Reduced running performance and greater perceived exertion, but similar post-exercise neuromuscular fatigue in tropical natives subjected to a 10 km self-paced run in a hot compared to a temperate environment.

Environmental heat stress impairs endurance performance by enhancing exercise-induced physiological and perceptual responses. However, the time course of these responses during self-paced running, particularly when comparing hot and temperate conditions, still needs further clarification. Moreover, monitoring fatigue induced by exercise is paramount to prescribing training and recovery adequately, but investigations on the effects of a hot environment on post-exercise neuromuscular fatigue are scarce. This study compared the time course of physiological and perceptual responses during a 10 km self-paced treadmill run (as fast as possible) between temperate (25°C) and hot (35°C) conditions. We also investigated the changes in countermovement jump (CMJ) performance following exercise in these two ambient temperatures. Thirteen recreational long-distance runners (11 men and 2 women), inhabitants of a tropical region, completed the two experimental trials in a randomized order. Compared to 25°C, participants had transiently higher body core temperature (TCORE) and consistently greater perceived exertion while running at 35°C (p < 0.05). These changes were associated with a slower pace, evidenced by an additional 14 ± 5 min (mean ± SD) to complete the 10 km at 35°C than at 25°C (p < 0.05). Before, immediately after, and 1 h after the self-paced run, the participants performed CMJs to evaluate lower limb neuromuscular fatigue. CMJ height was reduced by 7.0% (2.3 ± 2.4 cm) at 1 h after the race (p < 0.05) compared to pre-exercise values; environmental conditions did not influence this reduction. In conclusion, despite the reduced endurance performance, higher perceived exertion, and transiently augmented TCORE caused by environmental heat stress, post-exercise neuromuscular fatigue is similar between temperate and hot conditions. This finding suggests that the higher external load (faster speed) at 25°C compensates for the effects of more significant perceptual responses at 35°C in inducing neuromuscular fatigue.

Cardiac autonomic modulation response and functional capacity in older women / Respuesta de la modulación autonómica cardíaca y capacidad funcional en mujeres mayores / Resposta da modulação autonômica cardíaca e capacidade funcional em mulheres idosas

ABSTRACT Objective: To analyze cardiac autonomic modulation response and functional capacity in physically active older women. Methods: Seventy-five older women (60-70 years) from the community were divided into the following groups: sedentary (n=19), hydro-gymnastics (n=18), pilates (n=19), and dance (n=19). Blood pressure, body composition, heart rate variability, and functional capacity were assessed for the characterization of the groups at rest and 48 hours after the last physical exercise session. Results: The sedentary group presented higher waist-to-hip ratio, diastolic blood pressure, and resting heart rate compared to the other groups (p<0.05). It was also observed that the dance group presented better functional capacity and VO2peak scores (all p<0.05). Regarding cardiac autonomic modulation, both dance and pilates groups demonstrated better RMSSD (26.71 ± 9.07 and 29.82 ± 7.16, respectively; p<0.05), LF (45.79 ± 14.81 and 45.95 ± 15.16 n.u., respectively; p<0.05), and LF/HF (0.92 ± 0.56 and 0.58 ± 0.26, respectively; p<0.05) scores. In the symbolic analysis, the dance group had a greater predominance of parasympathetic autonomic modulation than the other groups (p<0.05). Conclusion: These results conclude that physically active elderly women, practicing hydro-gymnastics, pilates or dance, presented physiological benefits, such as better functional capacity and improvements in hemodynamic variables and autonomic cardiac modulation. In addition, the group that practiced dance presented greater parasympathetic modulation, as well as greater functional capacity, when compared to the other modalities. Level of evidence: I; STARD: studies of diagnostic accuracy.

RESUMEN Objetivo: Analizar la respuesta de la modulación autonómica cardíaca y la capacidad funcional en mujeres mayores físicamente activas. Métodos: Setenta y cinco mujeres mayores (60 a 70 años) de la comunidad fueron divididas en los siguientes grupos: sedentaria (n = 19), hidrogimnasia (n = 18), pilates (n = 19) y danza (n = 19). La presión arterial, la composición corporal, la variabilidad de la frecuencia cardíaca y la capacidad funcional fueron evaluadas para la caracterización de los grupos en reposo y 48 horas después de la última sesión de ejercicio físico. Resultados: El grupo sedentario presentó mayor relación cintura-cadera, presión arterial diastólica y frecuencia cardíaca en reposo cuando comparado a los otros grupos (p <0,05). Se observó que el grupo de danza presentó mejores puntajes de capacidad funcional y VO2Pico (todos p <0,05). Con relación a la modulación autonómica cardíaca, los grupos de danza y pilates demostraron mejores puntajes para RMSSD (26,71 ± 9,07 y 29,82 ± 7,16, respectivamente; p <0,05), LF (45,79 ± 14,81 y 45,95 ± 15,16 nu, respectivamente; p <0,05), y LF/HF (0,92 ± 0,56 y 0,58 ± 0,26, respectivamente; p <0,05). En el análisis simbólico, el grupo de danza presentó mayor predominancia de la modulación autonómica parasimpática que los demás grupos (p <0,05). Conclusión: Esos resultados concluyen que las mujeres mayores físicamente activas, practicantes de hidrogimnasia, pilates o danza, tienen beneficios fisiológicos, como mejor capacidad funcional y mejora de las variables hemodinámicas y de la modulación cardíaca autonómica. Además, el grupo que practicaba danza tuvo mayor modulación parasimpática y mayor capacidad funcional cuando comparado con las otras modalidades. Nivel de evidencia: I; STARD: estudios de precisión diagnóstica.

