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CONTEXT: The Hip Stability Isometric Test (HipSIT) is commonly employed in clinical settings for evaluating the hip posterolateral muscle strength. In this study, we introduced the "Field Hip Stability Isometric Test" (F-HipSIT) and assessed the intrarater and interrater reliability of this strength assessment specifically designed for sports settings. DESIGN: Reliability study. METHODS: Two independent raters (A and B) went to athletes' training facilities to conduct 2 sessions of F-HipSIT spaced at least 1 week apart. The average peak force value from 3 valid attempts of each leg was recorded and normalized by the participant's body mass for statistical analysis. RESULTS: Thirty male and 30 female amateur athletes took part in this study. Rater A obtained similar values in the first (0.39 [0.05] and 0.44 [0.07] kg·f/kg) and second (0.39 [0.06] and 0.45 [0.07] kg·f/kg) testing days for men and women, respectively. Rater B also found similar values in the first (0.35 [0.06] and 0.42 [0.08] kg·f/kg) and second (0.36 [0.06] and 0.45 [0.08] kg·f/kg) testing days for men and women, respectively. Excellent intrarater intraclass correlation coefficient (ICC) values were found for men (ICC = .922) and women (ICC = .930), with coefficient of variation of 6% to 8% and minimal detectable change of 0.06 to 0.10 kg·f/kg. The F-HipSIT presented good interrater reliability for men (ICC = .857) and women (ICC = .868), with coefficient of variation of 5% and minimal detectable change of 0.05 to 0.06 kg·f/kg. CONCLUSION: The F-HipSIT intrarater and interrater reliability among male and female recreational athletes supports this field test as a quick and convenient screening tool to monitor hip posterolateral muscle strength in sports settings.
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Teste de Esforço , Contração Isométrica , Força Muscular , Humanos , Masculino , Feminino , Reprodutibilidade dos Testes , Força Muscular/fisiologia , Contração Isométrica/fisiologia , Adulto Jovem , Teste de Esforço/métodos , Teste de Esforço/normas , Adulto , Quadril/fisiologia , Atletas , Músculo Esquelético/fisiologia , Variações Dependentes do Observador , Esportes/fisiologiaRESUMO
The aim of this study was to analyse the load-velocity and load-power relationships in the free-weight back-squat (BSQ) and hexagonal bar deadlift (HBD) exercises. Twenty-five (n = 25) resistance-trained men (age = 23.7 ± 2.8 years) performed a progressive load test at maximal intended velocity to determine their BSQ and HBD one-repetition maximum (1RM). Mean propulsive velocity (MPV) during the concentric phase of the lift was recorded through a linear encoder. Load-velocity and load-power relationships were analysed by fitting linear regression and the second-order polynomial, respectively, to the data. Maximum strength (1RM), MPV (30-80% 1RM), and power output (30-90% 1RM) were higher for HBD compared to BSQ exercise (p < 0.05). A very strong relationship between MPV and relative intensity was found for both BSQ (R2 = 0.963) and HBD (R2 = 0.967) exercises. The load that maximizes power output (Pmax) was 64.6 ± 2.9% (BSQ) and 59.6 ± 1.1% (HBD) 1RM. There was a range of loads at which power output was not different than Pmax (BSQ: 40-80% 1RM; HBD: 50-70% 1RM). In conclusion, the load-velocity and load-power relationships might assist strength and conditioning coaches to monitor and prescribe exercise intensity in the BSQ and HBD exercises using the velocity-based training approach.
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BACKGROUND: The use of predictive equation of muscular torque can reduce physical effort and time spent during evaluation. OBJECTIVES: To establish, validate, and test the accuracy of a prediction equation to estimate the hip external rotators (HER) torque in adults and older adults by means of hip extensors (HEX) torque measurement. METHODS: Eighty-three healthy adults (development set) were assessed to test the association of HEX and HER torques and to establish the prediction equation. A separate 36 adults and 15 older adults (validation sets) were assessed to test the ability of the equation to estimate HER torque. Hip isometric strength was assessed by a handheld dynamometer. RESULTS: Simple linear regression analysis revealed that HEX torque was associated with HER torque (r=0.80; p<0.0001), resulting in the following prediction equation: HERtorque=-0.02+(0.58 * HEXtorque). Paired t-test revealed no difference between directly measured and predicted values of HER torque in adults (mean difference=0.02; 95% CI=-0.115, 0.072) and older adults (mean difference=0.05; 95% CI=-0.02, 0.12). CONCLUSION: The HEX and HER torques were strongly correlated. The prediction equation was valid, accurate, and can be used to estimate HER muscle strength in healthy adults and older adults, requiring only the direct measurement of HEX torque.
