Abstract Introduction: Stress is a contemporary phenomenon that affects the world population and university students, this factor could be one of those involved in the quality of sleep, which is important to take care of, especially in students because of its relevance in the learning process, and on the other hand physical activity can affect both how to manage stress levels or prevent sleep disorders, which is why this study aims to relate stress levels with sleep quality and physical activity in medical students. Methods: A descriptive, correlational, and cross-sectional study was developed based on different studies. the responses of 116 Medicine students from the University of Magallanes were analyzed using three evaluations: The perceived Stress Scale, the International Physical Activity Questionnaire (IPAQ), and the Pittsburgh Test). Results: Medicine students presented a positive correlation (p=0.64, p<0.001) between the Perceived Stress Scale (PSS) and Pittsburgh (Pitts). One of the PSS variables (unable to control things) and the student's dysfunction in performing their essential daily tasks (dysfunction during the day) have a positive correlation (p=0.54, p<0.001). Physical activity averaged 930 METs, and no significant correlation was found with the PSS and Pitts variables. Conclusion: The relationship between stress and sleep quality is inversely proportional; therefore, the higher the level of stress perceived, the lower the student's sleep quality, which is not related.

Resumen Introducción: el estrés es un fenómeno contemporáneo que afecta a la población mundial y a los estudiantes universitarios, este factor pudiese ser uno de los que interviene en la calidad de sueño, la cual es importante de cuidar sobre todo en los alumnos debido a su relevancia en el proceso de aprendizaje, y por otro lado la actividad física puede afectar tanto en cómo manejar los niveles de estrés o prevenir trastornos del sueño, es por ello que este estudio tiene como objetivo relacionar los niveles de estrés con la calidad del sueño y la actividad física en estudiantes de medicina. Métodos: se desarrolló un estudio descriptivo, correlacional y transversal basado en diferentes estudios. Se analizaron las respuestas de 116 estudiantes de Medicina de la Universidad de Magallanes mediante tres evaluaciones: Escala de Estrés Percibido, Cuestionario Internacional de Actividad Física (IPAQ) y Test de Pittsburgh. Resultados: los estudiantes de Medicina presentaron una correlación positiva (p=0.4, p<0.001) entre la Escala de Estrés Percibido (EEP) y la de Pittsburgh (Pitts). Una de las variables EEP (incapaz de controlar las cosas) y la disfunción del estudiante en la realización de sus tareas esenciales diarias (disfunción durante el día) tienen una correlación positiva (p=0.54, p<0.001). La actividad física tuvo un promedio de 930 MET's, y no se encontró correlación significativa con las variables EEP y Pitts. Conclusión: la relación entre el estrés y la calidad del sueño es inversamente proporcional; por lo tanto, a mayor nivel de estrés percibido, menor calidad de sueño del estudiante, lo cual no está relacionado.

Abstract: Objective: To functionally characterize patients with Cerebral Palsy (CP) living in the Magallanes Re gion and the Chilean Antarctic. Patient and Method: Descriptive-retrospective observational study of patients with cerebral palsy, registered in the Outpatient Rehabilitation Program of the Corporación de Rehabilitación Club de Leones Cruz del Sur de Punta Arenas between 1986 and 2018. Patients with CP were clinically categorized and then functionally characterized according to gross motor skills (GMFCS), manual ability (MACS), feeding ability (EDACS), and communication function (CFCS). Results: 106 patients were included. Regarding the clinical classification, the most common type of CP was bilateral spastic paralysis, with the highest percentage of functional involvement in each of the evaluated areas, followed by unilateral spastic paralysis, while cases of dystonic CP and other non-classifiable types presented were less frequent. According to the clinical subclassification, spastic diplegia was more frequent, especially affecting manual and communication skills level I compared with hemiplegia, while cases of mixed and unclassifiable quadriplegia were less frequent with greater overall involvement of level I feeding skills. Conclusion: The observed results of CP in the Magalla nes Region and the Chilean Antarctic are similar to studies available in the literature. The complete evaluation and classification of patients with CP enable a better understanding of the pathology for future studies.

