Strength Training Session Induces Important Changes on Physiological, Immunological, and Inflammatory Biomarkers.

Strength exercise is a strategy applied in sports and physical training processes. It may induce skeletal muscle hypertrophy. The hypertrophy is dependent on the eccentric muscle actions and on the inflammatory response. Here, we evaluate the physiological, immunological, and inflammatory responses induced by a session of strength training with a focus on predominance of the eccentric muscle actions. Twenty volunteers were separated into two groups: the untrained group (UTG) and the trained group (TG). Both groups hold 4 sets of leg press, knee extensor, and leg curl at 65% of personal one-repetition maximum (1RM), 90 s of recovery, and 2″conc/3″eccen of duration of execution in each repetition. Blood samples were collected immediately before and after, 2 hours after, and 24 h after the end of the exercise session. The single session of strength training elevated the heart rate (HR), rating of perceived exertion (RPE), visual analog scale (VAS), and lactate blood level in UTG and TG. Creatine kinase (CK) levels were higher at 2 and 24 h after the end of the exercise in UTG and, in TG, only at 24 h. The number of white blood cells (WBC) and neutrophils increased in UTG and TG, post and 2 h after exercise. Lymphocytes increased postexercise but reduced 2 h after exercise in both groups, while the number of monocytes increased only immediately after the exercise session in UTG and TG. The strength training session elevated the levels of apelin and fatty acid-binding proteins-3 (FABP3) in both groups and brain-derived neurotrophic factor (BDNF) in TG. The single exercise session was capable of inducing elevated HR, RPE, lactate level, and CK levels. This protocol changed the count/total number of circulating immune cells in both groups (UTG and TG) and also increased the level of plasmatic apelin, BDNF, and FLTS1 only in TG and FABP3 myokines in both groups.

Efeitos cognitivos do teste de esforço progressivo em eletricistas com equipamentos de proteção individual / Cognitive effects of the progressive exercise test in electricians wearing personal protective equipment

Resumo Objetivo: verificar o efeito do esforço físico sobre as funções cognitivas de trabalhadores eletricistas utilizando equipamento de proteção individual (EPI). Métodos: participaram 28 eletricistas que trabalhavam na construção, manutenção e operação de redes de distribuição de energia. Todos do sexo masculino, sadios e aptos para a prática de exercícios físicos. As funções cognitivas foram representadas pelo teste de reação simples (TRS) e pelo nível de vigilância mental (NVM). O TRS e o NVM foram mensurados pré e pós-teste máximo progressivo, em esteira rolante, a 27 °C de temperatura seca e umidade relativa do ar de 64%. O teste consistiu em aumentos progressivos na velocidade e na inclinação da esteira até a fadiga, com utilização de EPI. Resultados: a média (desvio padrão) do TRS não foi significativamente diferente antes, 227,8 (35,1) ms, e após o exercício, 220,6 (24,6) ms. O NVM foi significativamente maior após o exercício em todas as situações: frequência crescente - 36,5 (5,1) Hz vs 39,5 (2,7) Hz, frequência decrescente - 36,0 (5,2) vs 39,0 (3,88) Hz, e frequência geral - 36,2 (4,9) vs 39,2 (3,1) Hz. Conclusão: o exercício progressivo máximo realizado com EPI não modificou o tempo de reação simples e aumentou o nível de vigilância mental de eletricistas.

Abstract Objective: to verify the effects of physical effort on the cognitive functions of electricians wearing personal protective equipment (PPE). Methods: 28 electricians participated. They worked on the construction, maintenance and operation of electrical power distribution networks. All were male, healthy and able to practice physical exercises. The cognitive functions were checked by measuring simple reaction time (SRT) and mental alertness level (MAL). SRT and MAL were measured before and after progressive maximal exercise, on a treadmill, at 27 °C dry temperature and 64% relative humidity, wearing PPE. The test consisted of progressive increases in treadmill speed and incline, until fatigue. Results: SRT mean difference was not significantly different before - 227.8 (35.1) ms - and after exercising -220.6 (24.6) ms. MAL was significantly higher after exercise in all situations: increasing frequency - 36.5 (5.1) Hz vs. 39.5 (2.7) Hz; decreasing frequency-36.0 (5.2) Hz vs. 39.0 (3.88) Hz; and general frequency 36.2 (4.9) Hz vs. 39.2 (3.1) Hz. Conclusion: progressive maximal exercise performed while wearing PPE caused no change in simple reaction time, and increased electricians' mental alertness level.