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Resistance training in older women: Comparison of single vs. multiple sets on muscle strength and body composition
Abstract
BACKGROUND: Studies are conflicting as to whether single-set resistance training (RT) are as effective as multi-set protocols with respect to promoting muscular adaptations. Several meta-analyses have shown that a clear dose-response relationship exists between RT volume and muscular adaptations. However, a majority of studies were not specific to older individuals, particularly women. OBJECTIVE: To determine changes in strength and body composition in elderly women following 1 vs. 3 sets of RT. METHODS: Thirty older women participated in a 12-week supervised total body RT program. Participants were randomly assigned to perform either 1 set (G1S) or 3 sets (G3S) per session. All other RT variables were held constant. Body composition was assessed by dual X-ray absorptiometry, muscle strength was evaluated by 1RM in chest press and knee extension. RESULTS: Increases in strength were significantly (p < 0.05) greater in G3S versus G1S in both the chest press (+26.6%, versus +20.3%) and the knee extension (+23.9% versus +16.2%). No significant (p > 0.05) differences were noted in body composition components between groups. CONCLUSIONS: Findings indicate that multiple set protocols are required to optimize strength gains in older women. Changes in body composition appear to be similar irrespective of training volume during the initial stages of RT.
... Most experimental studies that analyzed the effects of RT volume on muscle and functional adaptations in middle-aged or older adults focused on comparing single versus multiple sets per exercise, maintaining most training variables equal between groups (e.g., duration, frequency, repetitions, intensity, and exercise selection and order) and generally observed contradictory findings. For example, a few studies reported significantly higher lower-limb strength gains after multiple sets than single sets (e.g., 26-52% vs 17-37%, respectively) [36,37], while most failed to observe differences between the number of sets (e.g., 4-54% vs 0.2-65%, respectively) [38][39][40][41][42][43][44][45][46][47]. In addition, most studies did not observe differences between single versus multiple sets for muscle size (e.g., 1-28% vs 2-29%, respectively) or muscle quality (e.g., 11-19% vs 15-22%, respectively) [38,39,[41][42][43][44][45][48][49][50], as well as for functional capacity (e.g., 2-11% vs 3-16%, respectively) [38,40,45]. ...
... For muscle strength, all studies (eight) presented an overall rating of a serious risk of bias [36-40, 42, 44, 45]. For muscle size, two studies had an overall rating of a moderate risk of bias [37,42], and five had a serious risk of bias [36,38,39,44,45]. For muscle quality, all studies (two) presented an overall rating of a serious risk of bias [39,44]. ...
... MD = 9.53 kg; 95% CI 7.19-11.87). Of the 12 studies that compared the effects of single versus multiple sets on lower-limb strength, two found significant differences between groups at post-test with a greater effect of multiple than single sets [36,37] (Table S1 in the Electronic Supplementary Material [ESM]). Combined SMD and MD showed a greater effect of multiple than single sets on lower-limb strength gains, without evidence of heterogeneity (Table 5, Fig. S1 in the ESM). ...
Background
Effective manipulation of the acute variables of resistance training is critical to optimizing muscle and functional adaptations in middle-aged and older adults. However, the ideal volume prescription (e.g., number of sets performed per exercise) in middle-aged and older adults remains inconclusive in the literature.
Objective
The effects of single versus multiple sets per exercise on muscle strength and size, muscle quality, and functional capacity in middle-aged and older adults were compared. Moreover, the effects of single versus multiple sets per exercise on muscular and functional gains were also examined, considering the influence of training duration.
Methods
Randomized controlled trials and non-randomized controlled trials comparing single versus multiple sets per exercise on muscle strength, muscle size, muscle quality, or functional capacity in middle-aged and older adults (aged ≥ 50 years) in the PubMed/MEDLINE, Web of Science, and Scopus databases (01/09/2021, updated on 15/05/2022) were identified. A random-effects meta-analysis was used.
Results
Fifteen studies were included (430 participants; 93% women; age 57.9–70.1 years). Multiple sets per exercise produced a greater effect than single sets on lower-limb strength (standardized mean difference [SMD] = 0.29; 95% confidence interval [CI] 0.07–0.51; mean difference [MD] = 1.91 kg; 95% CI 0.50–3.33) and muscle quality (SMD = 0.40; 95% CI 0.05–0.75) gains. There were no differences between single versus multiple sets per exercise for upper-limb strength (SMD = 0.13; 95% CI − 0.14 to 0.40; MD = 0.11 kg; 95% CI − 0.52 to 0.75), muscle size (SMD = 0.15; 95% CI − 0.07 to 0.37), and functional capacity (SMD = 0.01; 95% CI − 0.47 to 0.50) gains. In addition, there were no differences between single versus multiple sets on muscle strength and size gains for training durations ≤ 12 weeks or > 12 weeks.
Conclusions
Multiple sets per exercise produced greater lower-limb strength and muscle quality gains than single sets in middle-aged and older adults, although the magnitude of the difference was small. In contrast, single sets per exercise were sufficient to improve upper-limb strength, muscle size, and functional capacity in these populations. Despite these findings, researchers should conduct future high-quality, pre-registered, and blinded randomized controlled trials to strengthen the scientific evidence on this topic.
... the highest volume group obtained higher increases in elbow extensors hypertrophy in comparison with the 6-and 18-set groups, but no difference was reported between 6 and 18 sets. ribeiro et al. [41] found similar effects on lean body mass when comparing 3 vs. 9 weekly sets per muscle group in elderly women. the participants performed supervised full-body routine with 8 exercises done in the following order: chest press, horizontal leg press, seated row, knee extension, preacher curl, leg curl, triceps pushdown, and seated calf raise. ...
... In addition, the values of rPE indicate that the intensity of effort was increased during the study and near-maximum efforts were achieved at the end. While 1 study performed sets at non-repetition maximum [36], 6 involved sets at repetition maximum [31,33,38,39,41,42] and 5 applied sets at muscle failure [30,34,35,40,43] in accordance with the previous definition [24]. considering that in the study by sooneste et al. [37], the participants performed sets until momentary failure or until achieving 10 repetitions, is not clear if both groups were able to obtain similar intensity of effort during sets since is not defined how much effort represented 10 repetitions to the participants. ...
... regarding hypertrophy and body composition measures, 6 studies assessed muscle thickness by ultrasound [30,34,[38][39][40]42], 4 evaluated muscle crosssectional area by magnetic resonance imaging [33,[35][36][37], 3 established lean body mass by dual energy X-ray absorptiometry [31,32,41] and 1 by bioimpedance [43]. ...
Purpose. To conduct a narrative review of relevant studies comparing the impact of different resistance training (RT) volumes
on muscle hypertrophy and lean body mass.
Methods. Studies were eligible for inclusion if they were clinical trials comparing the effects of different RT volumes on
muscle hypertrophy and body composition. Overall, 22 articles were considered relevant and included in this review after an
extensive literature hand search of the following databases: SciELO, PubMed/MEDLINE, Scopus, SPORTDiscus, LILACS,
and Web of Science.
Results. Of the 22 studies, 6 showed greater effects of high-volume, 1 showed greater effects of low-volume, and the remaining
studies showed no difference between high- and low-volume RT. Five studies that revealed better results for higher volume were
performed in untrained people, 1 concerned trained people, and the study that presented better results for lower volume
referred to trained subjects. High heterogeneity was observed in the studies’ methodology regarding training protocols,
population characteristics, length of intervention, supervision status, and measures of muscle size and body composition.
Conclusions. Our findings suggest that muscle size and lean body mass are not mainly affected by RT volume and that
other variables, especially the intensity of effort, should be considered in RT prescription. In this sense, increased volume
could be beneficial, especially when training with low effort or when effort is not well controlled. However, it is important
to note that there seems to be a ceiling effect and the use of higher volumes might be detrimental to muscle hypertrophy over
a long term.
... In this regard, resistance training (RT) programs have been widely supported as a major countermeasure to the age-related declines mentioned above (3)(4)(5)(6)8,9,12,14,17,18,20,(24)(25)(26)(27)(28)30,34,36,39,40,(42)(43)(44). During the past several decades, some organizations have released recommendations concerning RT programs to provide a framework for training prescription guidelines for individuals of different trainability status, especially for older adults (3,4,20,24). ...
... The present study is part of a longitudinal research project named "Active Aging Longitudinal Study," initiated in 2012, whose purpose is to analyze the effects of supervised, structured, and progressive RT program on neuromuscular, morphological, physiological, and metabolic outcomes in older women (37,39). This investigation was carried out over a total of 46 weeks, with 2 weeks for familiarization sessions to the exercises (weeks 1 and 2), 2 weeks dedicated to pretraining measurements (weeks 3 and 4), 12 weeks to training phase (weeks 5-16), 2 weeks for posttraining measurements (weeks 17 and 18), 12 weeks dedicated to detraining (weeks 19-30), 2 weeks for measurements of detraining effects (weeks 31 and 32), 12 weeks dedicated to retraining (weeks [33][34][35][36][37][38][39][40][41][42][43][44], and 2 final weeks for the measurement of retraining effects (weeks 45 and 46). Measures related to anthropometry, muscular strength, body composition, and metabolic blood biomarkers were recorded throughout. ...
... A possible reason for subjects in that study having returned to baseline values (45) and our subjects have not might be explained by the higher volume of the RT program in the previous study (3 sets for each of the 6 exercises) compared with the current investigation (singleset for each exercise). Work in our laboratory (42) and other investigators (6,23) have shown that multiple sets can produce higher increases in muscular strength than a single-set program in older women, although this remains controversial (14). Also, Hvid et al. (28) observed significant reductions (226%, p , 0.05) in muscular strength in the lower body of older men after short-term disuse (immobilization for 2 weeks), with subsequent increases of 25% Detraining and Retraining in Older Women (2020) 00:00 | www.nsca.com ...
The main purpose of this study was to assess the effects of resistance training (RT) frequency following a retraining period on muscular strength, body composition, and metabolic biomarkers after a detraining period in older women. Fourty older women ( 60 yrs) were randomly assigned to two groups that perform RT two or three times per week during 12 weeks. They were then detrained for 12 weeks, and after that, retrained for more 12 weeks in the same groups of training frenquency. RT protocol was composed of 8 exercises, which were performed in 1 set of 10-15 repetition maximum. Muscular strength was assessed by 1RM tests in chest press and leg extension exercises. Body composition was estimated by DXA. Following the detraining period, there were observed decreases (P < 0.05) in fat-free mass (FFM), and increases in fat mass (FM) and relative body fat (%fat). Upper- and lower-body muscular strength decreased with detraining (P < 0.05), resulting in a worsening in muscle quality. Fasting glucose, LDL-C, and triglycerides increased by 6-27% (P < 0.05), while testosterone decreased by 24-28% (P < 0.05). Following retraining, both groups regained muscular strength and FFM and, consequently, improved muscle quality (P < 0.05). In addition, retraining promoted an increase in testosterone, and reduction in FM and %fat (P < 0.05). However, gains were lower than post-training levels for muscular strength, muscle quality and testosterone (P < 0.05). Total cholesterol, HDL-C, IGF-1, and C-reactive protein did not change at any time point of the study for either group (P > 0.05). Our results suggest that older women are able to regain previous RT program benefits following a period of detraining, regardless of the weekly training frequency, although some fitness components may take longer to re-establish than the initial training level.
... Among several possible RT variables to be manipulated, the training volume has been considered as a critical variable to maximize RT-induced hypertrophy. Considering this, many of the studies that compared the direct effect of volumes, that is one set vs. three sets of RT, on muscle hypertrophy in older adults (12,17,32,34) have failed to show a difference in muscle hypertrophy, but not all (10,31). However, higher RT volume (a higher number of sets) leads to higher myofibrillar protein synthesis in older adults (23). ...
... Several studies have used one-set and 3-set routines to compare the direct effect of RT volumes on muscle hypertrophy in older adults. Many of the studies have failed to show a difference in muscle hypertrophy between the routines (12,17,32,34), but not all (10,31). Regarding this, the effect sizes (from pre-intervention to postintervention) of these studies (when analyzed collectively) (10,12,17,31,32,34) have shown a higher effect to HV-RT (d 5 0.8) than LV-RT (d 5 0.5) (the effect size was calculated by the authors of the current study). ...
... Many of the studies have failed to show a difference in muscle hypertrophy between the routines (12,17,32,34), but not all (10,31). Regarding this, the effect sizes (from pre-intervention to postintervention) of these studies (when analyzed collectively) (10,12,17,31,32,34) have shown a higher effect to HV-RT (d 5 0.8) than LV-RT (d 5 0.5) (the effect size was calculated by the authors of the current study). Thus, a low effect size (D d 5 0.3) may be observed between one-set and 3-set routines in muscle hypertrophy. ...
Among several possible resistance training (RT) variables to be manipulated, the training volume has been considered as a critical variable to maximize RT-induced hypertrophy. Many of the studies that compared one set of RT with 3 sets have failed to show a difference in muscle hypertrophy in older adults. However, it is not clear whether further increases in RT volume (i.e., 6 sets) would result in even greater RT-related hypertrophy than 3 sets in older adults. This study aimed to investigate whether higher-volume RT (HV-RT) maximizes gains in lean body mass and muscle strength (MS) when compared with lower-volume RT (LV-RT) in postmenopausal women (PW). Fifty-eight PW were randomized into 1 of the 3 groups: control group (CT, no exercise), HV-RT (6 sets per exercise), and LV-RT (3 sets per exercise). Volunteers took part in a supervised training program (leg press 45°, leg extension, leg curl and standing calf raises) and were assessed for leg lean mass (LLM; dual X-ray absorptiometry) and lower limb MS (leg press and leg extension; 1 repetition maximum [1RM]) before and after 12 weeks of RT. Both HV-RT and LV-RT groups increased (p,0.05) LLM andMS when compared with the CT group. Higher increases in LLM gains were observed for the HV-RT group when compared with the LV-RT group (6.1 and 2.3%, p , 0.001). Both HV-RT and LV-RT groups similarly increased 1RM in the leg press and leg extension. Thus, there seems to be a dose-response relationship between RT volume and muscle hypertrophy, but not for MS gains in PW.
... Some studies have used different dependent variables but also have shown greater response to higher volume (10,21), such as the results found in our study. On the other hand, there are studies that did not observe differences between one versus three sets per exercise for body composition alterations (31,33). Although the reasons for these conflicting results are not clear, they may be related to factors such as differences in training protocols with regard to volumes and/or intensities, in the characteristics of the participants, or even in the variables analyzed. ...
... This study showed larger decreases in glucose in the HV group after intervention compared to the LV group. These results are in line with those found by Ribeiro et al. (33) and Tomeleri et al. (41). In both studies, three sets were performed per exercise, and, as in our study, reductions in blood glucose were found. ...
... The HV group produced over twice as much reduction CPR as did the LV group. This information corroborates works conducted by Ribeiro et al. (33) and Tomeleri et al. (41). One of the possible mechanisms responsible for such reductions is related to vigorous muscle contraction, which in turn produces anti-inflammatory substances that may act as antagonists to CPR, therefore helping to reduce its blood concentrations (29). ...