Resumen: Objetivo: Caracterizar funcionalmente a pacientes con Parálisis Cerebral (PC) que viven en la región de Magallanes y la Antártica Chilena. Pacientes y Método: Estudio observacional descriptivo-retros- pectivo de pacientes con parálisis cerebral, registrados en el Programa de Rehabilitación Ambulatorio de la Corporación de Rehabilitación Club de Leones Cruz del Sur de Punta Arenas entre los años 1986 y 2018. Los pacientes con PC se categorizaron clínicamente, y posteriormente se caracterizaron funcionalmente en base a sistemas de clasificación de habilidades motoras (escala GMFCS), ma nuales (escala MACS), alimentación (escala EDACS) y comunicación (escala CFCS). Resultados: Se incluyeron 106 pacientes con PC. En relación con la clasificación clínica, el tipo más común de PC fue la parálisis espástica bilateral, quienes también presentan el mayor porcentaje de compromiso de funcional en cada una de las áreas evaluada, seguido por la parálisis espástica unilateral. Los casos de PC distónica y otros tipos no clasificables presentaron menor frecuencia de casos. En base a la sub- clasificación clínica diagnóstica, la mayor frecuencia detectada fue la diplejia espástica, concentrando el compromiso funcional especialmente en las habilidades manuales y de comunicación de nivel I en comparación a la hemiplejia. En el caso de cuadriplejia, mixta y no clasificable, presentan menor frecuencia de casos, con un mayor compromiso general en las habilidades de alimentación en nivel I. Conclusión: Los resultados observados de la PC en la región de Magallanes y la Antártica Chilena son similares a estudios disponibles en la literatura. La completa evaluación y clasificación de pacientes con PC posibilita una mayor comprensión de la patología para futuros estudios.

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 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.

Resumen Introducción: En la actualidad, los entrenadores buscan la manera de mejorar las capacidades físicas de los atletas mediante diferentes estrategias de entrenamiento, como la exposición constante o intermitente a la altitud y el entrenamiento de intervalos de alta intensidad. Objetivo: Revisar la literatura actual y describir los efectos sobre el organismo del entrenamiento de intervalos de alta intensidad en altitud simulada en sujetos sedentarios, físicamente activos y entrenados. Resultados: El número de artículos revisados evidencia que, en hipoxia simulada en cámara hipobárica o normobárica (n=13) o máscara de simulación de altitud (n=1), todos utilizaron intensidades altas (n=13) a submáximas (n=1). Los participantes de las investigaciones fueron mujeres con obesidad sedentarias (n=3), hombres y mujeres físicamente activos (n=9) y sujetos entrenados (n=3). El tiempo de intervención de los estudios fue de 3 a 12 semanas, con una altitud simulada de 1824 a 4500 m.s.n.m. Se observaron efectos beneficiosos sobre la composición corporal, aptitud cardiorrespiratoria, aumentos en hemoglobina, eritropoyetina, consumo energético, fuerza máxima concéntrica e isométrica, fuerza absoluta y mejor tolerancia al ejercicio (percepción del esfuerzo). Conclusiones: La combinación de entrenamientos de intervalos de alta intensidad, combinado con una exposición en altitud simulada, puede evidenciar mejoras significativas en el rendimiento cardiorrespiratorio, así como en aspectos de composición corporal, lo que permitiría una mejor predisposición a intensidades más elevadas de actividad y ejercicio físico.

Abstract Introduction: Today, coaches are looking for ways to improve athletes' physical abilities through different training strategies, such as constant or intermittent exposure to altitude and high intensity interval training. Objective: To review the current literature and describe the effects on the body of simulated high-intensity interval training at altitude in sedentary, physically active, and trained subjects. Results: The number of articles reviewed evidences that, in simulated hypoxia in hypobaric or normobaric chamber (n = 13) or altitude simulation mask (n = 1), all used high intensities (n = 13) to submaximal (n = 1). The research participants were women with sedentary obesity (n = 3), physically active men and women (n = 9), and trained subjects (n = 3). The intervention time of the studies was 3 to 12 weeks, with a simulated altitude of 1824 to 4500 meters. Beneficial effects on body composition were observed, as well as cardiorespiratory fitness, increases in hemoglobin, erythropoietin, energy consumption, concentric and isometric maximum strength, absolute strength and better exercise tolerance (perception of effort). Conclusions: The combination of high intensity interval training combined with a simulated altitude exposure can show significant improvements in cardiorespiratory performance, as well as in aspects of body composition, which would allow a better predisposition to higher intensities of activity and physical exercise.

Background: There is no evidence for the association of depressive symptoms with the sense of well-being of undergraduate medical students residing in high southern latitudes (HSL). Aim: To assess the frequency of depressive symptoms and its relationship with seasonal sensitivity and quality of life in medical students residing in HSL. Material and Methods: The Beck anxiety and depressive symptoms inventory, the seasonal pattern assessment questionnaire and the quality-of-life questionnaire of the WHO were applied to 102 medical students residing in Magallanes, Chile. Results: Fifty-two percent of respondents reported some degree of depressive symptoms. These symptoms were significantly associated with the seasonal pattern score (r = 0.432, p < 0.01). They were also inversely associated with parameters of physical health and psychosocial health (r = −0.567, p < 0.01 and r = −0.708, p < 0.01, respectively). There was also a correlation between depressive and anxiety symptoms. Conclusions: Depressive symptoms are common in medical students residing in HSL and they are associated with seasonal sensitivity and quality of life measures.