PURPOSE To obtain estimates of time to recruit the study sample, retention, facility-based class attendance and home practice for a study of yoga in breast cancer survivors, and its efficacy on fatigue, quality of life (QOL), and weight change. METHODS Sixty-three post-treatment stage 0–III borderline overweight and obese (body mass index ≥ 24 kg/m2) breast cancer survivors were randomly assigned to a 6-month, facility- and home-based viniyoga intervention (n = 32) or a waitlist control group (n = 31). The yoga goal was 5 practices per week. Primary outcome measures were changes in self-reported QOL, fatigue, and weight from baseline to 6 months. Secondary outcomes included changes in waist and hip circumference. RESULTS It took 12 months to complete recruitment. Participants attended a mean of 19.6 classes and practiced at home a mean of 55.8 times during the 6-month period. At follow-up, 90% of participants completed questionnaires and 87% completed anthropometric measurements. QOL and fatigue improved to a greater extent among women in the yoga group relative to women in the control group, although no differences were statistically significant. Waist circumference decreased 3.1 cm (95% CI: −5.7, −0.4) more among women in the yoga compared with the control group, with no differences in weight change. CONCLUSIONS This study provides important information regarding recruitment, retention, and practice levels achieved during a 6-month, intensive yoga intervention in overweight and obese breast cancer survivors. Yoga may help decrease waist circumference and improve quality of life; future studies are needed to confirm these results.

IntroductionStress in numerous contexts may affect the risk for obesity through biobehavioral processes. Acute stress has been associated with diet and physical activity in some studies; the relationship between everyday stress and such behavior is not clear. The objective of this study was to examine associations between perceived stress, dietary behavior, physical activity, eating awareness, self-efficacy, and body mass index (BMI) among healthy working adults. Secondary objectives were to explore whether eating awareness modified the relationship between perceived stress and dietary behavior and perceived stress and BMI.MethodsPromoting Activity and Changes in Eating (PACE) was a group-randomized worksite intervention to prevent weight gain in the Seattle metropolitan area from 2005 through 2007. A subset of 621 participants at 33 worksites provided complete information on perceived stress at baseline. Linear mixed models evaluated cross-sectional associations.ResultsThe mean (standard deviation [SD]) Perceived Stress Scale-10 score among all participants was 12.7 (6.4), and the mean (SD) BMI was 29.2 kg/m2 (6.3 kg/m2). Higher levels of perceived stress were associated with lower levels of eating awareness, physical activity, and walking. Among participants who had low levels of eating awareness, higher levels of perceived stress were associated with fewer servings of fruit and vegetables and greater consumption of fast food meals. ConclusionDietary and physical activity behaviors of workers may be associated with average levels of perceived stress. Longitudinal studies are needed, however, to support inclusion of stress management or mindfulness techniques in workplace obesity prevention efforts.

Although yoga is an effective treatment for chronic low back pain, little is known about the mechanisms responsible for its benefits. In a trial comparing yoga to intensive stretching and self-care, we explored whether physical (hours of back exercise/week), cognitive (fear avoidance, body awareness, and self-efficacy), affective (psychological distress, perceived stress, positive states of mind, and sleep), and physiological factors (cortisol, DHEA) mediated the effects of yoga or stretching on back-related dysfunction (Roland-Morris Disability Scale (RDQ)). For yoga, 36% of the effect on 12-week RDQ was mediated by increased self-efficacy, 18% by sleep disturbance, 9% by hours of back exercise, and 61% by the best combination of all possible mediators (6 mediators). For stretching, 23% of the effect was mediated by increased self-efficacy, 14% by days of back exercise, and 50% by the best combination of all possible mediators (7 mediators). In open-ended questions, ≥20% of participants noted the following treatment benefits: learning new exercises (both groups), relaxation, increased awareness, and the benefits of breathing (yoga), benefits of regular practice (stretching). Although both self-efficacy and hours of back exercise were the strongest mediators for each intervention, compared to self-care, qualitative data suggest that they may exert their benefits through partially distinct mechanisms.