention was part of an extended relapse prevention intervention with multiple objectives: nicotine withdrawal, mood management, social support, ongoing motivation, and weight gain prevention through PA promotion. Given the multiple foci, participants may have opted to focus on the issues of greatest concern or interest to them. A study of smokers with severe mental illness reported that 63% were interested in assistance to increase their PA levels while quitting smoking (Faulkner, et al., 2007). Given the high rates of tobacco use and inactivity among persons with mental illness, this group presents a unique population worthy of study with perhaps even greater potential synergism for PA’s effects on enhancing mood and reducing nicotine withdrawal symptoms.

The leading causes of morbidity and mortality in the US -- heart disease, stroke, diabetes, and cancer -- are influenced by tobacco use and sedentary lifestyles. Risk behaviors have been shown to cluster and tobacco users, in particular, tend to have poor behavioral profiles, with about 92% of smokers having at least one additional risk behavior (Fine, et al., 2004, Klesges, et al., 1990, Pronk, et al., 2004). In the 2001 National Health Interview Study, 70% of current smokers were classified as physically inactive (Fine, et al., 2004). Interventions that address multiple behaviors, such as tobacco use and PA, have the potential to offer greater health benefits, more adequately address participants’ behavioral profiles, maximize health promotion opportunities, and reduce health care costs.