The purpose of this study was to compare the effects of resistance training (RT) performed with two different volumes on body fat and blood biomarkers in untrained older women. Sixty-five physically independent older women (≥ 60 years) were randomly assigned to one of three groups: low volume training group (LV), high volume training group (HV), and a control group (CG). Both training groups performed RT for 12 weeks, using 8 exercises of 10-15 repetitions maximum (RM) for each exercise. LV performed only a single set per exercise whereas HV performed three sets. Anthropometric, body fat (%), trunk fat, triglycerides (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-c), high density lipoprotein cholesterol (HDL-c), very low-density lipoprotein cholesterol (VLDL-c), glucose (GLU), C-reactive protein (CRP) and composite Z-score were measured. The HV group obtained greater improvements compared to LV (p < 0.05) for TG (LV =-10.5% vs. HV =-16.6%), VLDL-c (LV =-6.5% vs. HV =-14.8%), GLU (LV =-4.7% vs. HV =-11.1%), CRP (LV =-13.2% vs. HV =-30.8%), % body fat (LV =-2.4% vs. HV =-6.1%), and composite Z-score (LV =-0.13 ± 0.30 vs. HV =-0.57 ± 0.29). Trunk fat was reduced (p < 0.05) only in the HV group (-6.8%). We conclude that RT performed in higher volume seems to be the most appropriate strategy to reduce body fat (%), trunk fat, improve blood Powered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporation biomarkers, and reduce composite Z-score in older women.
... Some studies have used different dependent variables but also have shown greater response to higher volume (10,21), such as the results found in our study. On the other hand, there are studies that did not observe differences between 1 vs. 3 sets per exercise for body composition alterations (31,33). Although the reasons for these conflicting results are not clear, they may be related to factors such as differences in training protocols regarding volumes or intensities, in the characteristics of the subjects, or even in the variables analyzed. ...
... This study showed larger decreases in the glucose level in the HV group after intervention compared with the LV group. These results are in line with those found by Ribeiro et al. (33) and Tomeleri et al. (40). In both studies, 3 sets were performed per exercise, and, as in our study, reductions in the blood glucose level were found. ...
... The HV group produced over twice as much reduction CPR as did the LV group. This information corroborates works conducted by Ribeiro et al. (33) and Tomeleri et al. (40). One of the possible mechanisms responsible for such reductions is related to vigorous muscle contraction, which in turn produces anti-inflammatory substances that may act as antagonists to CPR, therefore helping to reduce its blood concentrations (29). ...
The purpose of this study was to compare the effects of resistance training (RT) performed with two different volumes on body fat and blood biomarkers in untrained older women. Sixty-five physically independent older women (≥ 60 years) were randomly assigned to one of three groups: low volume training group (LV), high volume training group (HV), and a control group (CG). Both training groups performed RT for 12 weeks, using 8 exercises of 10-15 repetitions maximum (RM) for each exercise. LV performed only a single set per exercise whereas HV performed three sets. Anthropometric, body fat (%), trunk fat, triglycerides (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-c), high density lipoprotein cholesterol (HDL-c), very low-density lipoprotein cholesterol (VLDL-c), glucose (GLU), C- reactive protein (CRP) and composite Z-score were measured. The HV group obtained greater improvements compared to LV (p < 0.05) for TG (LV = -10.5% vs. HV = -16.6%), VLDL-c (LV = -6.5% vs. HV = -14.8%), GLU (LV = -4.7% vs. HV = -11.1%), CRP (LV = -13.2% vs. HV = -30.8%), % body fat (LV = -2.4% vs. HV = -6.1%), and composite Z-score (LV = -0.13 ± 0.30 vs. HV = -0.57 ± 0.29). Trunk fat was reduced (p < 0.05) only in the HV group (-6.8%). We conclude that RT performed in higher volume seems to be the most appropriate strategy to reduce body fat (%), trunk fat, improve blood biomarkers, and reduce composite Z-score in older women.
... However, although it is suggested that older adults perform RT with multiple sets (MS) rather than with single sets (SS) (1), current evidence on the topic indicates the data are insufficient to draw firm conclusions (3,27,31,35). Studies directly comparing SS and MS have shown conflicting results: Some demonstrate superiority of higher volumes (16,24,29), whereas others show no statistically significant differences between conditions (6,25,26). The crucial point may be the duration of the investigations, where significant differences between SS and MS manifest over longer periods (24). ...
... Universitat Kiel, Kiel, Germany). Data from previous studies from our laboratory, in which RT was the exercise intervention model and effects on muscle mass, MQ, muscular strength were determined, were used for the sample size estimation (10,29,30). We based the calculation on an effect size of 0.30, an a level of 0.05, and a power (1 2 b) of 0.80. ...
... We showed that 12 weeks of RT, regardless of the training volume used, promoted increases in muscular strength, muscle mass and quality, and IGF-1 in a cohort of untrained older women. To our knowledge, this is the first study that compares the effects of single vs. MS on IGF-1 levels and presents the analysis of training load progression throughout the weeks, includes a control group, and is only the second study (29) to evaluate nutritional intake during such an intervention. ...
The purpose of this study was to compare the effects between single-set vs. multiple-sets of resistance training (RT) on measures of muscular strength, muscle mass, muscle quality (MQ) and insulin-like growth factor 1 (IGF-1) in untrained healthy older women. Sixty-two older women were randomly assigned to one of the three groups: single-set RT (SS, n = 21), multiple-sets RT (MS, n = 20), or non-training control (CG, n = 21). Both training groups performed RT for 12 weeks, using 8 exercises of 10-15 repetitions maximum (RM) for each exercise. The SS group performed only 1 set per exercise whereas MS performed 3 sets. Anthropometric, muscle strength (1RM tests), lean soft tissue (LST) and MQ from upper (UL) and lower limbs (LL), and IGF-1 were measured pre- and post-training. Both training groups showed significant pre- to post-training increases for UL1RM (SS: 37.1%, MS: 27.3%, CG: -3.0%), LL1RM (SS: 16.3%, MS: 21.7%, CG: -0.7%), ULLST (SS: 7.8%, MS: 8.8%, CG: -1.1%), LLLST (SS: 5.6%, MS: 6.3%, CG: -0.8%), ULMQ (SS: 25.2%, MS: 16.7%, CG: -0.2%), LLMQ (SS: 10.5%, MS: 15.4%, CG: -3.5%), IGF-1 (SS: +7.1%, MS: +10.1%, CG: -2.2%). We conclude that both SS and MS produce similar increases in muscular strength, LST and MQ of upper and lower limbs, and IGF-1 after 12 weeks of RT in untrained older women. Our results suggest that, in the early stages, the RT regardless number of sets is effective for improving muscular outcomes in this population.
... Thus, based on the numerous benefits reported in literature [5][6][7][8][9] , regular practice of resistance training has been widely recommended, especially for elderly individuals, since it is considered a non-pharmacological intervention strategy that is very attractive in mitigating the deleterious effects related to the aging process [7][8] . Among the main modifications associated with resistance training practice are: muscle strength gains 9 and increased muscle mass 7-8, reduction of body fat [7][8][9] and also improvement in muscle quality 8 . ...
... Thus, based on the numerous benefits reported in literature [5][6][7][8][9] , regular practice of resistance training has been widely recommended, especially for elderly individuals, since it is considered a non-pharmacological intervention strategy that is very attractive in mitigating the deleterious effects related to the aging process [7][8] . Among the main modifications associated with resistance training practice are: muscle strength gains 9 and increased muscle mass 7-8, reduction of body fat [7][8][9] and also improvement in muscle quality 8 . ...
... Thus, based on the numerous benefits reported in literature [5][6][7][8][9] , regular practice of resistance training has been widely recommended, especially for elderly individuals, since it is considered a non-pharmacological intervention strategy that is very attractive in mitigating the deleterious effects related to the aging process [7][8] . Among the main modifications associated with resistance training practice are: muscle strength gains 9 and increased muscle mass 7-8, reduction of body fat [7][8][9] and also improvement in muscle quality 8 . ...
Overweight among older adults has increased considerably, and resistance training (RT) is a very attractive intervention strategy for positive changes associated with its practice. The aim was to evaluate the impact of nutritional status on body composition and muscle strength of older women in a RT program. Forty-eight older women were divided into three groups: eutrophic (EUT, BMI ≤ 24.9 kg/m²), overweight (OVE, BMI between 25.0 and 29.9 kg/m²) and obese (OBE, BMI ≥ 30.0 kg/m2). RT was performed for 12 weeks, one set of 10 to 15 repetitions, eight exercises, three weekly sessions. Body composition assessments (muscle mass, fat mass and trunk fat), strength and muscle quality were performed. Interaction for muscle mass in EUT had significant effect (+ 4.0%) when compared to OVE (+ 1.4%) and OBE (+ 1.4%). Time effect was observed for muscle
strength (EUT = + 10.6%, OVE = + 7.5% and OBE = + 11.0%), muscle quality (EUT = + 6.1%, OVE = + 6.3% and OBE = + 9.8%), trunk fat (EUT = - 3.3%, OVE = - 0.7% and OBE = - 0.7%) and fat mass (EUT = - 3.0%, OVE = - 1.5% and OBE = - 0.5%). The results suggest that RT is effective for improving strength, muscle quality, muscle
mass, trunk fat and fat mass of older women, but nutritional status may be determinant in muscle mass changes.
... The meta-regression study of Borde et al. (2015) (6) compared RT protocols (sets ranging from 1 to 5 sets) an AU3 d observed that 2-3 sets per exercise result in the largest improvement in muscle strength; nevertheless, the author pointed out that there is a paucity of data from highquality randomized clinical trials (RCTs) concerning the effects of RT volume on muscle strength, especially in the elderly. To the best of our knowledge, only 5 studies have investigated the effects of RT volume on muscle strength gains in older adults (1,12,20,46,47). However, no RCT studies investigating the RT volume effects on muscle strength in older people have used more than 3 sets. ...
... However, no RCT studies investigating the RT volume effects on muscle strength in older people have used more than 3 sets. These studies have shown that low-volume RT, even as low as 1 set, increases muscle strength in older people (1,12,20,46,47). However, 3 of these studies have confirmed additional gains in muscle strength (of approximately 40%) with a 3-set RT protocol in comparison to single-set protocols (1,20,46). ...
... These studies have shown that low-volume RT, even as low as 1 set, increases muscle strength in older people (1,12,20,46,47). However, 3 of these studies have confirmed additional gains in muscle strength (of approximately 40%) with a 3-set RT protocol in comparison to single-set protocols (1,20,46). Consequently, the RT protocol with moderate-to-heavy loads and 3-set volume has been recommended to counteract sarcopenia (2,3,6,53). ...
We studied the effects of two different resistance training (RT) multiple-set protocols (three and six sets) on muscle strength and basal hormones concentrations in postmenopausal women (PW). Thirty-four PW were randomly allocated into three groups: control (CT, n=12), low RT volume (LV = three sets for each exercise, n=10) and high RT volume (HV = six sets for each exercise, n=12). The LV and HV groups performed eight exercises of a total body RT protocol three times a week, at 70 % of one repetition maximum (1RM) for 16 weeks. The muscle strength and basal hormones concentration were measured before and after the RT. Our findings show that three sets or six sets at 70% of 1RM protocol increased muscular strength similarly after 16 weeks (sum of all exercises, LV: 37.7% and HV: 34.1% vs. CT: 2.1%, p < 0.001). Moreover, the RT volume does not affect basal levels of testosterone (TT) (LV: 0.02%, HV: -0.12% and CT: 0.006%, p = 0.233), cortisol (C) (LV: 72.4%, HV: 36.8% and CT: 16.8%, p = 0.892), insulin-like growth factor-1 (LV: 6.7%, HV: 7.3% and CT: 4.1%, p = 0.802), dehydroepiandrosterone sulfate (LV: 0.1%, HV: -4.5% and CT: -6.7%, p = 0.885) and TT:C ratio (LV: -0.9%, HV: -1.6% and CT: -0.4%, p = 0.429). Our results suggest that three sets and six sets at 70% of 1RM seem to promote similar muscle strength gain. Thus, three set RT is a time efficient protocol for strength gain after 16 weeks in PW.
... Low-volume RT (i.e., one set per exercise) saves time, promotes positive muscle adaptations (5-7) and improves physical performance (7) in older individuals. Nevertheless, moderate to high intensity is a common practice in these studies that examined low-volume RT protocols (5)(6)(7). Given that a greater perception of poor health, of di culty, of discomfort (and pain), and of enjoyment are also cited as barriers to higher-intensity RT (HI-RT) practice (4), it can be argued that the using heavier loads may not be appropriate for everyone and may hinder or even prevent participation in a RT routine (4). ...
... The requirement for high volume (i.e., multiple sets) in LI-RT implies a lengthy training session that may hinder or prevent participation in RT routines. Since studies investigating the role of LI-RT on sarcopenia indicators only used multiple sets (5)(6)(7), little is known about the effects of LI-RT when a low-volume protocol is performed, particularly in older adults. However, previous research by our group has shown that when performed close to concentric failure, one set of LI-RT is enough to promote an increase in MM and MS in young men (12). ...
This study investigated the impact of intensity in a low-volume RT on sarcopenia indicators in postmenopausal women (PTW). Thirty-two participants were randomly assigned to either a control group (CT, n = 10), a LL-RT group (n = 10) that performed one set of 25–30 repetition maximum per exercise or a high-load RT group (HI-RT, n = 12) that performed one set of 8–12 repetition maximum per exercise. The RT groups performed 8 exercises, with 90 seconds of rest between exercises, 2 times a week for 24-weeks. Muscle mass (MM) of limbs (upper and lower) was assessed by DEXA, muscle strength (MS) was measured by the 1-RM leg press test, and physical performance by the TUG test and the 30-second sit to stand test. The ANCOVA (covariates: age, antihypertensive drugs, hormone replacement therapy and pre-time values) was used to analyze the gains (Δ) between groups, with a significance level of 5%. After 24-weeks of RT, lower and upper limb MM (together/summed) increased in both HI-RT (Δ = 0.60 kg; 95% CI: 0.23–1.0 kg) and LI-RT (Δ = 0.48 kg; 95% CI: 0.06–0.91 kg) in relation to CT (Δ=-0.03 kg; 95% CI: -0.43–0.37 kg) with no difference between them (p = 0.016; ƞ²=0.27 (large); observed power = 0.83). However, upper limb MM increased only in the HI-RT. For MS, the HI-RT group (Δ = 40 kg; 95% CI: 21–58 kg) showed greater gains compared to the CT (Δ = -5 kg; CI 95%: -24–14 kg) and LL (Δ = 12 kg; 95% CI: -8–33 kg) (p = 0.001 η ² = 0.35, Power = 0.98). Even though LI-RT promotes MM gains in lower limbs, HI-RT should be considered in low-volume training to promote gains in MS and also in MM in upper limbs in the PTW.
... However, the most appropriate prescription of RT variables in healthy older adults for enhancing muscular adaptations is not yet well established [5,8,9]. Among the plethora of RT variables, the number of sets seems to play a significant role in the adaptive response to RT programs because it can influence both training volume and intensity [10][11][12][13]. ...
... Although recent studies have reported similar results between single-set and multiple set RT programs for outcomes such as muscular strength [6,14], skeletal muscle mass [10,14], fat mass [13], bone mineral density [14], intracellular water [15], phase angle [16], muscle quality [15,16], IGF-1 [10] in untrained older women, it is believed that for trained individuals the use of multiple sets may be fundamental to avoid an adaptative plateau. On the other hand, little is known about the effects of reducing the number of sets per exercise in RT programs on adaptative responses [17,18]. ...