RESUMO Objetivo: Analisar a resposta da modulação autonômica cardíaca e a capacidade funcional em idosas fisicamente ativas. Métodos: Setenta e cinco mulheres idosas (60 a 70 anos) da comunidade foram divididas nos seguintes grupos: sedentária (n = 19), hidroginástica (n = 18), pilates (n = 19) e dança (n = 19). A pressão arterial, a composição corporal, a variabilidade da frequência cardíaca e a capacidade funcional foram avaliadas para a caracterização dos grupos em repouso e 48 horas depois da última sessão de exercício físico. Resultados: O grupo sedentário apresentou maior relação cintura-quadril, pressão arterial diastólica e frequência cardíaca em repouso quando comparado aos outros grupos (p <0,05). Observou-se também que o grupo da dança apresentou melhores escores de capacidade funcional e VO2pico (todos p < 0,05). Com relação à modulação autonômica cardíaca, os grupos de dança e pilates demonstraram melhores escores para RMSSD (26,71 ± 9,07 e 29,82 ± 7,16, respectivamente; p < 0,05), LF (45,79 ± 14,81 e 45,95 ± 15,16 nu, respectivamente; p<0,05) e LF/HF (0,92 ± 0,56 e 0,58 ± 0,26, respectivamente; p < 0,05). Na análise simbólica, o grupo da dança apresentou maior predominância da modulação autonômica parassimpática do que os demais grupos (p < 0,05). Conclusão: Esses resultados concluem que idosas fisicamente ativas praticantes de hidroginástica, pilates ou dança, têm benefícios fisiológicos, como melhor capacidade funcional e melhora das variáveis hemodinâmicas e da modulação cardíaca autonômica. Além disso, o grupo que praticava dança teve maior modulação parassimpática e maior capacidade funcional quando comparado com outras modalidades. Nível de evidência: I; STARD: estudos de precisão diagnóstica.

Short-term combined exercise training improves cardiorespiratory fitness and autonomic modulation in cancer patients receiving adjuvant therapy.

The present study aimed to investigate the impact of a short-term exercise training (ET) on the cardiorespiratory fitness and autonomic modulation of women with breast cancer who were receiving adjuvant radiotherapy, chemotherapy or hormonotherapy. Eighteen women previously diagnosed with breast cancer receiving adjuvant radiotherapy, chemotherapy or hormone therapy were randomly allocated into breast cancer nonexercise (BC) and exercise groups (BC+Ex). Moreover, nine healthy physically inactive volunteers were recruited to compose the noncancer control group (CG). The BC+Ex group was underwent to a combined ET program, which was based on resistance, aerobic and flexibility exercises. ET was performed 3 times a week, on nonconsecutive days, for 4 weeks at the hospital room under the professional supervision. In turn, BC and CG remained without be engaged in physical exercise programs. Volunteers were evaluated regarding their cardiorespiratory fitness and autonomic modulation (i.e., time, frequency domains, and nonlinear [symbolic analysis]) before and after the end of the ET program. A priori, data indicate that women patients with breast cancer showed impaired exercise tolerance, as well as autonomic dysfunction in comparison with age-matched healthy control subjects. However, a 1-month combined ET program could reverse such impairments, so that after the intervention, BC+Ex and CG showing similar results in the cardiorespiratory test and heart rate variability analysis. In conclusion, data of the current study indicate that 1 month of ET is able to reverse impaired cardiorespiratory fitness and autonomic modulation in women with breast cancer receiving adjuvant therapy.

Cardiovascular Response of an Acute Exergame Session in Prepubertal Obese Children.

PURPOSE: We aimed to analyze the acute autonomic response of obese and eutrophic prepubertal boys to an exergame (EXG) session. MATERIALS AND METHOD: Nine eutrophic (8.89 ± 2.71 years of age and 16.42% ± 6.30% body fat) and nine obese boys (8.70 ± 1.16 years of age and 40.76% ± 4.2% body fat) participated. Nutritional state was determined using World Health Organization guidelines. Variables were collected at rest, immediately post (IP), and 60 minutes after a 20 minutes EXG session. Autonomic nervous system (ANS) activity was assessed using heart rate variability in time and frequency domains, and data were analyzed using Shapiro-Wilk and ANOVA tests with Tukey post hoc. RESULTS: The obese group demonstrated an increased sympathetic activity at rest when compared with the eutrophic group (P < 0.05). The obese group also demonstrated an increased parasympathetic activity 60 minutes after the EXG session when compared with the eutrophic group (P < 0.05). CONCLUSION: We concluded that an acute session of EXG promoted ANS super compensation. We encourage research on chronic ANS response to EXG.