Assuntos
Força Muscular/fisiologia , Músculo Esquelético/fisiologia , Quadril/fisiologia , Humanos , Rotação , TorqueRESUMO
BACKGROUND: This study aimed to determine the reliability of the velocity achieved during the last repetition of sets to failure (V last) and the association of V last with the velocity of the 1-repetition maximum (V 1RM) during the paused and touch-and-go bench press (BP) exercises performed in a Smith machine. METHODS: A total of 96 healthy men participated in this study that consisted of two testing sessions. A single BP variant (paused BP or touch-and-go BP) was evaluated on each session in a randomized order. Each session consisted of an incremental loading test until reaching the 1RM, followed by two sets of repetitions to failure against a load ranging from 75% to 90% of 1RM. RESULTS: The reliability of V last was unacceptable for both BP variants (CV > 18.3%, ICC < 0.60). The correlations between V 1RM and V last were small for the paused BP (r = 0.18) and moderate for the touch-and-go BP (r = 0.37). CONCLUSIONS: Although these results suggest that V last could be a better indicator of the minimal velocity threshold than V 1RM, the low reliability of V last and the similar values of V last for both BP variants suggest that a standard V 1RM should be used to estimate the 1RM from the individualized load-velocity relationship.
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INTRODUÇÃO: Estudos comparando modelos de periodização em sequências de treinamento resistido (TR) realizadas do menor para o maior grupo muscular sobre as alterações musculares em indivíduos destreinados em TR são escassos. OBJETIVO: Comparar o efeito da periodização ondulatória (PO) e da periodização linear (PL) sobre a força máxima e hipertrofia muscular em uma sequência de execução dos exercícios dos menores para os maiores grupamentos musculares. MÉTODOS: Vinte e nove homens não experientes em (TR) foram distribuídos aleatoriamente em três grupos: PO (n =10), PL (n = 13) e grupo controle (GC, n = 9). Os indivíduos realizaram o teste de uma repetição máxima (1RM) nos exercícios rosca bíceps (RB), rosca tríceps (RT), puxada aberta (PA) e supino reto (SR), contração isométrica voluntária máxima (CIVM) e espessura muscular (EM) para flexores de cotovelo (FC) e extensores de cotovelo (EC) antes e após o período de 12 semanas de treinamento. O grupo PO variou o volume e a intensidade do treinamento diariamente, e o grupo PL a cada quatro semanas. O GC não realizou TR. Foi realizada uma ANOVA de dois caminhos com medidas repetidas, e cálculo do tamanho do efeito (TE), nas cargas obtidas para analisar o efeito do tratamento sobre as variações pré- e pós-período de TR. RESULTADOS: Os principais achados do estudo foram: 1) o grupo PO apresentou maior TE para 1RM dos exercícios RT e RB e para EM dos FC e EC quando comparado ao grupo PL; 2) não houve diferença no TE para os exercícios SR e PA que finalizavam a sessão. CONCLUSÃO: Ambos os modelos de periodização adotados foram eficientes para promover aumentos de força e hipertrofia muscular. Contudo, segundo o cálculo do TE, a PO promoveu maior incremento da força máxima nos exercícios que iniciaram a sessão e hipertrofia muscular.
INTRODUCTION: Studies comparing periodization models in sequences that begin with small muscle group and progressed toward large muscle group in untrained subjects in resistance training are scarce. OBJECTIVE: The purpose of this study was to compare the effects of ondulatory periodization and linear periodization models on maximum strength and muscular hypertrophy in a muscle group increasing exercise sequence. METHODS: Twenty-nine men with no experience in RT were randomly assigned into three groups: ondulatory periodization (OP, n = 10), linear periodization (LP, n = 13), and control group (CG, n = 9). The individuals performed 1RM tests in four exercises: biceps curl (BC), triceps extension (TE), lat pull down (LPD) and bench press (BP) and evaluations of maximum voluntary isometric contraction (MVIC), muscle thickness of elbow flexors (EF) and elbow extensors (EE) before and after the 12 weeks of training were carried out. The OP group varied in volume and intensity on a daily basis, while LP group varied every four weeks. The CG did not perform ST. A two-way ANOVA with repeated measures and the effect size (ES) were used to analyze muscle thickness, 1RM load improvement in each of the four exercises and the MVIC between groups. RESULTS: The major findings of this study were: 1) OP showed major ES for 1RM of BC and TE and for muscle thickness of EF and EE when compared with LP. 3) The ES data did not show significant differences for BP and LPD which finished the training session. CONCLUSIONS: We conclude that both periodization models were efficient at improving strength gains and muscular growth. However, ES data show that OP promotes major gains in strength for exercises that are positioned at the beginning of the session and hypertrophy.