We compared the effects of different resistance training (RT) volume reduction strategies on muscular strength and lean soft-tissue (LST) in older women. Fifty seven physically independent women (> 60 years) performed a 20-week pre-conditioning phase of a standardized whole-body RT program (eight exercises, three sets, 8-12 repetitions, three sessions a week), and were then randomly assigned to one of the following conditions: reduced volume for a single-set (RV1, n = 20) or two sets (RV2, n = 19), or maintained volume of three sets (MV, n = 18) for eight weeks (specific-training phase). Muscular strength in the chest press, leg extension, and preacher curl exercises was determined by one-repetition maximum tests. A dual-energy X-ray absorptiometry device was used to estimate LST. An increase in muscular strength (16.3–32.1%) and LST (3.2–7.9%) was observed after the pre-conditioning phase. There was an increase in chest press for all groups (9.4–16.7%) after the specific-training phase. In contrast, only MV increased significantly in the leg extension (4.4%). No between-group differences were revealed for LST in the specific-training phase. Our results suggest that re-duced-RT volume from three to one set per exercise for eight weeks seems sufficient to retain neuro-muscular adaptations in older women.
... These inconsistencies may be associated with the studied muscle groups because different strength gains have been observed in lower-and upper-body muscles in response to training volume 3,5,9,10 . In a specific analysis for lower-body muscles (e.g., knee extensor muscles), some studies have reported greater strength gains with high-volume training than low-volume (3 sets vs.1 set) 3,5,11 , whereas others reported similar results 6,9,[12][13][14] . Therefore, there is a still controversy as to whether multiple sets protocols are more effective than single set protocols for increasing lower-body muscle strength. ...
... The short-and longterm studies 3,5,10 that reported superior effects for 3 sets in young subjects used a higher training intensity (load for 7RM in each set that which corresponds to an intensity >80% of 1RM, and 3 exercises for quadriceps muscle) compared to our study and others 6,12 that used a load range between 8-12RM (75-80% of 1RM, and 1-2 exercises for quadriceps muscle). Curiously, similar responses have been observed in elderly subjects: additional effects on knee extension 1RM gains was reported when a higher training volume (3 sets) was associated with moderate (10-15RM) 11 , but not low-(15-20RM) 13 or predominantly low-intensity (80% of training period with 15-20RM) 20 . Thus, it is possible that 3 sets are more effective than 1 set for increased lower-body muscles 1RM strength when higher intensity are used in young (e.g., > 80% of 1RM) and elderly (e.g., > 70% of 1RM) subjects. ...
... These inconsistencies may be associated with the studied muscle groups because different strength gains have been observed in lower-and upper-body muscles in response to training volume 3,5,9,10 . In a specific analysis for lower-body muscles (e.g., knee extensor muscles), some studies have reported greater strength gains with high-volume training than low-volume (3 sets vs.1 set) 3,5,11 , whereas others reported similar results 6,9,[12][13][14] . Therefore, there is a still controversy as to whether multiple sets protocols are more effective than single set protocols for increasing lower-body muscle strength. ...
... The short-and longterm studies 3,5,10 that reported superior effects for 3 sets in young subjects used a higher training intensity (load for 7RM in each set that which corresponds to an intensity >80% of 1RM, and 3 exercises for quadriceps muscle) compared to our study and others 6,12 that used a load range between 8-12RM (75-80% of 1RM, and 1-2 exercises for quadriceps muscle). Curiously, similar responses have been observed in elderly subjects: additional effects on knee extension 1RM gains was reported when a higher training volume (3 sets) was associated with moderate (10-15RM) 11 , but not low-(15-20RM) 13 or predominantly low-intensity (80% of training period with 15-20RM) 20 . Thus, it is possible that 3 sets are more effective than 1 set for increased lower-body muscles 1RM strength when higher intensity are used in young (e.g., > 80% of 1RM) and elderly (e.g., > 70% of 1RM) subjects. ...
Aims: The purpose of this study was to examine the effects of training volume (1 vs. 3 sets) on lower-body muscle strength in untrained young men. Methodsː Eighteen untrained young men were recruited and their legs were trained with 1 or 3 sets (in a contralateral design) for 6 weeks, using a knee extension machine. Isokinetic peak torque and one repetition maximum (1RM) were assessed at pre- and post-training. Resultsː There was a similar improvement in the 1RM strength (1SET: +14.8% vs. 3SET: 16.3%, P > 0.05) and peak torque (1SET: +8.1% vs. 3SET: 9.3%, P > 0.05) for both conditions from pre- to post-training. The effect size (ES) for the change in 1RM was moderate for both conditions (1SET: 1.39 vs. 3SET: 1.41), and peak torque was trivial and small for 1SET (0.47) and 3SET (0.55), respectively. Additionally, there were no significant (P > 0.05) differences in the dietary intakes from pre- to post-training. Conclusionsː Our results indicate that 1 set is as effective as 3 sets for increasing lower-body muscle strength after a short-term RT period (6 weeks) in untrained young men.
... Thus, no direct comparisons can be made with previous studies. However, studies investigating different training volumes, by manipulating the number of sets per exercise, did not find significant differences in body fat decreases between higher and lower volume RT programs [29,35]. Nunes et al. [29] investigated the effects of a 16-week RT program (8 exercises, 3 times a week, 70 % of 1RM) on body fat in 32 post-menopausal women who were separated into 3 groups: a group that performed 3 sets per exercise, a group that performed 6 sets per exercise, and a control group. ...
... Results showed no differences between the training groups for total fat mass decrease estimated by skinfolds. A previous study from our laboratory [35] compared 1 versus 3 sets per exercise in older women ( ≥ 60 years old) in a 12-week RT program. Results showed no significant difference in total body fat reductions, determined by DXA, between protocols. ...
Aim This study compared the effect of different resistance training (RT) frequencies on total, android, gynoid and trunk body fat in overweight/obese older women.
Methods Fifty-seven overweight/obese older women (66.9±5.3 years and 39.9±4.9% body fat) were randomly assigned to one of three groups: a group performing RT twice a week (G2X), a group performing RT three times a week (G3X), or a non-exercise control group (CG). Both training groups performed the same 12-week RT program consisting of 8 exercises that trained all major muscle groups. Dual-energy X-ray absorptiometry was used to assess body composition.
Results After the intervention period, both G2X and G3X demonstrated significant (P<0.05) reductions in adiposity compared to the CG for total body fat (G2X=–1.7%, G3X=–2.7%, CG=+2.1%), android fat (G2X=–6.2%, G3X=–7.0%, CG=+8.6%), gynoid fat (G2X=–2.5%, G3X=–2.9%, CG=+1.0%), and trunk fat (G2X=–2.5%, G3X=–3.0%, CG=+2.9%), with no significant differences between training groups.
Conclusion These results demonstrate that a low-volume 12-week RT program performed two or three times per week causes decreases in total and regional fat deposition with the greatest reductions occurring in the android region.
... Resistance training (RT) has been shown to promote improvements in the health of older populations (ACSM, 2009(ACSM, , 2011Westcott, 2012), with well-established positive effects on muscle strength and muscle growth (Fiatarone et al., 1990;Ribeiro et al., 2015;Souza et al., 2017). Recent findings suggest that RT can promote improvements in phase angle (PhA), a bioimpedance-derived value largely used as an indicator of cellular health and functionality, and cell membrane integrity (dos Santos, Cyrino, Antunes, Santos, & Sardinha, 2016;Norman, Stobäus, Pirlich, & Bosy-Westphal, 2012;Ribeiro et al., 2017;Souza et al., 2017), and positively change muscle quality (MQ) Ribeiro et al., 2016), herein referred to the ratio between muscle mass and strength muscular (Fragala, Kenny, & Kuchel, 2015); both of which are important variables related to enhanced functional capacity of older adults (Barbat-Artigas et al., 2013;Tomeleri et al., 2017). ...
... Galvão and Taaffe (2005) noted greater gains in isotonic and isometric strength in a 3-set group compared to a 1-set group but no difference in several functional performance tests. Thus, although studies have analyzed other variables, they show a lack of consensus on the different responses to single-set and multiple-set protocols (Ribeiro et al., 2015;Radaelli et al., 2013;. ...
The main purpose of this study was to compare the effects of resistance training (RT) performed with different training volumes on phase angle (PhA), body water components, and muscle quality (MQ) in untrained older adult women. A second purpose was to assess the relationship between PhA and MQ. Sixty-two older adult women (68.6 ± 5.0 years, 65.2 ± 13.3 kg, 156.1 ± 6.2 cm) were randomly assigned into one of the three groups: two training groups performed either 1 set (G1S) or 3 sets (G3S), or a control group (CG). Body water components and PhA were estimated by bioelectrical impedance (BIA). MQ was determined by dividing skeletal muscle mass estimated by dual-energy absorptiometry (DXA) by total muscle strength from three exercises. After the 12-week intervention period, both training groups demonstrated improvements (P < 0.05) when compared with CON for intracellular water, total body water, PhA, and MQ. These results suggest that RT can improve PhA, body water components, and MQ in untrained older women, regardless of training volume. Furthermore, changes in MQ were positively correlated with changes in PhA (r = 0.60, P < 0.01).
... Nevertheless, several studies have analyzed each component individually in the target population. Regarding muscular strength, the higher increases observed in G3S vs. G1S are in agreement with previous work from our laboratory in another cohort of older women (Ribeiro et al., 2015). A meta-analysis indicates that multiple (2-3 sets) sets are superior than single set to elicit muscular strength (Krieger, 2010). ...
... This hypothesis was confirmed in our experiment. However, a previous study from our laboratory comparing 1 versus 3 sets per exercises in another cohort of older women (Ribeiro et al., 2015) failed to observe such differences between protocols. Recently, Nunes et al. (2016) investigated the effects of a 16-weeks RT program (8 exercises, 3 times a week, 70% of 1RM) on body fat in 32 post-menopausal women who were separated into 3 groups: a group that performed 3 sets per exercise, a group that performed 6 sets per exercise, and a control group. ...
The aim of this study was to analyze the effects of resistance training (RT) performed with 1 or 3 sets per exercise on osteosarcopenic obesity (OSO) syndrome parameters in older women. Sixty-two older women (68.0±4.3 years, 26.8±4.4 kg/m2) participated in a 12-week RT program. Participants were randomly assigned into one of the three groups: two training groups that performed either 1 set (G1S, n= 21) or 3 sets (G3S, n= 20) 3 times weekly, or a control group (CG, n= 21). Body composition was assessed by dual X-ray absorptiometry, strength was evaluated by 1 repetition maximum testing. The G3S presented significantly higher strength changes than G1S. The changes for percentage of body fat were higher for G3S compared to G1S. There was no difference in skeletal muscle mass between G3S and G1S, however both training groups displayed greater increases in this outcome compared to CG. There was no effect for bone mineral density. The overall analysis indicated higher (P<0.05) positive changes for G3S than G1S (composed Z-score: G3S=0.62±0.40; G1S=0.11±0.48). The results suggest that a 12-week RT period is effective to improve the risk factors of OSO, and that 3 sets induce higher improvements than a single set.
... Although SSFT improved the Five times sit-to-stand test performance, the MSFT was superior, like previously published results (Ribeiro et al., 2015;Barbalho et al., 2017). The improvement in both groups could be attributed to the specificity of the squatting action and the higher number of lower limb exercises. ...
Introduction: Aging can be associated with reduced muscle power, functional decline, and increased plasma concentrations of proinflammatory cytokines. Functional training (FT) can improve muscle power, functional fitness and reduce plasma cytokines. However, the functional training optimal volume required to produce these adaptations must be clarified. Our study analyzed the effects of multiple–set functional training (MSFT) and single–set functional training (SSFT) on postmenopausal women’s muscle power, functional fitness, and inflammatory profile.
Methods: Forty–three women were randomly allocated into three groups: multiple–set functional training ( n = 16, age 64.13 ± 5.17), single–set functional training ( n = 14, age 63.79 ± 4.88), and control group (CG, n = 13, age 64.62 ± 5.44). The bench press and squat exercises evaluated upper and lower limb muscle power. The following tests assessed functional fitness: putting on and taking off a T–shirt, gallon–jug shelf–transfer, standing up and walking around the house, five times sit–to–stand, and 400–m walk. Plasma cytokine (TNF–α, IL–6, and IL 10) concentrations were measured by flow cytometry.
Results: Single–set functional training and multiple–set functional training increased upper and lower limbs muscle power and improved functional fitness, except for the putting on and taking off a T–shirt test. Multiple–set functional training reduced TNF–α and IL–6, while single–set functional training reduced only TNF–α. IL–10 was unaffected by exercise.
Discussion: Single–set functional training and multiple–set functional training, therefore, promoted similar muscle power and functional fitness improvements over 24 weeks. Multiple–set functional training was more effective than single–set functional training, reducing both TNF and IL–6, while single–set functional training only decreased TNF–α.
... The authors reported that strength gains did not differ between the high-intensity groups but were significantly greater than in the 30%-3 group (P = 0.04). Ribeiro et al. (2015) examined strength and hypertrophy in 32 randomly allocated elderly women after 12 weeks of performing 1 or 3 sets per session of full-body resistance training. Dual-energy x-ray absorptiometry (DXA) was used to assess hypertrophy. ...
Skeletal muscle is one of the most important tissues of the human body. It comprises up to 40% of the body mass and is crucial to survival. Hence, the maintenance of skeletal muscle mass and strength is pivotal. It is well-established that resistance exercise provides a potent anabolic stimulus to increase muscle mass and strength in men and women of all ages. Resistance exercise consists of mechano-biological descriptors, such as load, muscle action, number of repetitions, repetition duration, number of sets, rest interval between sets, frequency, volitional muscular failure, and range of motion, which can be manipulated. Herein, we discuss the evidence-based contribution of these mechano-biological descriptors to muscle mass and strength.
... This result is important considering that muscle mass decreases with age (English & Paddon-Jones, 2010), and this decrease is associated with various negative outcomes that could be attenuated or prevented by SSRT. In addition, although SSRT load has been suggested to provide an insufficient stimulus to induce hypertrophy since the load found in descriptive studies with up to a couple of sessions was of low-to-moderate intensity (Elsangedy et al., 2013Focht, 2007;Focht et al., 2015;Portugal et al., 2015), the FFM increase found in the present study (þ5%) was similar to findings of several studies that applied the RT load recommended by the ACSM to similar participants, as described above (Nascimento et al., 2018;Ribeiro et al., 2015Ribeiro et al., , 2016Ribeiro et al., , 2017Santos et al., 2018;Tomeleri et al., 2016). For example, while some studies found increases in appendicular muscle mass of 2.6-5.7% after eight weeks of a traditional (3 x 8-12 RMs) or pyramidal (3 x 12/10/8 RMs) RT program or 5.5-5.8% with one set of 10-15 maximum repetitions after 12 weeks (Nascimento et al., 2018), others found only 1.1-1.6% ...
This study aimed to investigate the effects of a 12-week self-selected resistance training (SSRT) program on physical fitness and psychophysiological responses among physically inactive older women. We randomly allocated 32 inactive older women (M age = 66.0 years, SD = 3.0) into either an SSRT (n = 16) or control group (n = 16). Participants performed SSRT three times per week over 12 weeks. We assessed maximal isotonic and isokinetic muscle strength, functional capacity, flexibility, cardiorespiratory fitness, and body composition at baseline and after the intervention. Affective responses and perceived exertion were evaluated after each exercise set throughout the training program. The SSRT group significantly improved their maximal muscle strength in all exercises (Cohen’s d ranging from 1.4-3.3; all p’s < .001), peak torque (knee flexors: d = 1.7; knee extensors: d = 1.6; all p < .001), flexibility (knee flexors: d = 1.7; single hip flexors: d = 1.6; all p < .001; bilateral hip flexors: d = 1.1, p = .001), fat-free mass (d = .9, p = .008), and cardiorespiratory fitness (d = .9, p = .014), compared to the control group. All components of functional capacity improved compared to the control group (Cohen’s d ranging from .8 to 5.5; all p’s ≤ .001). Participants perceived the exercise training sessions as pleasant and of low to moderate effort. Thus, a 12-week SSRT program was effective at improving physical fitness and inducing feelings of pleasure among inactive older women.
