Abstract
PURPOSE: This study investigated the effect of a 16-week Bikram yoga intervention on the high frequency (HF) power component of heart rate variability (HRV) and associated physiological and psychological outcomes in stressed and sedentary adults.
METHODS: Eligible adults were randomized to an experimental group (n=29) or a no-treatment control group (n=34) after baseline testing. Experimental group participants were instructed to attend three to five Bikram yoga classes per week at local studios. All outcomes were collected at baseline (week 0) and completion (week 17), with psychological outcomes also collected at midpoint (week 8). Secondary physiological outcomes included additional HRV measures, blood pressure, augmentation index, body composition (via DEXA), waist circumference, fasting blood glucose, cholesterol, and C-reactive protein. Secondary psychological outcomes included the Perceived Stress Scale, the General- and Exercise Self-Efficacy Scales and health-related quality of life (HRQoL) measures (via Short-Form-36).
RESULTS: Sixty-three adults (37.2±10.8 years, 79% women) were enrolled in the study and included in the intention-to-treat analysis. The experimental group attended 27±18 classes. The HF component of HRV did not significantly change between groups over time, nor did any secondary physiological endpoints. However, higher attendance to the intervention was associated with significant reductions in diastolic blood pressure (p=0.039), body fat percentage (p=0.001), fat mass (p=0.003) and body mass index (p=0.05). Further, the experimental group significantly improved several psychological endpoints versus the control group including perceived stress (p = 0.003), general self-efficacy (p=0.034), exercise self-efficacy (p=0.003), and HRQoL ‘Vitality’ (p=0.019) and ‘General Health’ (p=0.034).
CONCLUSIONS: A 16-week Bikram yoga program did not increase the HF power component of HRV or any physiological outcomes evaluated. Low adherence possibly contributed to these null effects. However, participants in the experimental group significantly improved perceived stress, and measures of self-efficacy and HRQoL. Future studies are required to address barriers to adherence and elucidate the dose-response effects of Bikram yoga practice.
METHODS: Eligible adults were randomized to an experimental group (n=29) or a no-treatment control group (n=34) after baseline testing. Experimental group participants were instructed to attend three to five Bikram yoga classes per week at local studios. All outcomes were collected at baseline (week 0) and completion (week 17), with psychological outcomes also collected at midpoint (week 8). Secondary physiological outcomes included additional HRV measures, blood pressure, augmentation index, body composition (via DEXA), waist circumference, fasting blood glucose, cholesterol, and C-reactive protein. Secondary psychological outcomes included the Perceived Stress Scale, the General- and Exercise Self-Efficacy Scales and health-related quality of life (HRQoL) measures (via Short-Form-36).
RESULTS: Sixty-three adults (37.2±10.8 years, 79% women) were enrolled in the study and included in the intention-to-treat analysis. The experimental group attended 27±18 classes. The HF component of HRV did not significantly change between groups over time, nor did any secondary physiological endpoints. However, higher attendance to the intervention was associated with significant reductions in diastolic blood pressure (p=0.039), body fat percentage (p=0.001), fat mass (p=0.003) and body mass index (p=0.05). Further, the experimental group significantly improved several psychological endpoints versus the control group including perceived stress (p = 0.003), general self-efficacy (p=0.034), exercise self-efficacy (p=0.003), and HRQoL ‘Vitality’ (p=0.019) and ‘General Health’ (p=0.034).
CONCLUSIONS: A 16-week Bikram yoga program did not increase the HF power component of HRV or any physiological outcomes evaluated. Low adherence possibly contributed to these null effects. However, participants in the experimental group significantly improved perceived stress, and measures of self-efficacy and HRQoL. Future studies are required to address barriers to adherence and elucidate the dose-response effects of Bikram yoga practice.
Original language | English |
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Pages (from-to) | 794-794 |
Number of pages | 1 |
Journal | Medicine and Science in Sports and Exercise |
Volume | 49 |
Issue number | 5 |
DOIs | |
Publication status | Published - May 2017 |