Abstract We summarize and elaborate on the challenges of researching in the field of human health in Antarctica based on the conceptual and methodological specificities of a line of investigation that aims to study the human presence in Antarctica in all of its dimensions (biological, psychological, and socio-anthropological). Herein, we discuss the principal results and limitations of the research carried out by researchers of MEDIANTAR (Antarctic medicine, physiology, and anthropology) group of Programa Antártico Brasileiro in isolated, confined, and extreme environments over the last six years. Fieldwork has been carried out in remote research camps, Brazilian navy ships (Almirante Maximiano/H-41 and Ary Rongel/H-44), and Comandante Ferraz Antarctic Station. Adaptative responses to isolated, confined, and extreme environments were studied based on questionnaires, interviews, participative observation, biological samples, anthropometric, and physiological parameters. Our researchers face the unique situation of concomitantly working under the stressful living conditions that are the object of their investigation. A critical examination of the socio-methodological characteristics and challenges of this research niche indicates the need for exchanging the lessons learned and limitations of these practices with researchers in the humanities field, with attention to the human resources needs in multidisciplinary human-related studies.

Abstract We evaluated the influence of a 32-day camping in Antarctica on physical performance and exercise-induced thermoregulatory responses. In Brazil, before and after the Antarctic camping, the volunteers performed an incremental exercise at temperate conditions and, two days later, an exercise heat stress protocol (45-min running at 60% of maximum aerobic speed, at 31°C and 60% of relative humidity). In Antarctica, core temperature was assessed on a day of fieldwork, and average values higher than 38.5°C were reported. At pre- and post-Antarctica, physiological (whole-body and local sweat rate, number of active sweat glands, sweat gland output, core and skin temperatures) and perceptual (thermal comfort and sensation) variables were measured. The Antarctic camping improved the participants’ performance and induced heat-related adaptations, as evidenced by sweat redistribution (lower in the chest but higher in grouped data from the forehead, forearm, and thigh) and reduced skin temperatures in the forehead and chest during the exercise heat stress protocol. Notwithstanding the acclimatization, the participants did not report differences of the thermal sensation and comfort. In conclusion, staying in an Antarctic camp for 32 days improved physical performance and elicited physiological adaptations to heat due to the physical exertion-induced hyperthermia in the field.

Abstract Open-water diving in a polar environment is a psychophysiological challenge to the human organism. We evaluated the effect of short-term diving (i.e., 10 min) in Antarctic waters on autonomic cardiac control, thyroid hormone concentration, body temperatures, mood, and neuropsychological responses (working memory and sleepiness). Data collection was carried out at baseline, before, and after diving in four individuals divided into the supporting (n=2) and diving (n=2) groups. In the latter group, autonomic cardiac control (by measuring heart rate variability) was also assessed during diving. Diving decreased thyroid-stimulating hormone (effect size = 1.6) and thyroxine (effect size = 2.1) concentrations; these responses were not observed for the supporting group. Diving also reduced both the parasympathetic (effect size = 2.6) and sympathetic activities to the heart (ES > 3.0). Besides, diving reduced auricular (effect size > 3.0), skin [i.e., hand (effect size = 1.2) and face (effect size = 1.5)] temperatures compared to pre-dive and reduced sleepiness state (effect size = 1.3) compared to basal, without changing performance in the working memory test. In conclusion, short-term diving in icy waters affects the hypothalamic-pituitary-thyroid axis, modulates autonomic cardiac control, and reduces body temperature, which seems to decrease sleepiness.

ABSTRACT Background: Children and adolescents with at-risk genotypes (AA/AT) of the rs9939609 polymorphism in FTO, a fat mass and obesity-associated gene, may exhibit different cardiometabolic profile responses than subjects with the TT genotype after an interdisciplinary intervention. Methods: The sample consisted of 36 school children from southern Brazil. We used DNA quantitation and real-time polymerase chain reaction (PCR) for polymorphism genotyping. We measured anthropometric parameters (body mass index (BMI), waist circumference, hip circumference, waist-hip ratio, body fat percentage and skinfold sum), biochemical parameters (glucose, lipid profile, ultra-sensitive C-reactive protein, uric acid, alanine aminotransferase, aspartate aminotransferase, insulin and adiponectin) and blood pressure. The 4-month intervention consisted of physical education classes, nutritional counseling, and postural and oral health counseling. Results: We observed no significant differences among the groups (AA, AT and TT) after the intervention. However, we observed improvements in three parameters (waist circumference, hip circumference and C-reactive protein) in the AT/AA genotype group and in two parameters (hip circumference and uric acid) in the TT genotype group. Conclusions: After an intervention program, carriers of at-risk genotypes for obesity (AA/AT) do not exhibit differences in biochemical parameters, blood pressure and anthropometric parameters compared with carriers of the TT genotype.