... To the best of our knowledge, this is the first study to compare the effects of different volumes of RT on OS biomarkers in older women. Although other studies with different volumes of RT have analyzed variables like body composition or muscular strength in older women (9,29), we assessed the effect of RT volume on OS biomarkers and the balance of interrelated systems, which is especially important given that these individuals are at a greater risk for the development of diabetes, cardiovascular disease, and others impairments on health (14,35). In a recent study, Alikhani et al. (3) found that RT improves OS and inflammatory biomarkers in older and young individuals. ...
The purpose of the present study was to investigate the effects of resistance training (RT) performed with a higher versus lower training volume on oxidative stress (OS) biomarkers in older women. Thirty-eight older women (≥ 60 years) were randomly assigned to one of two groups: a group that performed one set per exercise (LV, n = 18), or 3 sets per exercise (HV, n = 20). The whole-body RT consisted of a 12-week RT program involving 8 exercises performed with sets of 10-15 repetitions maximum, 3 days/week. Advanced oxidation protein products (AOPP), total radical-trapping antioxidant potential (TRAP) and ferrous oxidation-xylenol orange (FOX) were used as OS biomarkers. The composite Z-score of the percentage changes from pre- to post-training of OS biomarkers according to groups was calculated. A significant main effect of time (p < 0.05) was found for AOPP (LV = -7.3% vs. HV = -12.2%) and TRAP (LV = +1.5% vs. HV = +15.5%) concentrations, without a statistical difference between groups (p > 0.05). A significant group vs. time interaction (p < 0.001) was revealed for FOX (LV = +6.4% vs. HV = -8.9%). The overall analysis indicated higher positive changes for HV than LV (Z-score: HV = 0.41 ± 1.22 vs. LV = -0.37 ± 1.03, p < 0.05). Our results suggest that a greater volume of RT seems to promote superior improvements on OS biomarkers in older women.
... 632 protein intake below the recommended and necessary level for optimal RT-adaptations (25), it is plausible that reduced protein intake would minimize the expected differences in LST gains between different RT protocol volumes. Differences between studies regarding gains on LST could be designated to the lack of assessment of dietary intake (12,30,33,39,40), as previously stated (30). ...
The purpose of this study was to analyze the effects of 24 weeks of resistance training (RT) performed 2 vs. 3 times per week on muscle strength, muscle mass, and muscle quality in older women. Thirty-nine older women (≥ 60 years old) were randomly assigned to two groups according to RT frequency (G2x = two sessions per week, n=19; and G3x = three sessions per week, n=20) and were submitted to 24 weeks of whole-body RT, divided into two stages of 12 weeks. In the first stage, participants performed 1 set of 10 to 15 repetitions in each of eight exercise, whereas in the second stage, they performed 2 sets of 10 to 15 repetitions. Muscle strength was assessed by one repetition maximum (1RM) tests in chest press, knee extension, and biceps preacher curl, while the lean soft tissue was estimated by DXA. The muscle quality index was determined by the ratio between strength and lean soft tissue. There were observed similar increases between groups for muscle strength (G2x=19.5%; G3x=22.2%), lean soft tissue (G2x=3.0%; G3x=1.6%), and muscle quality index (G2x=16.0%; G3x=21.1%). These results indicate that RT-induced muscular adaptation occurs regardless of training twice or thrice a week in older women. Instructors, coaches and practitioners can choose their training frequency preference, since both frequencies provided similar adaptations.
... However, there are also contradictory results. Ribeiro et al. (2015a) found no significant differences in changes in body composition, specifically fat mass and muscle mass, between older women performing a one-set or three-set RT protocol three-times-a-week. They concluded that in the initial state of training both volumes led to similar results. ...
The main purpose of the present study was to investigate the effect of frequency, thereby increasing training volume, of resistance training on body composition, inflammation markers, lipid and glycemic profile in healthy older individuals (age range 65–75 year). Ninety-two healthy participants were randomly assigned to one of four groups; performing strength training one- (EX1), two- (EX2), or three- (EX3) times-per-week and a non-training control (CON) group. Whole-body strength training was performed using 2–5 sets and 4–12 repetitions per exercise and 7–9 exercises per session. All training groups attended supervised resistance training for 6 months. Body composition was measured by dual X-ray absorptiometry and fasting blood samples were taken pre- and post-training. There were significant main effects of time for total fat mass (F = 28.12, P < 0.001) and abdominal fat mass (F = 20.72, P < 0.001). Pre- to post-study, statistically significant reductions in fat mass (Δ = -1.3 ± 1.4 kg, P < 0.001, n = 26) were observed in EX3. Pre- to post-study reductions in low density lipoprotein (LDL) concentration (Δ = -0.38 ± 0.44 mmol⋅L-1, P = 0.003, n = 19) were observed only in EX3, whereas a significant pre- to post-study increases in high density lipoprotein (HDL) concentration (0.14–0.19 mmol⋅L-1) were observed in all training groups. Most variables at baseline demonstrated a significant (negative) relationship when correlating baseline values with their change during the study including: Interleukin-6 (IL-6) (r = -0.583, P < 0.001), high-sensitivity c-reactive protein (hs-CRP) (r = -0.471, P < 0.001, and systolic blood pressure (r = -0.402, P = 0.003). The present study suggests that having more than two resistance training sessions in a week could be of benefit in the management of body composition and lipid profile. Nevertheless, interestingly, and importantly, those individuals with a higher baseline in systolic blood pressure, IL-6 and hs-CRP derived greatest benefit from the resistance training intervention, regardless of how many times-a-week they trained. Finally, the present study found no evidence that higher training frequency would induce greater benefit regarding inflammation markers or glycemic profile in healthy older adults.
... especially relevant because their relation to the reduction of morbidities associated with aging such as frailty, sarcopenia, functional deterioration, or morbi-mortality. It is in accordance with the results of Cavalcante et al. [16], Fourie et al. [24] and Rogers [40] but differs from those of Bergamin et al. [19], Segal et al. [41], and Ribeiro et al. [42]. Some variables of training such as volume, density, intensity, or complexity of exercise could be the cause of obtaining significant changes in body composition [24]. ...
Objectives:
The goal was to analyze the effect of two different training programs on functional autonomy, balance, and body composition in aged women and to determine the influence of their cognitive function.
Methods:
Older women aged between 60 to 80 years old were invited to participate in the study. A block randomisation method was used to allocate participants to the Pilates group (PEP), the Muscular group (MEP) and the control group (CG) with equal sample sizes (n = 20). PEP or MEP were required to train twice a week (1 hour/session) in a moderate to vigorous intensity for 18 weeks. Functional autonomy was assessed with the GDLAM protocol. The cognitive function, withthe Mini-Mental State (MMS). Static balance, with a force platform (Kistler 9286AA). Body composition, with a dual-energy X-ray bone densitometry. Research staff performing the assessment and statistical analysis was blinded.
Results:
Eighty participants were randomized, 16 women did not meet the inclusion criteria and 4 refused to participate. 60 participants were analysed. Either Pilates or Muscular group improved significantly (P ≤ 0.05) in every GDLAM test. Pilates had a better general functional condition index (IG) than the Muscular group (P = 0.042). There was a significant interaction (P ≤ 0.05) between the cognitive function and two items of the GDLAM test. The amplitude of displacement of the center of pressure in the antero-posterior plane decreased significantly in the Muscular group (P = 0.04). The total lean body increased in the Pilates (P =< .001) and the Muscular groups (P = 0.05).
Conclusions:
Pilates should be recommended for improving the general functional condition of older women, while the Muscular exercise is effective for enhancing the static balance. Both exercise programs are effective for increasing the total lean body. The cognitive function interacts with some functional autonomy parameters Trial registration: ClinicalTrials.gov (identifier: NCT02506491; available from https://clinicaltrials.gov/show/NCT02506491).
... Several studies have evaluated the use of lower-compared to higher-training volumes, supporting the efficacy of lower training volume in body composition, muscle thickness, and strength (6,(14)(15)(16), while some studies show a superiority for higher volumes of training (17)(18)(19)(20). Meta-analyses by Schoenfeld et al. (10) and Ralston et al. (21) noted a linear dose-response relationship suggesting the superiority of higher volume training and recommended that, for maximizing muscle hypertrophy and strength respectively, one should perform at least 10 sets per week for each muscle group. ...
Introduction: The purpose of the present study was to compare the effects of different volumes of resistance training (RT) on muscle performance and hypertrophy in trained women. Methods: The study included 40 volunteers that performed RT for 24 weeks divided in to groups that performed five (G5), 10 (G10), 15 (G15) and 20 (G20) sets per muscle group per session. Ten repetition maximum (10RM) tests were performed for the bench press, lat pull down, 45º leg press, and stiff legged deadlift. Muscle thickness (MT) was measured using ultrasound at biceps brachii, triceps brachii, pectoralis major, quadriceps femoris, and gluteus maximus. Results: All groups significantly increased all MT measures and 10RM tests after 24 weeks of RT (p<0.05). Between group comparisons revealed no differences in any 10RM test between G5 and G10 (p>0.05). G5 and G10 showed significantly greater 10RM increases than G15 for lat pulldown, leg press and stiff legged deadlift. 10RM changes for G20 were lower than all other groups for all exercises (p<0.05). G5 and G10 showed significantly greater MT increases than G15 and G20 in all sites (p<0.05). MT increased more in G15 than G20 in all sites (p<0.05). G5 increases were
higher than G10 for pectoralis major MT, while G10 showed higher increases in quadriceps MT
than G5 (p<0.05). Conclusions: Five to 10 sets per week might be sufficient for attaining gains
in muscle size and strength in trained women during a 24-week RT program. There appears no
further benefit by performing higher exercise volumes. Since lack of time is a commonly cited
barrier to exercise adoption, our data supports RT programs that are less time consuming, which
might increase participation and adherence.
... Given the aforementioned effects of aging and inactivity, resistance training (RT) has been employed for older adults to attenuate or possibly reverse the numerous changes resulting from the natural aging process (8). Resistance training has been shown to increase muscle strength (1,13,34,43), improve cognitive function (11), enhance functional capacity (43,45), reduce some anthropometric measures (i.e., body mass, circumferences), and alter body composition components by augmenting FFM (13,36,41,43). ...
The aim of our study was to compare the agreement between bioelectrical impedance (BIA) and dual-energy X-ray absorptiometry (DXA) to track changes on fat-free mass (FFM) after a resistance training (RT) program in older women. Forty-three older women (65.2 ± 4.6 years, 59.5 ± 9.2 kg, 156.4 ± 6.0 cm, 24.3 ± 3.3 kg·m) participated in a RT intervention (12 weeks, 8 exercises, 2 sets, 10-15 repetitions, 3 nonconsecutive days per week). Fat-free mass changes were determined by a single-frequency BIA device (EQ1), 6 BIA prediction equations for older women (EQ2, EQ3, EQ4, EQ5, EQ6, and EQ7), and DXA. At pretraining, 3 equations overpredicted, and 3 underpredicted DXA FFM (F = 244.63, p < 0.001), although all equations had high correlations with DXA (r = 0.78-0.83). After training, 4 equations overpredicted and one underpredicted DXA FFM (F = 176.25, p < 0.001). Dual-energy X-ray absorptiometry detected significant gains in FFM (0.65 ± 0.82 kg; p < 0.05), as did EQ3 (0.55 ± 1.69 kg; p < 0.05), and EQ4 (0.61 ± 1.88 kg; p < 0.05), whereas the remaining equations did not indicate significant changes in FFM. Low correlations between FFM and equation change values suggest that single-frequency BIA-derived equations may not provide sufficient accuracy to track changes in FFM after 12 weeks of RT in older women.
... Given the aforementioned effects of aging and inactivity, resistance training (RT) has been employed for older adults to attenuate or possibly reverse the numerous changes resulting from the natural aging process (8). Resistance training has been shown to increase muscle strength (1,13,34,43), improve cognitive function (11), enhance functional capacity (43,45), reduce some anthropometric measures (i.e., body mass, circumferences), and alter body composition components by augmenting FFM (13,36,41,43). ...
The aim of our study was to compare the agreement between bioelectrical impedance (BIA) and dual-energy X-ray absorptiometry (DXA) to track changes on fat-free mass (FFM) after a resistance training (RT) program in older women. Forty-three older women (65.2 ± 4.6 years, 59.5 ± 9.2 kg, 156.4 ± 6.0 cm, 24.3 ± 3.3 kg·m) participated in a RT intervention (12 weeks, 8 exercises, 2 sets, 10-15 repetitions, 3 nonconsecutive days per week). Fat-free mass changes were determined by a single-frequency BIA device (EQ1), 6 BIA prediction equations for older women (EQ2, EQ3, EQ4, EQ5, EQ6, and EQ7), and DXA. At pretraining, 3 equations overpredicted, and 3 underpredicted DXA FFM (F = 244.63, p < 0.001), although all equations had high correlations with DXA (r = 0.78-0.83). After training, 4 equations overpredicted and one underpredicted DXA FFM (F = 176.25, p < 0.001). Dual-energy X-ray absorptiometry detected significant gains in FFM (0.65 ± 0.82 kg; p < 0.05), as did EQ3 (0.55 ± 1.69 kg; p < 0.05), and EQ4 (0.61 ± 1.88 kg; p < 0.05), whereas the remaining equations did not indicate significant changes in FFM. Low correlations between FFM and equation change values suggest that single-frequency BIA-derived equations may not provide sufficient accuracy to track changes in FFM after 12 weeks of RT in older women.
... In the current study, the RT program followed the recommendations of the American College of Sports Medicine in order to induce morphologic, hemodynamic and metabolic changes in older adults [5]. In fact, our results showed increases in muscular strength Training & Testing Thieme and skeletal muscle mass and reductions in body fat in older women submitted to the RT program, which was expected and is in accordance with the literature [15,32]. Our study has some limitations that should be considered. ...
This study analyzed the effects of 12 weeks of resistance training (RT) on resting blood pressure (BP) and plasma levels of nitric oxide metabolites (NOx) in pre- and hypertensive older women, and evaluated the relationship between these 2 parameters. Thirty-five older women (68.2±5.7 years, 70.0±14.4 kg, 157.1±6.4 cm, 28.3±5.0 kg.m−2) were randomly allocated into a training group (TG; n=17), which performed a 12-week RT program, and a control group (CG; n=18), which did not perform any physical exercise. Anthropometry, one repetition maximum (1RM), body composition analysis by dual energy X-ray absorptiometry, blood samples, and resting BP were measured. There was a significant interaction for all variables analyzed, in which reductions of systolic BP (−8.5%), diastolic BP (−8.4%), and mean arterial pressure (−8.5%), and increases of NOx (+35.2%) were observed only for the TG. Moreover, a negative and significant correlation was observed (P<0.05; r=−0.63) between NOx and systolic BP in the TG. Results suggest that a 12-week RT program is sufficient to induce reductions in BP in pre- and hypertensive older women and that the decrease in systolic BP is associated with an increase in plasma NOx concentration.
