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SummaryBackground: Due to the existing controversies in literature about the potential benefits of resistance exercise training (RT) on arterial blood pressure (BP) at rest, and the lack of studies conducted with elderly hypertensive individuals, RT is seldom recommended as a non-pharmacological treatment for arterial hypertension.

This study examined the association between ACE I/D and ACTN3 R577X polymorphisms and muscle-related phenotypes and their adaptation to resistance training in older women. Volunteers (n=246;age=66.7 ± 5.5 years) underwent quadriceps strength assessment using isokinetics and fat-free mass by dual energy X-ray absorptiometry. 79 volunteers performed 24 weeks of resistance training and 75 were studied as controls. Genotypes were identified by standard procedures. No associations were observed for muscle strength for either gene, but volunteers carrying the D/D genotype presented higher appendicular fat-free mass compared to the I-allele carriers (6.3 ± 0.1 vs. 6.1 ± 0.1 kg/m (2)). The X-allele carriers presented higher relative fat-free mass when compared to homozygous R/R (16.3 ± 0.1 vs. 15.9 ± 0.1 kg/m (2)). All fat-free mass variables were significantly greater for carriers of both X/X and D/D genotypes. In response to RT, only the I-allele carriers significantly increased fat-free mass and a significant training × genotype interaction was noted. These findings do not support a pivotal role for the studied polymorphisms in determining muscle strength in older women, but suggest a modest role in fat-free mass determination. Of note, the results provide a novel insight that these genetic variations may interact to determine muscle mass in older women.

This study examined the effects of resistance training (RT) on knee extensor peak torque (KEPT) and fat-free mass (FFM) in older women. Seventy-eight volunteers (67.1 ± 5.9 years old) underwent 24 weeks of progressive RT (RTG) while 76 (67.4 ± 5.9 years old) were studied as controls (CG). Dominant knee extension peak torque was assessed using an isokinetic dynamometer (Biodex System 3) and FFM measurements were performed by dual-energy x-ray absorptiometry. Muscle strength and FFM were evaluated before and after the intervention in all volunteers. Participants in the RTG trained major muscle groups 3 times per week during 24 weeks. Training load was kept at 60% of 1 repetition maximum in the first 4 weeks, 70% in the following 4 weeks, and 80% in the remaining 16 weeks, with repetitions, respectively, decreasing from 12, 10, and 8. A Split-plot analysis of variance was performed to examine between- and within-group differences, and the level of significance was accepted at p ≤ 0.05. It was observed that the RTG showed significant increases in KEPT (from 89.9 ± 21.8 to 102.8 ± 22.6 N·m; p < 0.05) and FFM (from 36.4 ± 4.0 to 37.1 ± 4.2 kg, p < 0.05). Appendicular FFM was also significantly increased after the intervention period in the RTG (13.9 ± 1.8 to 14.2 ± 1.9 kg, p < 0.05). None of these changes were observed for the CG. Consistent with the literature, it is concluded that a progressive RT program promotes not only increases in muscle strength, as evaluated by an isokinetic dynamometer, but also in FFM as evaluated by the DXA, in elderly women.

The aim of this study was to investigate the acute effect of resistance exercise performed at different intensities on the hemodynamics of normotensive men. The study included 10 normotensive and recreationally-trained men (25.40 ± 6.90 years) performed the following three experimental protocols in a randomized order: a) 60% of 8RM; b) 80% of 8RM; c) 100% of 8RM. All protocols performed six exercises (Leg Press, Vertical Bench Press, Leg Flexion, Close-Grip Seated Row, Leg Extension and Shoulder Press) with three sets of eight repetitions for each exercise. Systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR) and double product (DP) were measured at rest, at the end of exercise and during the 60-minute post-exercise. The findings showed that there was a significant reduction in the faster SBP with a longer duration (p< 0.0001) for the 100% of 8RM intensity, but without significant decreases in DBP for all intensities (p> 0.05). There were significantly higher elevations in HR and DP for 100% of 8RM at all times (p<0.0001). We conclude that high intensities (100% of 8RM) promote post-exercise hypotension with faster responses and greater duration and increase HR and DP in normotensive men.Keywords: post-exercise hypotension, blood pressure, double product, heart rate RESUMO O objetivo do presente estudo foi verificar o efeito agudo do exercício de força realizado em diferentes intensidades sobre a hemodinâmica de homens normotensos. Participaram do estudo 10 homens aparentemente saudáveis (25.40 ± 6.90) divididos aleatoriamente em três protocolos experimentais: a) 60% de 8RM; b) 80% de 8RM; c) 100% de 8RM. Todos os protocolos realizaram seis exercícios (leg press 45°, supino vertical, flexão de joelhos, remada sentada fechada, extensão de joelhos e desenvolvimento na máquina), com três series de oito repetições para cada exercício. A pressão arterial sistólica (PAS), diastólica (PAD), freqüência cardíaca (FC) e o duplo produto (DP) foram mensurados em repouso, no final dos exercícios e durante os 60 minutos pós-exercício. Os resultados mostram que houve redução significativa na PAS mais rápida com maior duração (p< 0.05) para intensidade 100% de 8RM, porém sem reduções significativas na PAD para todas as intensidades (p> 0.05). Houve maiores elevações significativas na FC e no DP para 100% de 8RM em todos os momentos (p> 0.05). Conclui-se que altas intensidades (100% de 8RM) promovem hipotensão pós-exercício com respostas mais rápidas e de maior duração e eleva a FC e o DP de homens normotensos.Palavras-Chave: hipotensão pós-exercício, pressão arterial, duplo produto, frequência cardíaca Manuscript