Effect of whole-body resistance training at different load intensities on circulating inflammatory biomarkers, body fat, muscular strength, and physical performance in postmenopausal women.

The primary purpose of this study was to identify the impact of whole-body resistance training (RT) at different load intensities on adipokines, adhesion molecules, and extracellular heat shock proteins in postmenopausal women. As secondary purpose, we analyzed the impact of RT at different load intensities on body fat, muscular strength, and physical performance. Forty participants were randomized into lower-load intensity RT (LIRT, n = 20, 30-35 repetition maximum in the first set of each exercise) or higher-load intensity RT (HIRT, n = 20, 8-12 repetition maximum in the first set of each exercise). Adipokines (adiponectin and leptin), adhesion molecules (MCP-1 and ICAM-1), extracellular heat shock proteins (HO-1 and eHSP60), body fat, muscular strength (1RM), and physical performance [400-meter walking test (400-M) and 6-minute walking test (6MWT)] were analyzed at baseline and after 12-weeks RT. There was a significant time-by-group interaction for eHSP60 (P = 0.049) and 400-M (P = 0.003), indicating superiority of HIRT (d = 0.47 and 0.55). However, both groups similarly improved adiponectin, ICAM-1, HO-1, body fat, 1RM, and 6MWT (P < 0.05). Our study suggests that load intensity does not seem to determine the RT effect on several obesity-related pro-inflammatory and chemotactic compounds, body fat, 1RM, and 6MWT in postmenopausal women, although a greater improvement has been revealed for eHSP60 and 400-M in HIRT. Novelty: Higher-load intensity resistance training improves eHSP60 and 400-M in postmenopausal women. Resistance training improves the inflammatory profile, body fat, muscle strength, and 6MWT, regardless of load intensity.

Atividade física no lazer como critério discriminante do menor nível de estresse percebido em adolescentes / Leisure-time physical activity as discriminant criterion of low level perceived stress in adolescents

O objetivo do presente estudo foi identificar os pontos de corte do tempo de realização de atividades físicas no lazer (AFL) de diferentes intensidades como critério discriminante do menor nível de estresse percebido (MEP) em adolescentes. Trata-se de um estudo transversal com amostra composta por adolescentes de 14 a 18 anos, de ambos os sexos, do ensino médio regular. Dados da atividade física e do MEP foram obtidos por meio de autorrelato, utilizando-se o questionário COMPAC. O MEP (respostas: "raramente" + "às vezes") foi considerado variável de classificação, enquanto minutos em AFL de intensidade moderada (AFLM), vigorosa (AFLV) e moderada a vigorosa (AFLMV) as variáveis de teste. Na análise dos dados foi usada a curva ROC, complementadas por valores de sensibilidade (SE) e especificidade (ES), adotando-se área sob a curva (AUC) > 0,50 e fixando-se p < 0,05. A amostra final deste estudo foi de 984 adolescentes (idade: homens = 15,93 ± 1,10 anos; moças = 15,87 ± 1,04 anos) com maior participação de moças (55,3%). O tempo de realização de AFLM ≥ 40 min/sem (AUC = 0,59; SE = 41,7%; ES = 75,7%; p < 0,002) e AFLMV ≥ 80 min/sem (AUC = 0,58; SE = 83,2%; ES = 36,2%; p < 0,04) para os rapazes apresentou poder discriminante para MEP. Neste estudo transversal, os minutos de realização de AFLM e AFLMV foram discriminantes do MEP para os rapazes. As AUC, para ambas as intensidades de AFL, foram baixas e com desequilíbrio entre valores de SE e ES. É sugerido que outros delineamentos de pesquisa sejam empregados a fim de estabelecer a relação causa e efeito entre a prática de AFL de diferentes intensidades e os níveis de estresse em adolescentes...(AU)

The aim of this study was to identify the cutoffs of the leisure-time physical activity (LPA), at different intensities, as discriminant criterion of lowest level of perceived stress (LLPS) in adolescents (14-18 years). This is a population-based, cross-sectional study, including regular high school students. PA and LLPS data was self-reported through questionnaire COMPAC. The classification variable was the LLPS (rarely + sometimes). The test variables were the minutes of LPAL of moderate intensity (LPAM) and vigorous (LPAV) and moderate to vigorous (LPAMV). The cutoffs were analyzed by ROC curves, complemented by sensitivity (SE) and specificity (ES) values, adopting area under the curve (AUC > 0.50; p < 0.05). The final sample of 984 adolescents (boys = 15.93 ± 1.10 years; girls = 15.87 ± 1.04 years) with a higher proportion of girls (55.3%). The time spent in LPAM ≥ 40 min/week (SE = 41.7%, ES = 75.7% AUC = 0.59; p < 0.002) and LPAMV ≥ 80 min/week (SE = 83.2%; ES = 36.2%; AUC = 0.58; p < 0.04) for the boys presented discriminant power to LLPS. In this cross-sectional study, LPAM and LPAMV minutes showed discriminatory power for LLPS in male. However, the AUCs for both LPA intensities were low and with imbalance between SE and ES values. Other research designs should be used to establish the cause-effect relationship between PAL and stress levels in adolescents...(AU)