RESUMO
We compared the magnitude of strength and muscle mass changes in response to resistance training (RT) between stronger older women and their weaker counterparts. Older women (n = 207) were grouped into tertiles according to their baseline muscular strength index. The upper and lower tertiles participants were categorized as stronger (STR, n = 69) and weaker (WKR, n = 69), respectively. Both groups engaged in a 12-week whole-body RT program. Outcomes included one-repetition maximum (1RM) tests in the three lifts and assessment of segmental lean soft tissue (LST) and skeletal muscle mass (SMM). The 1RM increase was similar between groups for the chest press [between-groups effect size of the differences (ESdiff) and 95% confidence interval (95%CI) = 0.10 (95%CI: -0.52, 0.31), P = 0.617] and preacher curl [ESdiff = 0.08 (95%CI: -0.48, 0.32), P = 0.681]. Changes were greater in WKR than STR for 1RM leg extension [ESdiff = -0.45 (95%CI: -0.86, -0.04), P = 0.030]. The increases of segmental LST and SMM were similar between-groups (ESdiff contains zero, P ≥ 0.434). We conclude that stronger and weaker older women benefit similarly for muscle mass and upper-limb strength gains. Notably, weaker older women may experience greater lower-limbs strength gains.
Assuntos
Músculo Esquelético , Treinamento Resistido , Humanos , Feminino , Idoso , Músculo Esquelético/fisiologia , Força Muscular/fisiologiaRESUMO
To date, no meta-analytical study evaluating the benefits of resistance exercise intervention on muscular strength and power and functional capacity in acute hospitalized older adults was conducted. Then, to synthesize the emerging evidence on the effects of resistance exercise intervention on muscular strength and power and functional capacity in acute hospitalized older adults, two independent authors performed a systematic search (PubMed, Scopus, Web of Science, and SciELO) until January 2021. Randomized clinical trials were included regarding the effects of resistance exercise and hospital usual care. The Cochrane Collaboration assessment tool was used to analyze the risk of bias. The comparisons included muscular strength (isometric handgrip strength and one-repetition maximum test of leg press), muscular power (output during leg press exercise), and functional capacity (timed-up-and-go, and short physical performance battery). Resistance exercise intervention increased muscular strength (isometric handgrip strength: mean difference = 2.50 kg, 95% confidence interval (CI) = 1.33, 3.67; and one-repetition maximum test of leg press: mean difference = 19.28 kg, 95% confidence interval = 14.70, 23.86) and muscular power (mean difference = 29.52 W, 95% confidence interval = 28.84, 30.21), and functional capacity (timed-up-and-go: mean difference = 3.40 s, 95% confidence interval = 0.47, 6.36; and short physical performance battery: mean difference = 1.29 points, 95% confidence interval = 0.10, 2.48) at discharge compared with hospital usual care. This meta-analysis endorses the increase of muscular strength and power gains and improving the functional capacity in favor of resistance exercise intervention in acute hospitalized older adults. TRIAL REGISTRATION : https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020203658.
Assuntos
Força da Mão , Força Muscular , Idoso , Exercício Físico , Terapia por Exercício , Humanos , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
The study aimed to compare the effect of performing the same or different exercises for a muscle group on resistance training (RT) sessions on muscle hypertrophy at different sites along muscle length. Twenty-two detrained men (23.3±4.1 years) were randomly allocated to the following groups: a group that performed the same exercises in all training sessions (N-VAR=11) or one that varied the exercises for the same muscle groups (VAR=11). All were submitted to 3 weekly sessions for nine weeks. Muscle thickness was assessed at the proximal, middle, and distal sites of the lateral and anterior thigh, elbow flexors, and extensors by B-mode ultrasound. The VAR group significantly increased all the sites analyzed (P<0.05). Furthermore, the proximal site of the lateral thigh showed a larger relative increase when compared to the middle site (P<0.05). In contrast, the N-VAR group were not revealed significant improvements only for the middle site of the lateral thigh and the proximal site of the elbow flexors (P>0.05). Our results suggest that to perform different resistance exercises can induce hypertrophy of all sites assessed in detrained young men.
Assuntos
Força Muscular , Músculo Esquelético/crescimento & desenvolvimento , Treinamento Resistido/métodos , Adaptação Fisiológica , Adulto , Cotovelo/fisiologia , Humanos , Masculino , Coxa da Perna/fisiologia , Ultrassonografia , Adulto JovemRESUMO
Nunes, JP, Costa, BDV, Kassiano, W, Kunevaliki, G, Castro-e-Souza, P, Rodacki, ALF, Fortes, LS, and Cyrino, ES. Different foot positioning during calf training to induce portion-specific gastrocnemius muscle hypertrophy. J Strength Cond Res 34(8): 2347-2351, 2020-The aim of this study was to compare the changes in gastrocnemius muscle thickness (MT) between conditions such as which foot was pointed outward (FPO), foot was pointed inward (FPI), or foot was pointed forward (FPF). Twenty-two young men (23 ± 4 years) were selected and performed a whole-body resistance training program 3 times per week for 9 weeks, with differences in the exercise specific for calves. The calf-raise exercise was performed unilaterally, in a pin-loaded seated horizontal leg-press machine, in 3 sets of 20-25 repetitions for training weeks 1-3 and 4 sets for weeks 4-9. Each subject's leg was randomly assigned for 1 of the 3 groups according to the foot position: FPO, FPI, and FPF. Measurements with a B-mode ultrasound were performed to assess changes in MT of medial and lateral gastrocnemius heads. After the training period, there were observed increases in MT of both medial (FPO = 8.4%, FPI = 3.8%, and FPF = 5.8%) and lateral (FPO = 5.5%, FPI = 9.1%, and FPF = 6.4%) gastrocnemius heads, and significant differences for magnitude of the gains were observed between FPO and FPI conditions (p < 0.05). Positioning FPO potentiated the increases in MT of the medial gastrocnemius head, whereas FPI provided greater gains for the lateral gastrocnemius head. Our results suggest that head-specific muscle hypertrophy may be obtained selectively for gastrocnemius after 9 weeks of calf training in young male adults.