The efficacy of Bikram yoga in stressed and sedentary adults

Abstract

Background: Cardiovascular disease (CVD) is the leading cause of death worldwide. It has been well documented that physical inactivity (sedentary lifestyle) and chronic psychosocial stress both contribute to the development of key CVD risk factors. CVD related morbidity and mortality could likely be reduced if a larger proportion of the public were to adopt healthier lifestyle behaviours, including quality physical activity and effective stress management techniques. Research Program: This research program was undertaken from March 2013 to May 2017. The research culminated in a randomised controlled trial (RCT) conducted across two Bikram yoga studios in the Australian Capital Territory (Canberra, ACT). Aims: Overall, this research program aimed to investigate the effect of Bikram yoga on the physiological and psychological health outcomes in stressed and sedentary adults. Specifically, the aims were: (i) to critically review the existing literature on Bikram yoga and provide recommendations for future trials; (ii) to investigate the effect of a 16-week Bikram yoga intervention on the high-frequency (HF) power component of heart rate variability (HRV), secondary measures of HRV and associated CVD risk factors; (iii) to investigate the effect of a 16-week Bikram yoga intervention on measures of psychological health status; and (iv) to investigate predictors of and barriers to adherence to the 16-week Bikram yoga intervention. Conclusions: Chapter eight presents the overall thesis summary, conclusions and future research directions. In summary, this thesis has made a significant contribution to furthering the current understanding of Bikram yoga intervention in sedentary and stressed adults through a narrative review of existing research, and by conducting a rigorous RCT. The narrative review in chapter three revealed potential benefits of Bikram yoga on fitness outcomes, psychological outcomes, and some physiological outcomes in certain populations. The current body of literature exhibits a general weakness in methodology. Evidence from the 16-week RCT presented in chapters five and six reported little to no effect on HRV and CVD risk factors, and positive adaptation of several psychological health measures in sedentary and stressed adults, compared to no-treatment. A dose-response effect appears to exist, and as shown in chapter seven, adherence was influenced by several baseline characteristics, and inhibited by time constraints, enjoyment of Bikram yoga, and adverse events. Continued research via RCT design is required to investigate the effect of Bikram yoga in larger samples and higher risk populations, with consideration of potential barriers to adherence prior to intervention.

Date of Award	2017
Original language	English