Objective and subjective measures of exercise intensity during thermo-neutral and hot yoga.
Appl Physiol Nutr Metab. 2017 Nov 23;:
Authors: Boyd CN, Lannan SM, Zuhl MN, Mora-Rodriguez R, Nelson RK
While hot yoga has gained enormous popularity in recent years due in part to increased environmental challenge associated with exercise in the heat, it is not clear whether hot yoga is more vigorous than thermo-neutral yoga. Therefore, the aim of this study was to determine objective and subjective measures of exercise intensity during constant intensity yoga in a hot and thermo-neutral environment. Using a randomized, cross-over design, 14 participants completed two identical ~20-minute yoga sessions in a hot (35.3 ± 0.8°C; humidity: 20.5 ± 1.4%) and thermo-neutral (22.1 ± 0.2°C; humidity: 27.8 ± 1.6%) environment. Oxygen consumption (VO<sub>2</sub>) and heart rate (HR) were recorded as objective measures (%VO<sub>2</sub>max and %HRmax) and rating of perceived exertion (RPE) was recorded as a subjective measure of exercise intensity. There was no difference in exercise intensity based on %VO<sub>2</sub>max during hot vs. thermo-neutral yoga (30.9 ± 2.3 vs. 30.5 ± 1.8%, p=0.68). However, exercise intensity was significantly higher during hot vs. thermo-neutral yoga based on %HRmax (67.0 ± 2.3 vs. 60.8 ± 1.9%, p=0.01) and RPE (12 ± 1 vs. 11 ± 1, p=0.04). According to established exercise intensities, hot yoga was classified as "light-intensity" based on %VO<sub>2</sub> but "moderate-intensity" exercise based on %HRmax and RPE while thermo-neutral yoga was classified as "light-intensity" exercise based on %VO<sub>2</sub>max, %HRmax, and RPE. Despite the added hemodynamic stress and perception that yoga is more strenuous in a hot environment, we observed similar oxygen consumption during hot vs. thermo-neutral yoga classifying both exercise modalities as "light-intensity" exercise.
PMID: 29169011 [PubMed - as supplied by publisher]
The effects of yoga on stress and psychological health among employees: an 8- and 16-week intervention study.
Anxiety Stress Coping. 2017 Nov 23;:1-14
Authors: Maddux RE, Daukantaité D, Tellhed U
BACKGROUND: The stresses of modern work life necessitate effective coping strategies that are accessible and affordable to the general public. Yoga has been found to reduce stress in clinical samples, but studies are needed to examine standard gym yoga classes among functional individuals.
OBJECTIVES: This study investigated the effects of 8- and 16-week gym yoga on stress and psychological health.
DESIGN AND METHOD: Ninety individuals reporting moderate-to-high stress were randomly assigned to 16 consecutive weeks of yoga, or to a waitlist crossover group who did not practice yoga for 8 weeks then practiced yoga for 8 weeks. Stress and psychological health variables were assessed at baseline, 8 weeks, and 16 weeks.
RESULTS: Significant reductions in stress and all psychological health measures were found within the Yoga group over 16 weeks. When compared to the control group, yoga practitioners showed significant decreases in stress, anxiety, and general psychological health, and significant increases in well-being. The group who did not practice yoga showed significant decreases in stress, anxiety, depression, and insomnia after they crossed over and practiced yoga for 8 weeks.
CONCLUSIONS: Gym yoga appears to be effective for stress amelioration and promotion of psychological health among workers experiencing stress.
PMID: 29166771 [PubMed - as supplied by publisher]