Exercise expectancy and credibility scores as a factor of

and withdrawal relief

Similar to the work of Daniel et al. (2007), participants were categorised as either high or low in EX-EXP and EX-CRED at week five. Interestingly, it was demonstrated that individuals who were categorised as high in EX- EXP and EX-CRED had a significantly greater reduction in craving following an acute 20 minute bout of moderate intensity exercise, compared to those who were categorised as low in these two variables. This finding contradicts the findings of Daniel et al. (2007), but is in accordance with the psychotherapy outcome research that underscores the influence of these two variables (Newman & Fisher, 2010; Smeets et al., 2008). However, no significant differences between high and low groups were found for either psychological withdrawal, or the withdrawal symptom of sedation, findings that concur with those reported by Daniel et al. (2007). In addition, in accordance with Daniel and colleagues (2007), regardless of EX-EXP and EX-CRED beliefs all participants experienced a reduction in craving and withdrawal following an acute bout of moderate intensity exercise. Taken together, these findings suggest that expectancy and credibility beliefs are not a major mechanism by which exercise reduces the debilitating effects of

nicotine abstinence amongst both temporarily and recently quit smokers, but they may play some role.

Overall, the findings relating to the magnitude of craving and withdrawal relief experienced following exercise, both contradict and corroborate those of Daniel et al. (2007). This disparity may best be explained by examining the differences between these two studies. In the first instance, the participants that took part in the Daniel et al. (2007) study were required only to engage in temporary abstinence (12-15 hours) whereas the women who took part in the present study signed up for a 14 week exercise aided quit smoking programme. Therefore, the women in this study were fully invested in a quit attempt at week five of the programme, when the difference in craving between groups was observed. In the psychotherapy literature, there is evidence to suggest that the more invested in treatment outcomes an individual is, the greater the influence of expectancy and credibility beliefs on therapeutic effects (Greenberg, Constantino, & Bruce, 2006). Recently, change in expectancy has been suggested as a mechanism by which cognitive behavioural therapy leads to symptom change in generalised anxiety disorder (Newman & Fisher, 2010). Within the present paradigm, women in the high EX-EXP and EX-CRED group demonstrated an increase in these variables from baseline to week five whereas those in the low EX-EXP and EX-CRED groups did not. Although this difference was not significant, it provides support for the notion that positive changes in expectancy and credibility beliefs, in relation to treatment, support improvement in symptoms.

The results of Daniel and colleagues (2007) were based on a manipulated EX-EXP. In contrast, participants EX-EXP in the present study developed throughout the five weeks they were taking part in the intervention. As such, naturally occurring exercise expectancy

scores in the high EX-EXP group (mean 8.8/9) were greater than those in the Daniel et al. (2007) manipulated high EX-EXP group (mean 7.5/10). Perhaps, to experience an added reduction in craving recently quit smokers had to believe, almost without a doubt, that exercise would reduce the cigarette cravings associated with nicotine abstinence. Daniel and colleagues (2007) based their findings on the manipulation of expectancy measured on a credibility scale. Although expectancy and credibility beliefs may share commonalities they are essentially different (Devilly & Borkovec, 2000). Smokers may think that a new treatment such as exercise is credible, but this may differ from what they really feel or expect will be the outcome of treatment. As such, the findings of Daniel et al. (2007) may not actually be based on participants’ expectancies and should be interpreted with caution. In the present study participants engaged in 20 minutes of moderate intensity exercise as opposed to 10 minutes. In the acute exercise and smoking literature 20 minutes of moderate intensity exercise has been shown to have a greater impact on craving and withdrawal symptoms in temporarily abstinent smokers compared to 10 minutes of the same intensity exercise (Taylor et al., 2007). Perhaps, duration of exercise and EX-EXP interact in a way that impacts the influence of this variable on craving outcomes following an acute bout of exercise.

All women in the present study were using NRT in conjunction with exercise to help them quit smoking. Smokers in the Daniel et al. (2007) study were only temporarily abstinent and as such were not on NRT. In this instance, it is difficult to explain how NRT use might have influenced the results. Previous NRT and expectancy research has demonstrated that smokers strongly believe NRT will effectively reduce cigarette cravings (Juliano & Brandon, 2004). Possibly, the simultaneous administration of exercise with NRT, a well established credible quit

smoking aid, guided participants to believe exercise to be a relevant and logical quit smoking aid also. That is, participants’ predictions regarding the beneficial effects of exercise were bolstered because they believed they could fall back on NRT. It was demonstrated that week five EX-CRED and NRT-CRED were highly related, which supports this notion, but it is refuted by the lack of correlation between EX-EXP and NRT-EXP at week five. This finding also underscores the difference between expectancy and credibility as constructs.

A number of demographic variables were different between the two studies. For instance, women in the present study were more likely to be: older, employed, smoking for longer, smoked more per day, and were more heavily addicted. There were also gender differences. Namely, the present study was a cohort of women only whereas Daniel et al. (2007) included both men and women. It is perhaps unlikely that any of these variables made any real contribution to the resultant differences however it is worth acknowledging them.

EX-EXP and EX-CRED do not invariably carry the burden of craving and withdrawal outcome following an acute bout of exercise. However, individuals who held strong EX-EXP and EX-CRED beliefs did experience an added reduction in cigarette craving following an acute bout of moderate intensity exercise. The question is whether or not this added reduction in craving is clinically relevant (Smeets et al., 2008). Cigarette cravings are one of the most often expressed difficulties related to quitting. The intensity of craving experienced by an abstinent smoker over the first few days of quitting is often predictive of their success (Ferguson, Shiffman, & Gwaltney, 2006). That being the case, every further reduction, no matter how small, may be of clinical relevance. Each year at least 70 percent of smokers see a physician (Fiore, Jaen, & Baker, 2008). Others come into contact with dentists, nurse practitioners, nurses, physical therapists, occupational therapists,

pharmacists, and counsellors (Fiore et al., 2008). Therefore, almost all clinicians are in a position to intervene with smokers and offer them tobacco treatment (Fiore et al., 2008). If clinicians were to advocate exercise as an adjunct cessation aid it may serve to bolster smokers EX- EXP and EX-CRED beliefs. The challenge with this rests not so much on the smoker as it does on the clinician.