Metabolic Energy Contributions During High-Intensity Hatha Yoga and Physiological Comparisons Between Active and Passive (Savasana) Recovery.

Purpose: The objective of this study was to investigate metabolic energy contributions during high-intensity hatha yoga (HIHY) and to compare changes in physiological variables between active and passive recovery methods. Methods: The study involved 20 women yoga instructors (n = 20) who performed 10 min of HIHY (vigorous sun salutation). Upon completion, they were randomly assigned to either active (walking; n = 10) or passive (savasana; n = 10) recovery groups for a period of 10 min. During HIHY, physiological variables such as heart rate (HRpeak and HRmean), oxygen uptake (VO2peak and VO2mean), and blood lactate concentrations (peak La-) were measured. Energetic contributions (phosphagen; WPCR, glycolytic; WGly, and oxidative; WOxi) in kJ and % were estimated using VO2 and La- data. Furthermore, the metabolic equivalents (METs) of VO2peak and VO2mean were calculated. To compare different recovery modes, HRpost, ΔHR, VO2post, ΔVO2, recovery La-, and recovery ΔLa- were analyzed. Results: The results revealed that HRpeak, VO2peak, and peak La- during HIHY showed no differences between the two groups (p > 0.05). Values of HRpeak, HRmean, METs of VO2peak and VO2mean, and La- during HIHY were 95.6% of HRmax, 88.7% of HRmax, 10.54 ± 1.18, 8.67 ±.98 METs, and 8.31 ± 2.18 mmol·L-1, respectively. Furthermore, WOxi was significantly higher compared with WPCR, WGly, and anaerobic contribution (WPCR + WGly), in kJ and % (p < 0.0001). VO2post and recovery ΔLa- were significantly higher in the active recovery group (p < 0.0001, p = 0.0369, respectively). Values of ΔVO2 and recovery La- were significantly lower in the active group compared with the passive group (p = 0.0115, p = 0.0291, respectively). Conclusions: The study concluded that high-intensity hatha yoga which was performed for 10 min is a suitable option for relatively healthy people in the modern workplace who may have hatha yoga experience but do not have time to perform a prolonged exercise. Following active recovery, they can participate in further HIHY sessions during short breaks. Furthermore, a faster return to work can be supported by physiological recovery.

Effects of Individualized Low-Intensity Exercise and Its Duration on Recovery Ability in Adults.

Exercise is recommended to increase physical health and performance. However, it is unclear how low-intensity exercise (LIE) of different durations may affect or improve recovery ability. This study aimed to investigate how LIE-duration with the same volume affects recovery ability in adults. Twenty healthy male adults participated in this study. Participants were randomly assigned to the 30-min (n = 10) or the 1-h LIE group (n = 10). The intervention included sixteen exercise sessions/four weeks with a 30-min LIE group, and eight exercise sessions/four weeks with a 1-h LIE group. Heart rate (HR) corresponding to <2 mmol∙L-1 blood lactate (La-) was controlled for LIE. Pre- and post-testing was conducted before and after 4-week LIE and tests included jogging/running speed (S), HR, and differences (delta; ∆) in HR and S between pre- and post-testing at 1.5, 2.0, and 4.0 mmol∙L-1 La-. Only the HR at 2.0 mmol∙L-1 La- of the 30-min LIE group was decreased in the post-test compared to the pre-test (p = 0.043). The jogging/running speed of the 1-h LIE group was improved in the post-test compared to the pre-test (p < 0.001, p = 0.006, p = 0.002, respectively). ∆HR at 2.0 and ∆S between the 30-min and 1-h LIE group at 1.5, 2.0, and 4.0 mmol∙L-1 La- were significantly different (p = 0.023, p < 0.001, p = 0.002, and p = 0.019, respectively). Furthermore, moderate to high positive correlations between ∆HR and ∆S of all subjects at 1.5 (r = 0.77), 2.0 (r = 0.77), and 4.0 (r = 0.64) mmol∙L-1 La- were observed. The 1-h LIE group showed improved endurance not only in the low-intensity exercise domain, but also in the beginning of the moderate to high-intensity exercise domain while the 30-min LIE group was not affected by the 4-week LIE intervention. Therefore, LIE (<2.0 mmol∙L-1) for at least 1-h, twice a week, for 4 weeks is suggested to improve recovery ability in adults.