... This suggests that upper body multijoint exercises should be included when counting the number of sets for arm muscles. This was not performed in the studies of Correa et al. (2015), Ostrowski et al. (1997), Radaelli et al. (2015) , and Ribeiro et al. (2015), and does not appear to have been accounted for in the analyses of Schoenfeld et al. ...
... Due to physiological decline during ageing existing muscle mass in humans and the force that reaches peak levels between the second and fourth decades of life suffers a drop in percentage, it is estimated that we lost about 1/2% of our muscle mass per year, this percentile increases between 1% and 2% annually after 50 years and then the 3% annually after the age of 60 [2]. ...
Objective: Identify a score for the diagnostic assessment of health and body image based on anthropometric and biochemical measures in the elderly.
Method: Transversal research exploratory and quantitative approach, developed in the South of the city of João Pessoa-PB with 21 elderly practitioners of physical exercises in sport aerobics in the period of May to June 2015. It was used a sociodemographic questionnaire and the International Physical Activity questionnaire, IPAQ. The research was authorized by the ethics on Research Committee of the University Center of João Pessoa/PB, CAAE 38840214.7.0000.5176.
Results: The study subjects had an average age of 65.9 and standard deviation 6.92 years. It was observed in table 2 the importance of body fat Mass and waist hip as the most influential in lifestyle, according to the non-parametric test of McNemar suitable for dichotomous dependent data. In table 3 the importance of all variables with exception of Edema as the most influential in body image, according to the non-parametric test of McNemar
Conclusion: It is observed that the elderly present composition of body fat mass and relative CK high, according to the measure of proximity of Jaccard, thus most of the elderly are in opposition to a healthy lifestyle. It is essential for the understanding of the characteristics and the transformations that the individuals with the advancement of age which reinforces the need for more effective actions in the control and/or prevention of health-related factors in the elderly.
... The results of longitudinal research on the dose-response relationship between volume and muscle hypertrophy have been conflicting, with some studies showing that HV produce significantly greater adaptations (Correa et al., 2015;Radaelli, Fleck, et al., 2014;Rønnestad et al., 2007;Sooneste, Tanimoto, Kakigi, Saga, & Katamoto, 2013;Starkey et al., 1996) and other studies reporting no volume-based differences (Bottaro, Veloso, Wagner, & Gentil, 2011;Cannon & Marino, 2010;Galvao & Taaffe, 2005;McBride, Blaak, & Triplett-McBride, 2003;Mitchell et al., 2012;Ostrowski, Wilson, Weatherby, Murphy, & Little, 1997;Rhea, Alvar, Ball, & Burkett, 2002;Ribeiro et al., 2015). However, the small samples inherent in longitudinal training studies often compromise statistical power, thereby increasing the likelihood of a type II error. ...
The purpose of this paper was to systematically review the current literature and elucidate the effects of total weekly resistance training (RT) volume on changes in measures of muscle mass via meta-regression. The final analysis comprised 34 treatment groups from 15 studies. Outcomes for weekly sets as a continuous variable showed a significant effect of volume on changes in muscle size (P = 0.002). Each additional set was associated with an increase in effect size (ES) of 0.023 corresponding to an increase in the percentage gain by 0.37%. Outcomes for weekly sets categorised as lower or higher within each study showed a significant effect of volume on changes in muscle size (P = 0.03); the ES difference between higher and lower volumes was 0.241, which equated to a percentage gain difference of 3.9%. Outcomes for weekly sets as a three-level categorical variable (<5, 5-9 and 10+ per muscle) showed a trend for an effect of weekly sets (P = 0.074). The findings indicate a graded dose-response relationship whereby increases in RT volume produce greater gains in muscle hypertrophy.
... These findings suggest that a high volume (>three sets) is not necessary to promote additional strength gains in PW over LV. However, three sets have been reported to be better than one set to promote strength gains in older people (Alex et al. 2015;Galvao and Taaffe 2005;Radaelli et al. 2014). Following this viewpoint, this information suggests that three sets could be a possible volume threshold to strength gains in PW. ...
This study evaluated the effect of resistance training (RT) volume on muscular strength and on indicators of abdominal adiposity, metabolic risk, and inflammation in post-menopausal women (PW). Thirty-two volunteers were randomly allocated into the following three groups: control (CT, no exercise, n = 11), low-volume RT (LV, three sets/exercise, n = 10), and high-volume RT (HV, six sets/exercise, n = 11). The LV and HV groups performed eight exercises at 70 % of one maximal repetition, three times a week, for 16 weeks. Muscular strength and indicators of abdominal adiposity, metabolic risk, and inflammation were measured at baseline and after 16 weeks. No differences were found in baseline measures between the groups. The PW showed excess weight and fat percentage (F%), large waist circumference (WC), high waist-hip ratio (WHR), and hypercholesterolemia and borderline values of glycated hemoglobin (HbA1c%). Following the RT, a similar increase in muscle strength and reduction in F% from baseline were found in both trained groups. In HV, a decrease in total cholesterol, LDL-c, WC, and WHR was noted. Moreover, the HV showed a lower change (delta%) of interleukin-6 (IL-6) when compared to CT (HV = 11.2 %, P
25–75 = −7.6–28.4 % vs. CT = 99.55 %, P
25–75 = 18.5–377.0 %, p = 0.049). In LV, a decrease was noted for HbA1c%. There were positive correlations (delta%) between WHR and IL-6 and between IL-6 and TC. These results suggest that while a low-volume RT improves HbA1c%, F%, and muscular strength, a high-volume RT is necessary to improve indicators of abdominal adiposity and lipid metabolism and also prevent IL-6 increases in PW.
... Reductions in body fat in this investigation occurred without difference between groups. Previous research has shown decreased body fat in elderly women after a period of RT (Fiatarone et al., 1990;Ribeiro et al., 2015). These results may be, at least in part, attributed to similar increases in lean soft tissue, given its relationship with resting metabolic rate (Campbell et al., 1994;Hunter et al., 2000). ...
Kan glukozunun yükselmesiyle karakterize olan diyabet, pankreastaki fonksiyon bozukluğu neticesinde oluşmaktadır ve bu durum insülin etkisine karşı dirence veya insülin üretiminin azalmasına neden olmaktadır. Diyabet, Tip-I ve Tip-II olmak üzere iki grupta incelenmektedir. Tip-I diyabet, pankreasın beta hücresinden salınan insülin hormonundaki yetersizlik neticesinde gelişim göstermektedir. Burada T-hücresi aracılığıyla gerçekleşen otoimmün yanıtın, pankreasın beta hücre fonksiyonunu etkilediği bilinmektedir. Tip-II diyabet sağlıksız beslenme, hareketsizlik, genetik-çevresel faktörlerden kaynaklı gelişim göstermektedir. Prevalansı yüksek Tip-II diyabette, insülin direnci oluşumu, beta hücre fonksiyonunda kayıp ile hiperglisemi gelişmektedir. Tümör nekroz faktör ilişkili apoptoz indükleyici ligand (TRAIL), tümör nekroz faktör (TNF)-süper ailesinin üyesi olup; Tip-II transmembran proteini olarak ifade edilmektedir. İmmün yanıt ve inflamasyonun düzenlenmesinde önemli fonksiyonlara sahiptir. Biyolojik etkilerini, hücre yüzeyindeki reseptörleri sayesinde gerçekleştirmektedir. TNF-alfa’nın senteziyle oluşan lenfosit infiltratları, Tip-I diyabete yol açmaktadır. TRAIL’in diyabet gelişimindeki rolüyle ilgili çalışmalar ilk olarak hayvan modellemeleriyle başlamıştır. TRAIL eksikliği olan hayvan çalışmalarında, otoimmün kaynaklı diyabetin ve pankreatik adacık inflamasyonunun arttığı kaydedilmiştir. Bu bulgular TRAIL’in diyabet patofizyolojisinde önemli bir rol oynadığını göstermektedir. Klinik veriler neticesinde TRAIL ekspresyonunun sağlıklı bireylerde yüksek olması obezite ve diyabette koruyucu bir rolü olduğunu düşündürmektedir. Bu derlemede, elde edilen bulgular temelinde TRAIL’in diyabetteki koruyucu rolünün incelenmesi hedeflenmiştir.
Purpose:
Resistance training combined with appropriate dietary intake can promote a concomitant increase in skeletal muscle mass (SMM) and reduction in fat mass, a condition termed body recomposition. This study's primary purpose was to explore the effects of protein ingestion on body recomposition following 24 weeks of resistance training (RT) in older women.
Methods:
Data from 130 untrained older women (68.7 ± 5.6 years, 66.5 ± 11.5 kg, 155.5 ± 6.0 cm, and 27.4 ± 4.0 kg.m-2) across six studies were retrospectively analyzed. The participants were divided into tertiles according to their customary protein intake (g/kg/d): lower (LP, n = 45), moderate (MP, n = 42), and higher (HP, n = 43) protein intake. Participants performed a whole-body RT program carried out over 24 weeks (eight exercises, three sets, 8-15 repetitions, three sessions a week). SMM and fat mass were determined by dual-energy X-ray absorptiometry.
Results:
All groups increased SMM from baseline (P < 0.05), with the HP and MP groups showing greater increases than the LP group (LP = 2.3%, MP = 5.4%, and HP = 5.1%; P < 0.05). Reductions in fat mass were similar for all three groups (LP = 1.7%, MP = 3.7%, and HP = 3.1%; P > 0.05). The composite Z-score of the percentage changes from pre- to post-training indicated greater positive body recomposition values for HP and MP compared to LP (P < 0.05).
Conclusions:
Results suggest that protein intake is a moderating variable for body recomposition in older women undergoing RT, with a low protein intake having a less favorable effect on body recomposition.
This review describes the adherence characteristics and reasons for abandonment physical exercise-based interventions in older adults in Latin America. This scoping review was conducted in accordance with the PRISMA statement. Articles were searched in MEDLINE by PubMed, ELSEVIER by SCOPUS and SciELO. The MeSH terms «Exercise», Exercise Therapy» and «Aged» were used between 2015 and 2020. We searched for articles in Spanish, English, and Portuguese carried out in people aged 65 years and over.101 out of 4,642 randomized controlled trials (RCT) were included. A total sample of 5,013 older adults (79% women), with an average age of 68.2 years started their studies and 4,312 finished it, presenting an adherence to the interventions of 86%. Most of the studies were carried out in healthy older adults, in places enabled for the practice of physical activity, in charge of a physical activity professional, and the interventions were performed carried out through group therapeutic exercise. No article reported information on the minimum time of participation to the session to be considered as carried out. Only 30% of the articles reported the minimum participation of older adults in the intervention to include them in the study analysis, and 21% reported the average number of sessions attended to the intervention. The main reasons for abandonment were personal causes unrelated to the intervention. Only 5% of the articles reported injury of one of the participants (in two of them the injury was related to the intervention applied). This review characterized the physical exercise programs in older adults in Latin America, as well the adherence characteristics and the main reasons for abandonment to physical exercise-based interventions, by summarizing available evidence derived from RCTs. © Federación Española de Asociaciones de Docentes de Educación Física (FEADEF).
Obesity is a multifactorial disease with an increasing prevalence worldwide and is characterized by an increase in body weight. It poses a risk for diseases such as hypertension and diabetes, especially by causing an increase in fat in the abdominal area. Obesity can be managed through behavioral changes in energy intake or expenditure. Various nutrition and exercise strategies are used for this purpose. Exercise causes an increase in energy expenditure and contributes to a decrease in body weight, loss of fat mass and the maintenance of these effects. Exercise has the potential to mitigate the adverse health consequences of obesity even without weight loss in the body. Studies suggest that resistance exercise training can promote a negative energy balance, play a role in weight management by changing body fat mass. Increase in muscle mass with resistance exercise training provides a better metabolic control in the body. From the perspective of weight loss and control, recent exercise guidelines include resistance exercise training as part of an exercise prescription. Resistance exercise training can play an important role in body fat management, with an increase in energy expended during physical activity and an acute increase in basal metabolic rate. Resistance exercise training can increase lean body mass and cause changes in body composition by reducing visceral and total body fat. However, the effects of resistance exercise training on body fat composition still do not give definitive results. In this respect, this review aims to examine the effects of resistance exercise training on body fat mass and muscle.
Aim:
To characterize physical exercise programs for older adults in Latin America.
Methods:
This review was conducted in accordance with the PRISMA statement. A search for randomized controlled trials (RCTs) published between the years 2015 and 2020 was performed in the Scopus, MedLine and SciELO databases.
Results:
A total of 101 RCTs were included. A large percentage of the studies had an unclear risk of bias in the items: selection, performance, detection and attribution. Furthermore, a heterogeneous level of compliance was observed in the CERT items. A total sample of 5013 older adults (79% women) was included. 97% of the studies included older adults between 60-70 years, presenting an adherence to the interventions of 86%. The studies were mainly carried out in older adults with cardiometabolic diseases. Only 44% of the studies detailed information regarding the place of intervention; of these studies, 61% developed their interventions in university facilities. The interventions were mainly based on therapeutic physical exercise (89% of the articles), with a duration of 2-6 months (95% of the articles) and a frequency of 2-3 times a week (95% of the articles) with sessions of 30-60 min (94% of the articles) led by sports science professionals (51% of the articles). The components of physical fitness that were exercised the most were muscular strength (77% of the articles) and cardiorespiratory fitness (47% of the articles). Furthermore, only 48% of the studies included a warm-up stage and 34% of the studies included a cool-down stage.
Conclusions:
This systematic review characterized the physical exercise programs in older adults in Latin America, as well the most frequently used outcome measures and instruments, by summarizing available evidence derived from RCTs. The results will be useful for prescribing future physical exercise programs in older adults.
The purpose of this study was to analyze the effect of a single-set RT program on CVDrisk parameters in untrained older women. Forty-eight older women (> 60 years) were randomly assigned to two groups. The training group (SS) performed a 12-week RT program comprised of single sets (10-15 repetitions) in 8 exercises performed 3 times per week. The control group remained pursued normal daily activities with no exercise intervention. Each participant was evaluated for total cholesterol (TC), high density lipoprotein (HDL), low density lipoprotein (LDL), very low-density lipoprotein (VLDL), triglycerides (TG), glucose (GLU) and, C-reactive protein (CRP). TC, LDL, GLU and CRP were reduced significantly (p< 0.05). We conclude that a 12-week RT program performed with a single-set per exercise is sufficient to reduce cardiovascular diseases risk components.
Objective:
To analyse the effect of resistance training (RT) frequency on muscle mass, appendicular lean soft tissue, insulin-like growth factor 1 (IGF-1), testosterone, and their changes with detraining in older women.
Methods:
Forty-five physically independent older women (≥ 60 years) were randomly assigned to perform RT either two (G2X, n = 21) or three times/week (G3X, n = 24), during 12 weeks (8 exercises, 1 set of 10-15 repetition maximum). Muscle mass and appendicular lean soft tissue, IGF-1, testosterone, and dietary intake were measured at pre-training, post-training, and after detraining (12 weeks).
Results:
Muscle mass and appendicular lean soft tissue significantly increased post-training (G2X = +5.5% and G3X = +5.8%, P < .0001) with no differences between groups, and gains were retained after detraining (G2X = 100% and G3X = 99%, P < .0001). IGF-1 and dietary intake did not change for the groups during the study. Testosterone did not change post-training but significantly decreased after detraining (G2X = -21% and G3X = -50%, P < .0001).
