Background:Surya Namaskar (SN), a popular traditional Indian yogic practice, includes practicing 12 physical postures with alternate forward and backward bending movement of the body along with deep breathing maneuvers. The practice of SN has become popular among yoga practitioners and other fitness conscious people. The long-term effect of practicing SN and other yogic practices on cardiorespiratory responses during SN are lacking.Aim:The present study was conducted to study the effect of yogic training on various cardiorespiratory responses during the SN practice in yoga trainees after a time interval of 3, 6, and 11 months.Materials and Methods:The present study was conducted on 9 healthy male Army soldiers who underwent training in various yoga postures including SN, meditation, and pranayama for 1 h daily for 11 months. First, second, and third phase of the study was conducted in the laboratory after completion of 3, 6, and 11 months of the yoga training. The participants performed SN along with other yogic practices in the laboratory as per their daily practice schedule. The cardiorespiratory responses of the volunteers were recorded during actual practice of SN.Statistical Analysis:One-way repeated measure ANOVA followed by Tukey HSD.Results:Oxygen consumption and heart rate during actual practice of SN was 0.794 ± 0.252, 0.738 ± 0.229, and 0.560 ± 0.165 L/min and 92.1 ± 11.6, 97.9 ± 7.3 and 87.4 ± 9.2 beats/min respectively at 1st , 2nd , and 3rd phase of yoga training. Minute ventilation and tidal volume also reduced from 19.9 ± 4.65 to 17.8 ± 4.41 L/min and 1.091 ± 0.021 to 0.952 L/breath from 1st phase to 3rd phase of yoga training. However, respiratory parameters like breathing rate (fR) did not show any reduction across the three phases.Conclusion:The results of the present study indicated that yogic training caused conditioning of cardiorespiratory parameters except fR, which did not reduce across three phases of training.

The present case study described the modulation of cardiovascular functions of a healthy male during CPT, which finally led to the development of neurocardiogenic syncope characterized by hypotension and bradycardia.

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Introduction: Optimal cognitive performance is the essence of effective execution of a flying mission. Effects of two commonly encountered aviation stressors, hypoxia and noise, on performance have been studied. However, studies on effects of concurrent dual effects of both these stressors on key cognitive parameters are sparse; hence, the objective was to examine these effects. Material and Methods: Cognitive performances were assessed among 30 healthy volunteers (28 males and 2 females) sequentially in four different conditions – baseline (without stressors), 85 dB(A) noise, 14,000 ft altitude, and concurrent exposure to 85 dB(A) noise at 14,000 ft altitude. White noise was simulated through software, altitude in the hypobaric chamber and cognitive performance was assessed with tests from Psychology Experiment Building Language (PEBL) test battery. Data were analyzed using descriptive statistics and repeated measures ANOVA. Results: The study revealed statistically significant direct detrimental effect of altitude and noise on implicit reaction time independently as well as concurrently. However, there was insignificant interaction effect between the dual stressors on implicit reaction time. There were no statistically significant effects of dual stressors on implicit correctness, visuospatial working memory, and selective attention. Although statistically not significant, noise enhanced the performance level in the form of increased Corsi block memory span and Corsi block total score. Conclusion: No significant effect of the dual stressors was observed on most of the cognitive parameters. However, implicit reaction time, a measure of pilot’s risk-taking behavior, was found to be significantly affected by the dual stressors. Further research with a larger sample of aircrew population who differ in age, experience, and other potentially influencing factors is recommended.

Introduction: Human morphology and physiology are not designed inherently to function in microgravity. Hence, exposure to hypo or microgravity, as it occurs during space exploration, poses challenges in the form of peculiar adaptive physiological processes in healthy astronauts. These changes may vary (to a certain extent) depending on type of physical fitness (namely, aerobic or anaerobic) and may have definitive impact on short duration space mission. The study aimed to examine the cardiovascular dynamics during short duration exposure to simulated microgravity condition in differently trained individuals. Material and Methods: Temporal variations in body fluid distribution were studied during 6° head-down tilt (HDT) for 4-hours in 31 healthy males in age range of 20–40 years divided into three groups based on their physical training, namely; resistance trained (RT), endurance trained (ET), and untrained (UT). This was based on their history of physical training, VO2 max, and peak anaerobic power. Results: Heart rate in the ET group and RT group showed increasing and decreasing trend respectively, however, statistically remained non-significant. Systolic and diastolic pressures showed a significant increase in the ET group at the 4th h of HDT as compared to baseline and the 1st h. No significant variation in pulse pressure could be seen. Mean arterial pressures showed significant increase in the ET group at the 4th h of HDT as compared to baseline and the 1st h of HDT. Stroke volume and cardiac output did not vary significantly. Conclusion: ET individuals in the present study demonstrated decreased sensitivity of baroreceptors than RT or UT individuals, whereas, the RT group demonstrated more stability/resilience in terms of cardiovascular dynamics than ET and UT groups under exposure to short duration simulated microgravity.