Participants will complete carbon monoxide (CO) analysis of breath sample (≥8ppm cutoff; Jarvis et al., 1987) to determine smoking status during ad-libitum phases and to assess smoking quit status during the quit period.

Participants will complete the full timeline follow back calendar (TLFB; past-week) to assess daily point-prevalence of cigarettes both as a screening tool (reflecting ≥ 10 cigarettes/day on average for the past year; and throughout the study period. point prevalence during quit period will be examined between groups and verified with biochemical measurement of lung carbon monoxide (CO)

The FFMQ (Baer et al., 2006) is a 39-item self-report measure of mindfulness components: observing, describing, acting with awareness, nonjudging of inner experience, and nonreactivity to inner experience. This will be given across intervention to assess changes in response to the mindfulness-based practice of yoga (i.e., with changes compared between groups).

BIS-15 (Spinella, 2007) is a 15-item self-report measure of 3 non-overlapping impulsivity components: non-planning, motor impulsivity, and attention impulsivity. As one of the most commonly used measures of impulsivity, it has demonstrated validity and reliability in neuropsychiatric and healthy populations. The 15-item short form of the BIS has shown to retain its 3-factor structure when subject to factor analysis and maintained good reliability and validity (Spinella 2007). screening tool (coupled with the ASI) to select individuals scoring above the community norm for impulsivity (Mean score ≥ 32.6 out of 54), as this smoking population may be especially at risk for reactivity to withdrawal symptoms/withdrawal related relapse.

BART is a laboratory-based behavioral measure of risk taking, evidencing sound experimental properties. It has been shown to predict risk-related constructs (e.g., impulsivity, sensation seeking) as well as self-reported real-world risk behaviors in adults and adolescents (Lejuez et al., 2002). Riskiness on the BART has been correlated with occurrence of addictive, health, and safety risk behaviors, indicating that the BART may be a useful clinical assessment tool. Importantly, as smokers have demonstrated greater total riskiness and sensation seeking on the BART, we will administer the task at pre-and-post intervention as a secondary predictor of smoking outcomes in our trial, possibly indicative of greater difficulty quitting related to impulsivity (which may also be aided with yoga, and thus, differences in behavior will be compared between groups).

The Delay Discounting choice task is a valid and reliable computer adaptive procedure developed for the purpose of studying choice behavior and delayed reward (Richards et al., 1999). The program asks the participant to decide between a higher amount of money (e.g., $10) to be received after one of the different delay periods (e.g., 1 day, 1 week) or a smaller amount of money (e.g. $1) to be received immediately. Because scores on DDT appear to be related to smoking status and level of nicotine dependence (Sweitzer et al., 2008) this measure was included both as a secondary screening predictor of smoking cessation success, and to observe possible pre-to-post changes afforded by yoga. Changes in behavior on this task will compared between groups.

The DTS (Simons & Gaher, 2005), a 15-item self-report measure of physical and psychological distress tolerance, will assess changes in DT; it consists of a 5-point Likert scale with possible ratings ranging from strongly agree to strongly disagree. DTS has high internal consistency (alpha=.82). This will serve as a secondary measurement of distress tolerance, accompanying the ASI, and assessed through between-group changes.

The MASQ is a self-report measure derived from the tripartite model (Watson et al., 1995). It includes 62 items rated on a scale ranging from 1 (not at all) to 5 (extremely) focusing on how much an individual has experienced specific affect symptoms in the past week. Four subscales include: Anxious Arousal, Anhedonic Depression, General Distress: Anxious Symptoms, and General Distress: Depressive symptoms. We will use the MASQ to assess affective changes in response to 12-hour withdrawal. The MASQ has been employed in previous smoking cessation work (e.g., Zvolensky et al., 2009), and therefore, beyond being psychometrically sound, offers a higher degree of comparability across research. Ratings will be compared between-groups

The FTND (Heatherton, Kozlowski, Frecker, & Fagerstrom, 1991) has shown good internal consistency, a single dimension factor structure, and positive relationships with degree of nicotine intake. Dependence status will be assessed at baseline, mid, and post-treatment. This measure will serve to quantify nicotine dependence, which will be used as a covariate in the primary analyses.

The BDI (Beck, Mendelson, Mock, & Erbaugh, 1961) is a widely used 21-item, self-report inventory designed to measure severity of depressive symptoms. Individuals will only be eligible with scores of ≤30 on the BDI (scores ≥30 indicate severe depression). The BDI will also be administered throughout the protocol to assess changes in depressive symptoms possibly affected through yoga.