Conclusion:
We conclude that lower RT frequency is as effective as higher frequency to improve muscle mass and appendicular lean soft tissue, and to maintain testosterone and IGF-1. Additionally, detraining may reduce testosterone regardless of RT frequency. These results are specifically for community-dwelling older women and may not be generalized to other populations.
We studied the effects of two different weekly frequency resistance training (RT) protocols over eight weeks on muscle strength and muscle hypertrophy in well-trained men. Twenty-three subjects (age: 26.2±4.2 years; RT experience: 6.9±3.1 years) were randomly allocated into the two groups: low frequency (LFRT, n = 12) or high frequency (HFRT, n = 11). The LFRT performed a split-body routine, training each specific muscle group once a week. The HFRT performed a total-body routine, training all muscle groups every session. Both groups performed the same number of sets (10-15 sets) and exercises (1-2 exercise) per week, 8-12 repetitions maximum (70-80% of 1RM), five times per week. Muscle strength (bench press and squat 1RM) and lean tissue mass (dual-energy x-ray absorptiometry) were assessed prior to and at the end of the study. Results showed that both groups improved (p<0.001) muscle strength [LFRT and HFRT: bench press = 5.6 kg (95% Confidence Interval (CI): 1.9 - 9.4) and 9.7 kg (95%CI: 4.6 - 14.9) and squat = 8.0 kg (95%CI: 2.7 - 13.2) and 12.0 kg (95%CI: 5.1 - 18.1), respectively] and lean tissue mass (p = 0.007) [LFRT and HFRT: total body lean mass = 0.5 kg (95%CI: 0.0 - 1.1) and 0.8 kg (95%CI: 0.0 - 1.6), respectively] with no difference between groups (bench press, p = 0.168; squat, p = 0.312 and total body lean mass, p = 0.619). Thus, HFRT and LFRT are similar overload strategies for promoting muscular adaptation in well-trained subjects when the sets and intensity are equated per week.
The aim of this study was to analyze the effect of two different methods (clustering and multi-sets) on resistance training on heart
rate variability (HRV) in young adults. A total of 31 volunteers were randomly divided into three groups: clustering (GCL), multi-sets
(GMS) and control group (CG). Group and time interaction was identified (F(3, 28) = 36.71, P < 0.01), with reduction in CG (P = 0.01)
and increase in GCL (P = 0.01) and GMS (P = 0.01). It was concluded that both clustering and multi-sets enhanced HRV after 8 weeks
of resistance training in trained young adult males.
It is generally accepted that neural factors play an important role in muscle strength gains. This article reviews the neural adaptations in strength, with the goal of laying the foundations for practical applications in sports medicine and rehabilitation. An increase in muscular strength without noticeable hypertrophy is the first line of evidence for neural involvement in acquisition of muscular strength. The use of surface electromyographic (SEMG) techniques reveal that strength gains in the early phase of a training regimen are associated with an increase in the amplitude of SEMG activity. This has been interpreted as an increase in neural drive, which denotes the magnitude of efferent neural output from the CNS to active muscle fibres. However, SEMG activity is a global measure of muscle activity. Underlying alterations in SEMG activity are changes in motor unit firing patterns as measured by indwelling (wire or needle) electrodes. Some studies have reported a transient increase in motor unit firing rate. Training-related increases in the rate of tension development have also been linked with an increased probability of doublet firing in individual motor units. A doublet is a very short interspike interval in a motor unit train, and usually occurs at the onset of a muscular contraction. Motor unit synchronisation is another possible mechanism for increases in muscle strength, but has yet to be definitely demonstrated. There are several lines of evidence for central control of training-related adaptation to resistive exercise. Mental practice using imagined contractions has been shown to increase the excitability of the cortical areas involved in movement and motion planning. However, training using imagined contractions is unlikely to be as effective as physical training, and it may be more applicable to rehabilitation. Retention of strength gains after dissipation of physiological effects demonstrates a strong practice effect. Bilateral contractions are associated with lower SEMG and strength compared with unilateral contractions of the same muscle group. SEMG magnitude is lower for eccentric contractions than for concentric contractions. However, resistive training can reverse these trends. The last line of evidence presented involves the notion that unilateral resistive exercise of a specific limb will also result in training effects in the unexercised contralateral limb (cross-transfer or cross-education). Peripheral involvement in training-related strength increases is much more uncertain. Changes in the sensory receptors (i.e. Golgi tendon organs) may lead to disinhibition and an increased expression of muscular force. Agonist muscle activity results in limb movement in the desired direction, while antagonist activity opposes that motion. Both decreases and increases in co-activation of the antagonist have been demonstrated. A reduction in antagonist co-activation would allow increased expression of agonist muscle force, while an increase in antagonist co-activation is important for maintaining the integrity of the joint. Thus far, it is not clear what the CNS will optimise: force production or joint integrity. The following recommendations are made by the authors based on the existing literature. Motor learning theory and imagined contractions should be incorporated into strength-training practice. Static contractions at greater muscle lengths will transfer across more joint angles. Submaximal eccentric contractions should be used when there are issues of muscle pain, detraining or limb immobilisation. The reversal of antagonists (antagonist-to-agonist) proprioceptive neuromuscular facilitation contraction pattern would be useful to increase the rate of tension development in older adults, thus serving as an important prophylactic in preventing falls. When evaluating the neural changes induced by strength training using EMG recording, antagonist EMG activity should always be measured and evaluated.
This study investigated the effects of low-and high-volume strength trainings on neuromuscular adaptations of lower-and upper-body muscles in older women after 6 weeks (6WE), 13 weeks (13WE), and 20 weeks (20WE) of training. Healthy older women were assigned to low-volume (LV) or high-volume (HV) training groups. The LV group performed one set of each exercise , while the HV group performed three sets, 2 days/ week. Knee extension and elbow flexion one-repetition maximum (1-RM), maximal isometric strength, maximal muscle activation, and muscle thickness (MT) of the lower-and upper-body muscles, as well as lower-body muscle quality (MQ) obtained by ultrasonography, were evaluated. Knee extension and elbow flexion 1-RM improved at all time points for both groups; however, knee extension 1-RM gains were greater for the HV group after 20WE. Maximal isometric strength of the lower body for both groups increased only at 20WE, while upper-body maximal isometric strength increased after 13WE and 20WE. Maximal activation of the lower and upper body for both groups increased only after 20WE. Both groups showed significant increases in MT of their lower and upper body, with greater gains in lower-body MT for the HV group at 20WE. MQ improved in both groups after 13WE and 20WE, whereas the HV group improved more than the LV group at 20WE. These results showed that low-and high-volume trainings have a similar adaptation time course in the muscular function of upper-body muscles. However, high-volume training appears to be more efficient for lower-body muscles after 20 weeks of training.
This study investigated the effects of low- and high-volume strength trainings on neuromuscular adaptations of lower- and upper-body muscles in older women after 6 weeks (6WE), 13 weeks (13WE), and 20 weeks (20WE) of training. Healthy older women were assigned to low-volume (LV) or high-volume (HV) training groups. The LV group performed one set of each exercise, while the HV group performed three sets, 2 days/week. Knee extension and elbow flexion one-repetition maximum (1-RM), maximal isometric strength, maximal muscle activation, and muscle thickness (MT) of the lower- and upper-body muscles, as well as lower-body muscle quality (MQ) obtained by ultrasonography, were evaluated. Knee extension and elbow flexion 1-RM improved at all time points for both groups; however, knee extension 1-RM gains were greater for the HV group after 20WE. Maximal isometric strength of the lower body for both groups increased only at 20WE, while upper-body maximal isometric strength increased after 13WE and 20WE. Maximal activation of the lower and upper body for both groups increased only after 20WE. Both groups showed significant increases in MT of their lower and upper body, with greater gains in lower-body MT for the HV group at 20WE. MQ improved in both groups after 13WE and 20WE, whereas the HV group improved more than the LV group at 20WE. These results showed that low- and high-volume trainings have a similar adaptation time course in the muscular function of upper-body muscles. However, high-volume training appears to be more efficient for lower-body muscles after 20 weeks of training.
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.
The purpose of this Position Stand is to provide guidance to professionals who counsel and prescribe individualized exercise to apparently healthy adults of all ages. These recommendations also may apply to adults with certain chronic diseases or disabilities, when appropriately evaluated and advised by a health professional. This document supersedes the 1998 American College of Sports Medicine (ACSM) Position Stand, "The Recommended Quantity and Quality of Exercise for Developing and Maintaining Cardiorespiratory and Muscular Fitness, and Flexibility in Healthy Adults." The scientific evidence demonstrating the beneficial effects of exercise is indisputable, and the benefits of exercise far outweigh the risks in most adults. A program of regular exercise that includes cardiorespiratory, resistance, flexibility, and neuromotor exercise training beyond activities of daily living to improve and maintain physical fitness and health is essential for most adults. The ACSM recommends that most adults engage in moderate-intensity cardiorespiratory exercise training for ≥30 min·d on ≥5 d·wk for a total of ≥150 min·wk, vigorous-intensity cardiorespiratory exercise training for ≥20 min·d on ≥3 d·wk (≥75 min·wk), or a combination of moderate- and vigorous-intensity exercise to achieve a total energy expenditure of ≥500-1000 MET·min·wk. On 2-3 d·wk, adults should also perform resistance exercises for each of the major muscle groups, and neuromotor exercise involving balance, agility, and coordination. Crucial to maintaining joint range of movement, completing a series of flexibility exercises for each the major muscle-tendon groups (a total of 60 s per exercise) on ≥2 d·wk is recommended. The exercise program should be modified according to an individual's habitual physical activity, physical function, health status, exercise responses, and stated goals. Adults who are unable or unwilling to meet the exercise targets outlined here still can benefit from engaging in amounts of exercise less than recommended. In addition to exercising regularly, there are health benefits in concurrently reducing total time engaged in sedentary pursuits and also by interspersing frequent, short bouts of standing and physical activity between periods of sedentary activity, even in physically active adults. Behaviorally based exercise interventions, the use of behavior change strategies, supervision by an experienced fitness instructor, and exercise that is pleasant and enjoyable can improve adoption and adherence to prescribed exercise programs. Educating adults about and screening for signs and symptoms of CHD and gradual progression of exercise intensity and volume may reduce the risks of exercise. Consultations with a medical professional and diagnostic exercise testing for CHD are useful when clinically indicated but are not recommended for universal screening to enhance the safety of exercise.
We compared early-phase effects between high- and low-volume moderate-intensity resistance training on lean muscle volume, maximal bilateral leg extension strength, maximal isometric torque, normalized maximal bilateral leg extension strength, normalized maximal isometric torque, and muscle recruitment of the right knee extensors in previously untrained young (23.8 ± 3.7 years, range 20-30 years; n = 16) and older women (67.6 ± 6.3 years, range 60-78 years; n = 15). Participants performed either one set or three sets of 10 repetitions for the bilateral leg extension and bilateral leg curl at an intensity of 50-75% of maximal strength 3 days per week for 10 weeks. Main effects were observed over time for all variables (P < 0.05) with increases ranging from 7.1% to 27.8% and effect sizes (Cohen's d) ranging from 0.45 to 1.38. No interactions between age and training volume over time were observed for any variable (P > 0.05). Our results provide a novel contribution to the literature demonstrating that additional neuromuscular adaptation during early-phase moderate-intensity resistance training in previously untrained young and older women may not be elicited through higher-volume training when training loads are matched provided that a minimal volume threshold is attained. These findings may have practical applications for the prescription of short-duration resistance training programmes to enhance muscle strength and achieve hypertrophic and non-hypertrophic adaptations in untrained women.
To compare the effects of an acute one versus three-set full body resistance training (RT) bout in eight overweight (mean ± SD, BMI = 25.6 ± 1.5 kg m(-2)) young (21.0 ± 1.5 years) adults on resting energy expenditure (REE) measured on four consecutive mornings following each protocol. Participants performed a single one-set or three-set whole body (10 exercises, 10 repetition maximum) RT bout following the American College of Sports Medicine (ACSM) guidelines for RT. REE and respiratory exchange ratio (RER) by indirect calorimetry were measured at baseline and at 24, 48, and 72 h after the RT bout. Participants performed each protocol in randomized, counterbalanced order separated by 7 days. There was no difference between protocols for REE or RER. However, REE was significantly (p < 0.05) elevated (~5% or ~400 kJ day(-1)) in both the protocols at 24, 48, and 72 h post RT bout compared with baseline. There was a no change in RER in both the protocols at 72 h compared to baseline. A one-set RT bout following the ACSM guidelines for RT and requiring only ~15 min to complete was as effective as a three-set RT bout (~35 min to complete) in elevating REE for up to 72 h post RT in overweight college males, a group at high risk of developing obesity. The one-set RT protocol may provide an attractive alternative to either aerobic exercise or multiple-set RT programs for weight management in young adults, due to the minimal time commitment and the elevation in REE post RT bout.
Sarcopenia is the loss of skeletal muscle mass and function with aging. Although the term sarcopenia was first coined in 1989, its etiology is still poorly understood. Moreover, a consensus for defining sarcopenia continues to elude us. Sarcopenic changes in the muscle include losses in muscle fiber quantity and quality, alpha-motor neurons, protein synthesis rates, and anabolic and sex hormone production. Other factors include basal metabolic rate, increased protein dietary requirements, and chronic inflammation secondary to age-related changes in cytokines and oxidative stress. These changes lead to decreased overall physical functioning, increased frailty, falls risk, and ultimately the loss of independent living. Because the intertwining relationships of these factors are complex, effective treatment options are still under investigation. The published data on sarcopenia are vast, and this review is not intended to be exhaustive. The aim of this review is to provide an update on the current knowledge of the definition, etiology, consequences, and current clinical trials that may help address this pressing public health problem for our aging populations.
Previous meta-analyses have compared the effects of single to multiple sets on strength, but analyses on muscle hypertrophy are lacking. The purpose of this study was to use multilevel meta-regression to compare the effects of single and multiple sets per exercise on muscle hypertrophy. The analysis comprised 55 effect sizes (ESs), nested within 19 treatment groups and 8 studies. Multiple sets were associated with a larger ES than a single set (difference = 0.10 +/- 0.04; confidence interval [CI]: 0.02, 0.19; p = 0.016). In a dose-response model, there was a trend for 2-3 sets per exercise to be associated with a greater ES than 1 set (difference = 0.09 +/- 0.05; CI: -0.02, 0.20; p = 0.09), and a trend for 4-6 sets per exercise to be associated with a greater ES than 1 set (difference = 0.20 +/- 0.11; CI: -0.04, 0.43; p = 0.096). Both of these trends were significant when considering permutation test p values (p < 0.01). There was no significant difference between 2-3 sets per exercise and 4-6 sets per exercise (difference = 0.10 +/- 0.10; CI: -0.09, 0.30; p = 0.29). There was a tendency for increasing ESs for an increasing number of sets (0.24 for 1 set, 0.34 for 2-3 sets, and 0.44 for 4-6 sets). Sensitivity analysis revealed no highly influential studies that affected the magnitude of the observed differences, but one study did slightly influence the level of significance and CI width. No evidence of publication bias was observed. In conclusion, multiple sets are associated with 40% greater hypertrophy-related ESs than 1 set, in both trained and untrained subjects.
