Surya Namaskar: As an Alternative for Aerobic Fitness.

Context: "Surya Namaskar" (SN) may be used as a need-based short-duration aerobic activity in a confined space to establish as a substitute of an equivalent routine physical training in challenging stressful conditions. Materials and Methods: Noninvasive oxygen-kinetics metabolic responses between SN and endurance work on bicycle ergometry (BE) were compared across different phases of maximal oxygen uptake percentage (%VO2 max). SN, comprising three complete rounds per min (36 beats/min of a metronome; SN consists of 12 poses per round), was performed rhythmically and continuously for 5 min to simulate an incremental BE test (25 watts/2 min at 60 rpm). Results: SN results in a significant (P < 0.05) greater increase of arteriovenous oxygen difference at 71%-80% VO2 max while keeping a low respiratory exchange ratio (P < 0.01 and 0.001) at 41%-80% VO2 max exercising state. Conclusions: SN could be an ideal form of aerobic exercise instead of BE.

Improvement in resilience and stress-related blood markers following ten months yoga practice in Antarctica.

BACKGROUND: Wintering is associated with distress to humans who work in the isolated and confined environment of Antarctica and yoga has been proved helpful for coping with stress. Therefore, a study was conducted on 14 winter expedition members of Indian Scientific Antarctic Expedition (2016) to find out the effects of yoga on stress-related markers. METHODS: Participants were divided into yoga, and control (non-yoga) groups. The yoga group practiced yoga for 10 months (from January to October 2016) daily in the morning for an hour. The Resilience test questionnaire was administrated at baseline and endpoint of the study. Blood samples were collected during the study at different intervals for the estimation of 8-hydroxydeoxyguanosine (8-OHdG), brain-derived neurotrophic factor (BDNF), serotonin and cortisol using ELISA. RESULTS: A trend of improvement was observed in the resilience test score in the yoga group. From January to October, 8-OHdG serum values in the yoga group declined by 55.9% from 1010.0 ± 67.8 pg/mL to 445.6 ± 60.5 pg/mL (Mean ± SD); in the control group, the decline was 49.9% from 1060.4 ± 54.6 pg/mL to 531.1 ± 81.8 pg/mL. In serotonin serum levels in the yoga group, there was a 3.1% increase from 6.4 ± 1.6 ng/mL to 6.6 ± 0.4 ng/mL while no increase was noticed in the control group. Cortisol values in the yoga group decreased by 19.9% from 321.0 ± 189.6 ng/mL to 257.1 ± 133.8 ng/mL; in the control group it increased by 2.8% from 241.2 ± 51.8 ng/mL to 247.8 ± 90.9 ng/mL. CONCLUSIONS: It could be concluded from the present study that following 10 months yoga practice may be useful for better resilience and management of stress-related blood markers for the polar sojourners.

Comparison of cardiorespiratory responses between Surya Namaskar and bicycle exercise at similar energy expenditure level.

Surya Namaskar (SN), a popular traditional Indian yogic practice called "Sun Salutations", includes practice of twelve physical postures involving alternate backward bending and forward bending postures. The practice of twelve postures in succession makes one round of its practice. Many people practise it as part of their daily physical fitness regimen. No study is available to compare cardiorespiratory responses of SN with bicycle exercise (BE). 20 healthy Yoga instructors practicing various Yogic practices including SN since last 7-8 years participated in the study. They performed SN in the laboratory according to their customary daily practice routine. The subject also performed incremental load bicycle exercise test till exhaustion on their second visit for measuring their VO2 max. SN and BE were compared at three similar exercise intensity levels in terms of % of VO2 max. The exercise intensities were light (10-20% VO2 max), moderate (21-40% VO2 max) and high intensities (41-50% VO2 max). Heart rate at high work intensity was significantly higher in BE than SN (P < .001). Ventilation and carbon dioxide output were significantly higher in BE than SN at high exercise intensity (P < 0.001). Overall, cardiorespiratory stress is less in SN than BE at similar work intensities.

Hatha yoga practices: energy expenditure, respiratory changes and intensity of exercise.

The aim of this study was to critically observe the energy expenditure, exercise intensity and respiratory changes during a full yoga practice session. Oxygen consumption ([Formula: see text]), carbon dioxide output ([Formula: see text]), pulmonary ventilation ([Formula: see text]E), respiratory rate (Fr) and tidal volume (VT), were measured in 16 physical posture (asanas), five yoga breathing maneuvers (BM) and two types of meditation. Twenty male (age 27.3 ± 3.5 years, height 166.6 ± 5.4 cm and body weight 58.8 ± 9.6 kg) yoga instructors were studied. Their maximal oxygen consumption ([Formula: see text]) was recorded. The exercise intensity in asanas was expressed in percentage [Formula: see text] . In asanas, exercise intensity varied from 9.9 to 26.5% of [Formula: see text] . Highest energy cost was 3.02 kcal min(-1). In BM highest [Formula: see text]E was 53.7 ± 15.5 l min(-1). VT was 0.97 ± 0.59, 1.41 ± 1.27 and 1.28 ± l/breath with corresponding Fr of 14.0 ± 5.3, 10.0 ± 6.35, 10.0 ± 5.8 breaths/min. Average energy expenditure in asanas, BM and meditation were 2.29, 1.91 and 1.37 kcal min(-1), respectively. Metabolic rate was generally in the range of 1-2 metabolic equivalents (MET) except in three asanas where it was >2 MET. [Formula: see text] was 0.27 ± 0.05 and 0.24 ± 0.04 l min(-1) in meditation and Shavasana, respectively. Although yogic practices are low intensity exercises within lactate threshold, physical performance improvement is possible owing to both better economy of breathing by BM and also by improvement in cardiovascular reserve. Other factors such as psycho-physiological and better relaxation may contribute to it.