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This study investigated the effects of concurrent training performed either with repetitions to failure or not to failure in muscle power, muscle quality (MQ), peak oxygen uptake (VO 2peak ), and visceral fat in older men. This is an ancillary analysis of a randomized controlled trial. 36 older men (mean age ± SD; 67.1 ± 5.1 years) were randomized into three groups: one performing repetitions to failure (RFG, n = 13), another performing repetitions not to failure and 50% of the repetitions of the RFG (NFG, n = 12), and third performing repetitions not to failure with equal training volume of the RFG (ENFG, n = 11). The training was performed twice a week for 20 weeks at intensities ranging from 65 to 80% of maximal strength. In each session, the individuals started with strengthening exercises and then performed aerobic exercise (i.e., walking) on a treadmill. The primary endpoint was change from baseline to post-20 wk of absolute and relative muscle power output during squat and countermovement jump, ultrasound measurements for MQ using quadriceps echo intensity, and visceral fat thickness, as well as their VO 2peak through a maximal incremental test on a treadmill. All training groups improved similarly and significantly jump height (ranging from 9 to 16%) and all their muscle power outcomes (mean change ranging from 2 to 7%) (P < .001). In addition, all groups significantly decreased visceral fat thickness (ranging from -11 to -21%) (P < .001), and significantly increased VO 2peak (ranging from 4 to 8%) (P < .01), with no differences between groups. No changes were observed in the MQ outcomes. Concurrent training performed using repetitions to failure or not to failure promoted similar gains in the muscle power output, aerobic capacity, and visceral fat in healthy older men., Competing Interests: Declaration of competing interest The authors have no conflict of interest in relation to the present scientific paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Introduction: Important components that might mediate the relationship between aging and falls are reduced muscle strength and mass. Although muscle-related phenotypes have been linked to falls in older people, the role of muscle quality has yet to be examined., Aim: To investigate the relationship between muscle quality and incidence of falls over an 18-month follow-up in older community-dwelling women., Methods: A total of 167 women (68.1 ± 6.2 years) underwent quadriceps isometric peak torque and thigh-muscle thickness assessments using isokinetic dynamometer and ultrasound, respectively. Muscle quality was considered as the ratio between maximal strength and muscle thickness. Participants were tracked by phone calls for ascertainment of falls during the follow-up period. Cox proportional regressions and X 2 tests were performed, with statistical significance set at P < 0.05., Results: A total of 139 volunteers were successful tracked over the follow-up period. The overall incidence of fall was 23.4% (95% CI: 16.5-31.0). Rate of fallers among individuals with low-muscle quality (57.7%) was higher than in those with normal muscle quality (15.3%) (X 2  = 21.132; P < 0.001). The proportion of multiple fallers was also significantly higher (X 2  = 11.029; P < 0.001) among volunteers with low-muscle quality when compared to those with normal muscle quality (14.8% and 3.6%, respectively). The presence of low-muscle quality was associated with a significantly greater risk of falls over the follow-up (hazard ratio: 4.619; 95% CI: 2.302-9.269)., Conclusion: Low-muscle quality is associated with a higher incidence of falls in older women. These findings provide support for the concept that muscle quality is a clinically meaningful assessment among older people., (Copyright © 2018 Elsevier Inc. All rights reserved.)

This randomized clinical trial compared the neuromuscular adaptations induced by concurrent training (CT) performed with repetitions to concentric failure and not to failure in elderly men. Fifty-two individuals (66.2 ± 5.2 years) completed the pre- and post-measurements and were divided into three groups: repetitions to failure (RFG, n = 17); repetitions not to failure (NFG, n = 20); and repetitions not to failure with total volume equalized to RFG (ENFG, n = 15). Participants were assessed in isometric knee extension peak torque (PT iso ), maximal strength (1RM) in the leg press (LP) and knee extension (KE) exercises, quadriceps femoris muscle thickness (QF MT), specific tension, rate of torque development (RTD) at 50, 100 and 250 ms, countermovement jump (CMJ) and squat jump (SJ) performance, as well as maximal neuromuscular activity (EMG max ) of the vastus lateralis (VL) and rectus femoris (RF) muscles. CT was performed over 12 weeks, twice weekly. Along with each specific strength training program, each group also underwent an endurance training in the same session. After training, all groups improved similarly and significantly in LP and KE 1RM, PT iso , CMJ and SJ performance, RTD variables, specific tension, and VL EMG max , (P < 0.05-0.001). QF MT improved only in RFG and ENFG (P < 0.01). These results suggest that repetitions until concentric failure does not provide further neuromuscular performance gains and muscle hypertrophy, and that even a low number of repetitions relative to the maximal possible (i.e., 50%) optimizes neuromuscular performance in elderly men. Moreover, training volume appears to be more important for muscle hypertrophy than training using maximal repetitions., (Copyright © 2018 Elsevier Inc. All rights reserved.)