There has been considerable debate over the optimal number of sets per exercise to improve musculoskeletal strength during a resistance exercise program. The purpose of this study was to use hierarchical, random-effects meta-regression to compare the effects of single and multiple sets per exercise on dynamic strength. English-language studies comparing single with multiple sets per exercise, while controlling for other variables, were considered eligible for inclusion. The analysis comprised 92 effect sizes (ESs) nested within 30 treatment groups and 14 studies. Multiple sets were associated with a larger ES than a single set (difference = 0.26 +/- 0.05; confidence interval [CI]: 0.15, 0.37; p < 0.0001). In a dose-response model, 2 to 3 sets per exercise were associated with a significantly greater ES than 1 set (difference = 0.25 +/- 0.06; CI: 0.14, 0.37; p = 0.0001). There was no significant difference between 1 set per exercise and 4 to 6 sets per exercise (difference = 0.35 +/- 0.25; CI: -0.05, 0.74; p = 0.17) or between 2 to 3 sets per exercise and 4 to 6 sets per exercise (difference = 0.09 +/- 0.20; CI: -0.31, 0.50; p = 0.64). There were no interactions between set volume and training program duration, subject training status, or whether the upper or lower body was trained. Sensitivity analysis revealed no highly influential studies, and no evidence of publication bias was observed. In conclusion, 2 to 3 sets per exercise are associated with 46% greater strength gains than 1 set, in both trained and untrained subjects.
The Health Enhancing Strength Training in Nonagenarians (STRONG) is a randomised control trial to assess the effectiveness of an aerobic and strength training program for improving muscle strength, functional capacity and quality of life in nonagenarians.
Sixty (51 women) nonagenarians (age range: 90-102 years) who live in a geriatric nursing home will be randomly assigned to either a usual care (control) group (n = 30) or an intervention (training) group (n = 30). Participants allocated in the usual care group will receive general physical activity guidelines and participants allocated in the intervention group will also enroll in three weekly non-consecutive individualized training sessions (approximately 45-50 min each) during 8 weeks. The exercise program will consist of muscular strength [with a special focus on leg press at 30% (start of the program) to 70% 1 repetition maximum (end)] and aerobic exercises (cycle-ergometry during 3-5 to 15 minutes at 12-14 points in the rate of perceived exertion scale).
Results from STRONG will help to better understand the potential of regular physical activity for improving the well-being of the oldest population groups.
The increase in life expectancy together with the dramatic decrease in birth rates in industrialized countries calls the attention to health care systems and public health policymakers to focus attention on promoting healthy lifestyle in the highest sector of the population pyramid. Our study attempts to improve functional capacity and QOL of nonagenarians by implementing an individualised aerobic and strength training program in a geriatric residential care. Results from STRONG will help to better understand the potential of regular physical activity for improving the well being even in persons aged 90 years or over.
Muscle dysfunction and associated mobility impairment, common among the frail elderly, increase the risk of falls, fractures, and functional dependency. We sought to characterize the muscle weakness of the very old and its reversibility through strength training. Ten frail, institutionalized volunteers aged 90 ± 1 years undertook 8 weeks of high-intensity resistance training. Initially, quadriceps strength was correlated negatively with walking time (r= -.745). Fat-free mass (r=.732) and regional muscle mass (r=.752) were correlated positively with muscle strength. Strength gains averaged 174% ±31% (mean ± SEM) in the 9 subjects who completed training. Midthigh muscle area increased 9.0%± 4.5%. Mean tandem gait speed improved 48% after training. We conclude that high-resistance weight training leads to significant gains in muscle strength, size, and functional mobility among frail residents of nursing homes up to 96 years of age.
(JAMA. 1990;263:3029-3034)
To determine how multiple risk factors for osteoporotic fractures could be modified by high-intensity strength training exercises in postmenopausal women.
Randomized controlled trial of 1-year duration.
Exercise laboratory at Tufts University, Boston, Mass.
Forty postmenopausal white women, 50 to 70 years of age, participated in the study; 39 women completed the study. The subjects were sedentary and estrogen-deplete.
High-intensity strength training exercises 2 days per week using five different exercises (n = 20) vs untreated controls (n = 19).
Dual energy x-ray absorptiometry for bone status, one repetition maximum for muscle strength, 24-hour urinary creatinine for muscle mass, and backward tandem walk for dynamic balance.
Femoral neck bone mineral density and lumbar spine bone mineral density increased by 0.005 +/- 0.039 g/cm2 (0.9% +/- 4.5%) (mean +/- SD) and 0.009 +/- 0.033 g/cm2 (1.0% +/- 3.6%), respectively, in the strength-trained women and decreased by -0.022 +/- 0.035 g/cm2 (-2.5% +/- 3.8%) and -0.019 +/- 0.035 g/cm2 (-1.8% +/- 3.5%), respectively, in the controls (P = .02 and .04). Total body bone mineral content was preserved in the strength-trained women (+2.0 +/- 68 g; 0.0% +/- 3.0%) and tended to decrease in the controls (-33+77 g; -1.2% +/- 3.4%, P = .12). Muscle mass, muscle strength, and dynamic balance increased in the strength-trained women and decreased in the controls (P = .03 to < .001).
High-intensity strength training exercises are an effective and feasible means to preserve bone density while improving muscle mass, strength, and balance in postmenopausal women.
Body composition and the components of energy metabolism were examined in 12 men and women, aged 56-80 y, before and after 12 wk of resistance training. Subjects were randomly assigned to groups that consumed diets that providing either 0.8 or 1.6 g protein.kg-1.d-1 and adequate total energy to maintain baseline body weight. Fat mass decreased 1.8 +/- 0.4 kg (P < 0.001) and fat-free mass (FFM) increased 1.4 +/- 0.4 kg (P < 0.01) in these weight-stable subjects. The increase in FFM was associated with a 1.6 +/- 0.4 kg increase in total body water (P < 0.01) but no significant change in either protein plus mineral mass or body cell mass. With resistance training, the mean energy intake required for body weight maintenance increased by approximately 15%. Increased energy expenditure included increased resting metabolic rate (P < 0.02) and the energy cost of resistance exercise. Dietary protein intake did not influence these results. Resistance training is an effective way to increase energy requirements, decrease body-fat mass, and maintain metabolically active tissue mass in healthy older people and may be useful as an adjunct to weight-control programs for older adults.
Falls warrant investigation as a risk factor for nursing home admission because falls are common and are associated with functional disability and because they may be preventable.
We conducted a prospective study of a probability sample of 1103 people over 71 years of age who were living in the community. Data on demographic and medical characteristics, use of health care, and cognitive, functional, psychological, and social functioning were obtained at base line and one year later during assessments in the participants' homes. The primary outcome studied was the number of days from the initial assessment to a first long-term admission to a skilled-nursing facility during three years of follow-up. Patients were assigned to four categories during follow-up: those who had no falls, those who had one fall without serious injury, those who had two or more falls without serious injury, and those who had at least one fall causing serious injury.
A total of 133 participants (12.1 percent) had long-term admissions to nursing homes. In an unadjusted model, the risk of admission increased progressively, as compared with that for the patients with no falls, for those with a single noninjurious fall (relative risk, 4.9; 95 percent confidence interval, 3.2 to 7.5), those with multiple noninjurious falls (relative risk, 8.5; 95 percent confidence interval, 3.4 to 21.2), and those with at least one fall causing serious injury (relative risk, 19.9; 95 percent confidence interval, 12.2 to 32.6). Adjustment for other risk factors lowered these ratios to 3.1 (95 percent confidence interval, 1.9 to 4.9) for one noninjurious fall, 5.5 (95 percent confidence interval, 2.1 to 14.2) for two or more noninjurious falls, and 10.2 (95 percent confidence interval, 5.8 to 17.9) for at least one fall causing serious injury, but the association between falls and admission to a nursing home remained strong and significant. The population attributable risk of long-term admission to a nursing home for these three groups (the proportion of admissions directly attributable to the three categories of falls) was 13 percent, 3 percent, and 10 percent, respectively.
Among older people living in the community falls are a strong predictor of placement in a skilled-nursing facility; interventions that prevent falls and their sequelae may therefore delay or reduce the frequency of nursing home admissions.
To establish the prevalence of sarcopenia in older Americans and to test the hypothesis that sarcopenia is related to functional impairment and physical disability in older persons.
Cross-sectional survey.
Nationally representative cross-sectional survey using data from the Third National Health and Nutrition Examination Survey (NHANES III).
Fourteen thousand eight hundred eighteen adult NHANES III participants aged 18 and older.
The presence of sarcopenia and the relationship between sarcopenia and functional impairment and disability were examined in 4,504 adults aged 60 and older. Skeletal muscle mass was estimated from bioimpedance analysis measurements and expressed as skeletal muscle mass index (SMI = skeletal muscle mass/body mass x 100). Subjects were considered to have a normal SMI if their SMI was greater than -one standard deviation above the sex-specific mean for young adults (aged 18-39). Class I sarcopenia was considered present in subjects whose SMI was within -one to -two standard deviations of young adult values, and class II sarcopenia was present in subjects whose SMI was below -two standard deviations of young adult values.
The prevalence of class I and class II sarcopenia increased from the third to sixth decades but remained relatively constant thereafter. The prevalence of class I (59% vs 45%) and class II (10% vs 7%) sarcopenia was greater in the older (> or = 60 years) women than in the older men (P <.001). The likelihood of functional impairment and disability was approximately two times greater in the older men and three times greater in the older women with class II sarcopenia than in the older men and women with a normal SMI, respectively. Some of the associations between class II sarcopenia and functional impairment remained significant after adjustment for age, race, body mass index, health behaviors, and comorbidity.
Reduced relative skeletal muscle mass in older Americans is a common occurrence that is significantly and independently associated with functional impairment and disability, particularly in older women. These observations provide strong support for the prevailing view that sarcopenia may be an important and potentially reversible cause of morbidity and mortality in older persons.
To estimate the healthcare costs of sarcopenia in the United States and to examine the effect that a reduced sarcopenia prevalence would have on healthcare expenditures.
Cross-sectional surveys.
Nationally representative surveys using data from the U.S. Census, Third National Health and Nutrition Examination Survey, and National Medical Care and Utilization Expenditure Survey.
Representative samples of U.S. adults aged 60 and older.
The healthcare costs of sarcopenia were estimated based on the effect of sarcopenia on increasing physical disability risk in older persons. In the first step, the healthcare cost of disability in older Americans was estimated from national surveys. In the second step, the proportion of the disability cost due to sarcopenia (population-attributable risk) was calculated to determine the healthcare costs of sarcopenia. These calculations relied upon previously published relative risk values for disability in sarcopenic individuals and sarcopenia prevalence rates in the older population.
The estimated direct healthcare cost attributable to sarcopenia in the United States in 2000 was $18.5 billion ($10.8 billion in men, $7.7 billion in women), which represented about 1.5% of total healthcare expenditures for that year. A sensitivity analysis indicated that the costs could be as low as $11.8 billion and as high as $26.2 billion. The excess healthcare expenditures were $860 for every sarcopenic man and $933 for every sarcopenic woman. A 10% reduction in sarcopenia prevalence would result in savings of $1.1 billion (dollars adjusted to 2000 rate) per year in U.S. healthcare costs.
Sarcopenia imposes a significant but modifiable economic burden on government-reimbursed healthcare services in the United States. Because the number of older Americans is increasing, the economic costs of sarcopenia will escalate unless effective public health campaigns aimed at reducing the occurrence of sarcopenia are implemented.
The efficiency, safety, and effectiveness of strength training programs are paramount for sport conditioning. Therefore, identifying optimal doses of the training variables allows for maximal gains in muscular strength to be elicited per unit of time and also for the reduction in risk of overtraining and/or overuse injuries. A quantified dose-response relationship for the continuum of training intensities, frequencies, and volumes has been identified for recreationally trained populations but has yet to be identified for competitive athletes. The purpose of this analysis was to identify this relationship in collegiate, professional, and elite athletes. A meta-analysis of 37 studies with a total of 370 effect sizes was performed to identify the dose-response relationship among competitive athletes. Criteria for study inclusion were (a) participants must have been competitive athletes at the collegiate or professional level, (b) the study must have employed a strength training intervention, and (c) the study must have included necessary data to calculate effect sizes. Effect size data demonstrate that maximal strength gains are elicited among athletes who train at a mean training intensity of 85% of 1 repetition maximum (1RM), 2 days per week, and with a mean training volume of 8 sets per muscle group. The current data exhibit different dose-response trends than previous meta-analytical investigations with trained and untrained nonathletes. These results demonstrate explicit dose-response trends for maximal strength gains in athletes and may be directly used in strength and conditioning venues to optimize training efficiency and effectiveness.
It is generally accepted that neural factors play an important role in muscle strength gains. This article reviews the neural adaptations in strength, with the goal of laying the foundations for practical applications in sports medicine and rehabilitation. An increase in muscular strength without noticeable hypertrophy is the first line of evidence for neural involvement in acquisition of muscular strength. The use of surface electromyographic (SEMG) techniques reveal that strength gains in the early phase of a training regimen are associated with an increase in the amplitude of SEMG activity. This has been interpreted as an increase in neural drive, which denotes the magnitude of efferent neural output from the CNS to active muscle fibres. However, SEMG activity is a global measure of muscle activity. Underlying alterations in SEMG activity are changes in motor unit firing patterns as measured by indwelling (wire or needle) electrodes. Some studies have reported a transient increase in motor unit firing rate. Training-related increases in the rate of tension development have also been linked with an increased probability of doublet firing in individual motor units. A doublet is a very short interspike interval in a motor unit train, and usually occurs at the onset of a muscular contraction. Motor unit synchronisation is another possible mechanism for increases in muscle strength, but has yet to be definitely demonstrated. There are several lines of evidence for central control of training-related adaptation to resistive exercise. Mental practice using imagined contractions has been shown to increase the excitability of the cortical areas involved in movement and motion planning. However, training using imagined contractions is unlikely to be as effective as physical training, and it may be more applicable to rehabilitation. Retention of strength gains after dissipation of physiological effects demonstrates a strong practice effect. Bilateral contractions are associated with lower SEMG and strength compared with unilateral contractions of the same muscle group. SEMG magnitude is lower for eccentric contractions than for concentric contractions. However, resistive training can reverse these trends. The last line of evidence presented involves the notion that unilateral resistive exercise of a specific limb will also result in training effects in the unexercised contralateral limb (cross-transfer or cross-education). Peripheral involvement in training-related strength increases is much more uncertain. Changes in the sensory receptors (i.e. Golgi tendon organs) may lead to disinhibition and an increased expression of muscular force. Agonist muscle activity results in limb movement in the desired direction, while antagonist activity opposes that motion. Both decreases and increases in co-activation of the antagonist have been demonstrated. A reduction in antagonist co-activation would allow increased expression of agonist muscle force, while an increase in antagonist co-activation is important for maintaining the integrity of the joint. Thus far, it is not clear what the CNS will optimise: force production or joint integrity. The following recommendations are made by the authors based on the existing literature. Motor learning theory and imagined contractions should be incorporated into strength-training practice. Static contractions at greater muscle lengths will transfer across more joint angles. Submaximal eccentric contractions should be used when there are issues of muscle pain, detraining or limb immobilisation. The reversal of antagonists (antagonist-to-agonist) proprioceptive neuromuscular facilitation contraction pattern would be useful to increase the rate of tension development in older adults, thus serving as an important prophylactic in preventing falls. When evaluating the neural changes induced by strength training using EMG recording, antagonist EMG activity should always be measured and evaluated.