This study compared the effects of different weekly training frequencies on the cardiovascular and neuromuscular adaptations induced by concurrent training in previously trained elderly. After 20weeks of combined strength and endurance training, twenty-four healthy elderly men (65±4 years) were randomly placed into two frequency training groups: strength and endurance training performed twice a week (SE2, n=12); or, strength and endurance training performed three times per week (SE3, n=12). The interventions lasted 10 weeks and each group performed identical exercise intensity and volume per session. Before and after the exercise training, one maximum repetition test (1RM), isometric peak torque (PT), maximal surface electromyographic activity (EMG), as well as muscle thickness (MT) were examined. Additionally, peak oxygen uptake (VO(2peak)), maximum aerobic workload (W(max)), first and second ventilatory thresholds (VT1 and VT2) were evaluated. There were significant increases in upper and lower-body 1RM, MT, VO(2peak), VT1 and VT2, with no differences between groups. There were no changes after training in maximal EMG and isometric peak torque. W(max) was improved only in SE3. After 10 weeks of training, twice weekly combined strength and endurance training leads to similar neuromuscular and cardiovascular adaptations as three times per week, demonstrating the efficiency of lower frequency of concurrent training in previously trained elderly men., (© 2013.)

The aim of this study was to compare the effects of low- and high-volume strength training on strength, muscle activation and muscle thickness (MT) of the lower- and upper-body, and on muscle quality (MQ) of the lower-body in older women. Twenty apparently healthy elderly women were randomly assigned into two groups: low-volume (LV, n=11) and high-volume (HV, n=9). The LV group performed one-set of each exercise, while the HV group performed three-sets of each exercise, twice weekly for 13 weeks. MQ was measured by echo intensity obtained by ultrasonography (MQEI), strength per unit of muscle mass (MQST), and strength per unit of muscle mass adjusted with an allometric scale (MQAS). Following training, there was a significant increase (p≤0.001) in knee extension 1-RM (31.8±20.5% for LV and 38.3±7.3% for HV) and in elbow flexion 1-RM (25.1±9.5% for LV and 26.6±8.9% for HV) and in isometric maximal strength of the lower-body (p≤0.05) and upper-body (p≤0.001), with no difference between groups. The maximal electromyographic activation for both groups increased significantly (p≤0.05) in the vastus medialis and biceps brachii, with no difference between groups. All MT measurements of the lower- and upper-body increased similarly in both groups (p≤0.001). Similar improvements were also observed in MQEI (p≤0.01), MQST, and MQAS (p≤0.001) for both groups. These results demonstrate that low- and high-volume strength training promote similar increases in neuromuscular adaptations of the lower- and upper-body, and in MQ of the lower-body in elderly women., (Copyright © 2013 Elsevier Inc. All rights reserved.)

The purpose of the present study was to investigate the relationship between echo intensity, neuromuscular and cardiorespiratory performances in the elderly. Thirty-one healthy elderly men (65.5±5.0) participated in this study. Echo intensity of rectus femoris and quadriceps femoris muscle thicknesses was determined by ultrasound images. Lower-body isometric and isokinetic peak torques (60, 180 and 360°(.s-1)), as well as rate of force development were evaluated as strength parameters. In addition, torque per unit of muscle mass was evaluated by the quotient between isometric peak torque of the knee extensors and the quadriceps femoris muscle thickness. The peak oxygen uptake (VO(2peak)), maximum aerobic workload (W(máx)), absolute (VT(1) and VT(2)) ventilatory thresholds, as well as workloads at VT(1) and VT(2) (W(VT1) and W(VT2)) were evaluated during a maximal incremental test on a cycle ergometer. There were significant negative correlations between the individual values of echo intensity with the corresponding individual values of isometric and isokinetic peak torques (60, 180 and 360°(.s-1)) (r=-0.48 to r=-0.64; P<0.05), as well as with W(VT1) (r=-0.46) and W(VT2) (r=-0.50) (P<0.05). In addition, significant positive correlations were observed between torque per unit of muscle mass and cardiovascular parameters (r=0.52 to r=0.60; P<0.001). The present results suggest that the echo intensity analysis using computer-aided gray-scale analysis is a low cost, easily accessible, and a safe method to evaluate the muscle quality, and may contribute to the research of neuromuscular and cardiovascular performances in the elderly., (Copyright © 2012 Elsevier Inc. All rights reserved.)

This study investigated the effects of different intra-session exercise sequences in the cardiovascular and neuromuscular adaptations induced by concurrent training in elderly. Twenty-six healthy elderly men (64.7±4.1years), were randomly placed into two concurrent training groups: strength training prior to (SE, n=13) or after (ES, n=13) endurance training. Subjects trained strength and endurance training 3 times per week performing both exercise types in the same training session. The peak oxygen uptake (VO(2peak)), maximum aerobic workload (W(máx)), absolute (VT(1) and VT(2)) and relative (VT(1)% and VT(2)%) ventilatory thresholds, as well as workloads at VT(1) and VT(2) (W(VT1) and W(VT2)) were evaluated during a maximal incremental test on a cycle ergometer before and after the training. In addition, muscle quality (MQ) was evaluated by the quotient between maximal dynamic strength (one repetition maximum test) of the knee extensors and the quadriceps femoris muscle thickness determined by ultrasonography. There were no modifications after training in the VT(1), VT(2), VT(1)%, and VT(2)%. There was significant increase in the W(VT1) only in SE (P<0.05), as well as significant increase in the W(VT2) in both groups (P<0.001). There was significant increase in the VO(2peak), with both groups showing increases (P<0.001), with no difference between groups; as well significant increase in the W(máx) (P<0.001) with no difference between SE and ES. The force per unit of muscle mass of knee extensors increased in both groups (P<0.001), but the increase was significantly higher in SE than in ES (27.5±12.7 vs. 15.2±10.3%, P<0.02). Hence, the intra-session exercise sequence had no influence in the maximal endurance power adaptations to concurrent training, but had influence in the magnitude of the muscle quality enhancements., (Copyright © 2011 Elsevier Inc. All rights reserved.)