Aging is associated with declines in the neuromuscular and cardiovascular systems, resulting in an impaired capacity to perform daily activities. Frailty is an age-associated biological syndrome characterized by decreases in the biological functional reserve and resistance to stressors due to changes in several physiological systems, which puts older individuals at special risk of disability. To counteract the neuromuscular and cardiovascular declines associated with aging, as well as to prevent and treat the frailty syndrome, the strength and endurance training seems to be an effective strategy to improve muscle hypertrophy, strength and power output, as well as endurance performance. The first purpose of this review was discuss the neuromuscular adaptations to strength training, as well as the cardiovascular adaptations to endurance training in healthy and frail elderly subjects. In addition, the second purpose of this study was investigate the concurrent training adaptations in the elderly. Based on the results found, the combination of strength and endurance training (i.e., concurrent training) performed at moderate volume and moderate to high intensity in elderly populations is the most effective way to improve both neuromuscular and cardiorespiratory functions. Moreover, exercise interventions that include muscle power training should be prescribed to frail elderly in order to improve the overall physical status of this population and prevent disability.
SUMMARY In order to stimulate further adaptation toward specific training goals, progressive resistance training (RT) protocols are necessary. The optimal characteristics of strength-specific programs include the use of concentric (CON), eccentric (ECC), and isometric muscle actions and the performance of bilateral and unilateral single- and multiple-joint exercises. In addition, it is recommended that strength programs sequence exercises to optimize the preservation of exercise intensity (large before small muscle group exercises, multiple-joint exercises before single-joint exercises, and higher-intensity before lower-intensity exercises). For novice (untrained individuals with no RT experience or who have not trained for several years) training, it is recommended that loads correspond to a repetition range of an 8-12 repetition maximum (RM). For intermediate (individuals with approximately 6 months of consistent RT experience) to advanced (individuals with years of RT experience) training, it is recommended that individuals use a wider loading range from 1 to 12 RM in a periodized fashion with eventual emphasis on heavy loading (1-6 RM) using 3- to 5-min rest periods between sets performed at a moderate contraction velocity (1-2 s CON; 1-2 s ECC). When training at a specific RM load, it is recommended that 2-10% increase in load be applied when the individual can perform the current workload for one to two repetitions over the desired number. The recommendation for training frequency is 2-3 dIwkj1 for novice training, 3-4 dIwkj1 for intermediate training, and 4-5 dIwkj1 for advanced training. Similar program designs are recom- mended for hypertrophy training with respect to exercise selection and frequency. For loading, it is recommended that loads corresponding to 1-12 RM be used in periodized fashion with emphasis on the 6-12 RM zone using 1- to 2-min rest periods between sets at a moderate velocity. Higher volume, multiple-set programs are recommended for maximizing hypertrophy. Progression in power training entails two general loading strategies: 1) strength training and 2) use of light loads (0-60% of 1 RM for lower body exercises; 30-60% of 1 RM for upper body exercises) performed at a fast contraction velocity with 3-5 min of rest between sets for multiple sets per exercise (three to five sets). It is also recommended that emphasis be placed on multiple-joint exercises especially those involving the total body. For local muscular endurance training, it is recommended that light to moderate loads (40-60% of 1 RM) be performed for high repetitions (915) using short rest periods (G90 s). In the interpretation of this position stand as with prior ones, recommendations should be applied in context and should be contingent upon an individual's target goals, physical capacity, and training
Strength is a fundamental component of physical fitness, and therefore should be precisely assessed. The purpose of this study was to analyze the number of testing sessions required to achieve consistent 1 repetition maximum (1RM) strength measurements in untrained older women. Forty-five untrained older women were measured for 1RM in bench press machine (BP), leg extension machine (LE), and free weight arm curl (AC). Reliability coefficients for trials 1 and 2 for BP (ICC = 0.973) and LE (ICC = 0.976) were higher than for AC (ICC = 0.953). Percent change from trial 1 to 2 for BP (3.5 ± 10.9%) and AC (3.8 ± 8.1%) was less than for LE (5.4 ± 6.2%), but all were significant increases between trials (p < 0.05). Trial differences were reduced to nonsignificant levels (p > 0.05) in the 3rd trial for BP (0.0 ± 0.0%), LE (1.2 ± 3.0%) and AC (2.7 ± 5.9%). Reliability coefficients rose for BP and LE (ICC = 0.999) and AC (ICC = 0.963) when a 3rd trial was performed. Bland and Altman plotting showed very small bias and limits of agreement for both the exercises (BP: bias = 0 kg, LoA = 0 kg; LE: bias = -0.16 kg, LoA = 2.21 kg; AC: bias = -0.11 kg, LoA = 1.72 kg). This approach for determine 1RM strength values produced rapid lifting technique familiarization, resulting in a need of 2 to 3 test sessions to achieve consistent 1RM measurements in untrained older women.
This study investigated changes in body composition in women over 30 (n = 68) after a 12-wk weight training program. A control group (n = 27) was used for comparison of body composition measures only. The experimental group performed 13 exercises 3 days a week for 12 weeks. Initially there were no significant differences in gross body weight, % body fat, FFW, and sum of skinfolds between groups. The experimental group reduced their % body fat and sum of skinfolds while increasing their FFW. There were no significant changes in the controls. To determine the influence of age, the experimental group was subdivided into those under 40 (UF) and those over 40 (OF). Although there were no significant differences in gross body weight between UF and OF at pre or posttests, the UF had significantly lower % body fat and skinfold sums and higher FFW than the OF. As a result of the weight training program, neither age group's gross body weight changed significantly, but both groups significantly decreased their % body fat and increased FFW.
(C) 1994 National Strength and Conditioning Association
Resting metabolic rate (RMR) decreases with age, largely because of an age-related decline in fat-free mass (FFM). We hypothesized that a strength-training program capable of eliciting increases in FFM would also increase RMR in older individuals. To test this hypothesis, RMR, body composition, and plasma concentrations of certain hormones known to affect RMR were measured before and after a 16-wk heavy-resistance strength-training program in 13 healthy men 50-65 yr of age. Average strength levels, assessed by the three-repetition maximum test, increased 40% with training (P < 0.001). Body weight did not change, but body fat decreased (25.6 +/- 1.5 vs. 23.7 +/- 1.7%; P < 0.001) and FFM increased (60.6 +/- 2.2 vs. 62.2 +/- 2.1 kg; P < 0.01). RMR, measured by indirect calorimetry, increased 7.7% with strength training (6,449 +/- 217 vs. 6,998 +/- 226 kJ/24 h; P < 0.01). This increase remained significant even when RMR was expressed per kilogram of FFM. Strength training increased arterialized plasma norepinephrine levels 36% (1.1 +/- 0.1 vs. 1.5 +/- 0.1 nmol/l; P < 0.01) but did not change fasting glucose, insulin, or thyroid hormone levels. These results indicate that a heavy-resistance strength-training program increases RMR in healthy older men, perhaps by increasing FFM and sympathetic nervous system activity.
Understanding determinants of initiation and maintenance of an active lifestyle among older individuals is of great concern to public health because of the increasing evidence that lifestyle may alter the course of frequently occurring chronic diseases.
Two thousand five hundred seven community-dwelling Medicare beneficiaries age 65 and over were interviewed at three points over 4 years regarding their physical activity, defined as a self-report of walking briskly, gardening, or heavy housework at least three times a week. Extensive data were also collected on health status, health services use, sociodemographics, and, at the final interview, self-mastery, importance of various factors in the decision to be physically active, and interaction with their physician regarding physical activity. Determinants of initiation and maintenance of physical activity were identified using logistic regressions.
Forty-one percent maintained an active lifestyle; 12% initiated an active lifestyle; 22% declined to become sedentary; 25% were sedentary at all observation. Predictors of both initiation and maintenance of physical activity were younger age, moderate to excellent health, and the patient's belief that physical activity was important to his/her health. Among the 301 patients who initiated activity, 40% said their physician was a very important influence.
Strengthening the belief of older individuals in the benefits to their health of physical activity holds promise for increasing the proportion of community-dwelling older persons who move from a sedentary lifestyle to a more physically active lifestyle and for maintaining such activity.
The purpose of this study was to determine what effects 26 wk of resistance training have on resting energy expenditure (REE), total free-living energy expenditure (TEE), activity-related energy expenditure (AEE), engagement in free-living physical activity as measured by the activity-related time equivalent (ARTE) index, and respiratory exchange ratio (RER) in 61- to 77-yr-old men (n = 8) and women (n = 7). Before and after training, body composition (four-compartment model), strength, REE, TEE (doubly labeled water), AEE (TEE - REE + thermic response to meals), and ARTE (AEE adjusted for energy cost of standard activities) were evaluated. Strength (36%) and fat-free mass (2 kg) significantly increased, but body weight did not change. REE increased 6.8%, whereas resting RER decreased from 0.86 to 0.83. TEE (12%) and ARTE (38%) increased significantly, and AEE (30%) approached significance (P = 0.06). The TEE increase remained significant even after adjustment for the energy expenditure of the resistance training. In response to resistance training, TEE increased and RER decreased. The increase in TEE occurred as a result of increases in both REE and physical activity. These results suggest that resistance training may have value in increasing energy expenditure and lipid oxidation rates in older adults, thereby improving their metabolic profiles.
The purpose of this study was to compare the number of testing sessions required to achieve consistent 1 repetition maximum (1RM) strength measurements in untrained old and young women. Consistency of measurement was defined as consecutive 1 RM strength measures that increased by 1 kg or less. Untrained old (n = 6, age 66 +/- 5 years) and untrained young (n = 7, age 23 +/- 4 years) women were repeatedly strength-tested for bilateral concentric knee extension 1 RM strength until consecutive measurements were increased by no more than 1 kg. At least 48 hours of rest was allowed between 1 RM measurements. The old subjects required significantly more testing sessions (8-9 sessions) compared with the young subjects (3-4 sessions) to achieve the same absolute consistency of measurement (p < 0.05). Absolute increase in strength between the first and final testing sessions did not differ between groups (young = 11 +/- 4 kg and old = 13 +/- 2 kg) (p > 0.05). The relative increase was significantly greater in the older subjects (young = 12 +/- 5%; old = 22 +/- 4%) (p < 0.05). In conclusion, older subjects require more practice and familiarization and show greater relative increases in 1RM strength when compared with younger subjects of the same experience level. This is important to consider, especially when evaluating the magnitude of strength increase in response to resistance training.
The identification of a quantifiable dose-response relationship for strength training is important to the prescription of proper training programs. Although much research has been performed examining strength increases with training, taken individually, they provide little insight into the magnitude of strength gains along the continuum of training intensities, frequencies, and volumes. A meta-analysis of 140 studies with a total of 1433 effect sizes (ES) was carried out to identify the dose-response relationship.
Studies employing a strength-training intervention and containing data necessary to calculate ES were included in the analysis.
ES demonstrated different responses based on the training status of the participants. Training with a mean intensity of 60% of one repetition maximum elicits maximal gains in untrained individuals, whereas 80% is most effective in those who are trained. Untrained participants experience maximal gains by training each muscle group 3 d.wk and trained individuals 2 d.wk. Four sets per muscle group elicited maximal gains in both trained and untrained individuals.
The dose-response trends identified in this analysis support the theory of progression in resistance program design and can be useful in the development of training programs designed to optimize the effort to benefit ratio.
The loss of muscle mass during aging has been termed sarcopenia. Sarcopenia results in a decrease in physical strength during aging that results in important consequences for more severely affected individuals in terms of function and as a marker for disability and increased mortality. Despite the clinical importance of this condition, the pathophysiology leading to the development of sarcopenia is not well understood, and few treatments exist to prevent or reverse the condition. Recently, sarcopenia has been found to occur during aging in the nematode Caenorhabditis elegans, which is an organism increasingly used to study genetic and biochemical events involved in aging. Like in humans, sarcopenia in C. elegans leads to declines in mobility and serves as a marker for increased mortality. Interestingly, mutations affecting the age-1 gene, which slows aging of the animal, result in significant delays in the development of sarcopenia, suggesting a direct causal relationship between organismal aging and sarcopenia. These findings suggest that, in humans and worms, sarcopenia may represent a biomarker for the biological age, as opposed to chronological age, of the individual. These findings also suggest that C. elegans will develop into an important model system in which to study the biochemical and genetics events responsible for sarcopenia and to test therapeutics designed to prevent or reverse sarcopenia.
To determine whether variation in resistance exercise volume affects muscle function and physical performance response in older adults.
A randomized trial with subjects assigned to a single-set (1-SET) or three-set (3-SET) exercise group.
An exercise facility at the University of Queensland.
Twenty-eight community-dwelling men and women aged 65 to 78.
Progressive resistance training consisting of seven exercises targeting the major muscle groups of the upper and lower body performed on exercise machines twice weekly for 20 weeks at eight-repetition maximum (RM) intensity.
Muscle function included isotonic muscle strength (1-RM) of the seven exercises, isokinetic and isometric knee extensor strength, and muscle endurance for the chest press and leg press exercises. Physical performance included timed chair rise, usual and fast 6-m walk, 6-m backwards walk, 400-m walk, floor rise to standing, and stair climbing ability. In addition, body composition was determined using dual energy x-ray absorptiometry.
Isotonic muscle strength increased in both exercise groups for all seven exercises (P<.01), with the gain in the 3-SET group greater (P<.05) for the seated row, triceps extension, and knee extension (analysis of covariance). Similarly, muscle endurance gains were greater for the 3-SET than the 1-SET group (P<.01), with no significant difference between groups for isokinetic and isometric knee extensor strength. Both groups improved (P<.05) in the chair rise (1-SET, 10.1%; 3-SET, 13.6%), 6-m backwards walk (1-SET, 14.3%; 3-SET, 14.8%), 400-m walk (1-SET, 3.8%; 3-SET, 7.4%), and stair climbing test (1-SET, 7.7%; 3-SET, 6.4%), with the only difference between groups for the 400-m walk (P<.05). There was no difference between groups for change in body composition.
Resistance training consisting of only single-set exercises is sufficient to significantly enhance muscle function and physical performance, although muscle strength and endurance gains are greater with higher-volume work. These findings have application in designing time-efficient exercise regimens to enhance neuromuscular function in older adults.
Resistance training (RT) has shown the most promise in reducing/reversing effects of sarcopenia, although the optimum regime specific for older adults remains unclear. We hypothesized myofiber hypertrophy resulting from frequent (3 days/wk, 16 wk) RT would be impaired in older (O; 60-75 yr; 12 women, 13 men), sarcopenic adults compared with young (Y; 20-35 yr; 11 women, 13 men) due to slowed repair/regeneration processes. Myofiber-type distribution and cross-sectional area (CSA) were determined at 0 and 16 wk. Transcript and protein levels of myogenic regulatory factors (MRFs) were assessed as markers of regeneration at 0 and 24 h postexercise, and after 16 wk. Only Y increased type I CSA 18% (P < 0.001). O showed smaller type IIa (-16%) and type IIx (-24%) myofibers before training (P < 0.05), with differences most notable in women. Both age groups increased type IIa (O, 16%; Y, 25%) and mean type II (O, 23%; Y, 32%) size (P < 0.05). Growth was generally most favorable in young men. Percent change scores on fiber size revealed an age x gender interaction for type I fibers (P < 0.05) as growth among Y (25%) exceeded that of O (4%) men. Myogenin and myogenic differentiation factor D (MyoD) mRNAs increased (P < 0.05) in Y and O, whereas myogenic factor (myf)-5 mRNA increased in Y only (P < 0.05). Myf-6 protein increased (P < 0.05) in both Y and O. The results generally support our hypothesis as 3 days/wk training led to more robust hypertrophy in Y vs. O, particularly among men. However, this differential hypertrophy adaptation was not explained by age variation in MRF expression.