Thiago Mattos Frota de Souza

Efeitos do treinamento de resistência de força com alto número de repetições no consumo máximo de oxigênio e limiar ventilatório de mulheres

The effects of strength training on womens cardiorespiratory capacity have not been widely established. The purpose of this study was to investigate the effects of resistance strength training with high number of repetitions on maximum oxygen uptake and ventilatory threshold in young women during 12 weeks. Twenty women, aged 21.2 + 2.7 years, were included in the study and assigned to two groups: I - resistance strength training with high number of repetitions group (TG, n = 10), and II - control group (CG, n = 10). All volunteers were submitted to the following protocol: anthropometry, cardiopulmonary testing on treadmill and 1 RM tests in the following exercises: leg-press 45o, seated leg extension, hamstring curl, bench press, lat pull-down, military press, standing barbell curls and lying barbell extension. The tests were performed before and after 12 weeks of training. Along the proposed period, the groups performed: I -TG: resistance exercises, the same of 1 RM tests, with three series of 25 repetitions, almost 30% of 1 RM; II - CG: no physical training whatsoever. CG did not show changes in the studied variables (p 0.05) after 12 weeks. It is concluded that the resistance strength training with high number of repetitions improved the aerobic power of volunteers, evidenced by the increase of maximum oxygen uptake. However, the ventilatory threshold did not change.

Comparison of maximal muscle strength of elbow flexors and knee extensors between younger and older men with the same level of daily activity.

Background Aging promotes neuromuscular loss, significantly reducing muscle strength. The magnitude of loss of strength seems to be different between the limbs, probably because of differences in activities of daily living (ADL). Therefore, the present study compared the muscle strength of the elbow flexors and knee extensors in younger (n = 7, mean age 23.3 ± 1.2 years) and older (n = 5, mean age 61.8 ± 2.6 years) men matched by ADL level. Methods The study participants performed maximal concentric, isometric, and eccentric contractions of the elbow flexors and knee extensors using an isokinetic dynamometer following a crossover study design. Changes in the dependent variables were compared using mixed model analysis (limb versus age). Results The main results demonstrated that concentric, eccentric, and mean contraction torques for knee extensors were significantly (P < 0.05) higher for younger men than for elderly men. On the other hand, no statistically significant difference (P > 0.05) was found in concentric, isometric, eccentric, and mean torques for elbow flexors between younger and older individuals. Conclusion These results show that elbow flexors maintain better strength than knee extensors through aging, even when comparing individuals with similar ADL levels.

The Effect Of Local Muscle Endurance Training on Cardiorespiratory Capacity in Young Women

Cesar, MC, Borin, JP, Gonelli, PRG, Simões, RA, Souza, TMF, and Montebelo, MIL. The effect of local muscle endurance training on cardiorespiratory capacity in young women. J Strength Cond Res 23(6): 1637-1643, 2009-The purpose of this study was to investigate the effect of local muscle endurance training on maximal oxygen uptake and ventilatory threshold in young women. Nineteen untrained women, ranging in age from 18 to 26 years, were included in the study and assigned to two groups: the control group (n = 10), and the resistance training group (n = 9). The following variables were obtained at baseline and after 12 weeks: body mass; maximal oxygen uptake, maximal heart rate, maximal oxygen pulse, oxygen uptake at the ventilatory threshold, heart rate at the ventilatory threshold, and oxygen pulse at the ventilatory threshold assessed by cardiopulmonary exercise testing on treadmill; 1-repetition maximum (RM) tests in bench press, latissimus pull down, military press, lying barbell extension, standing barbell curls, leg press, knee extension, and hamstring curl. The training group underwent resistance strength training. Loading during training followed the concept of maximum repetitions. Each session was defined as the performance of three sets of 15RM with a 60-second rest between sets and exercises. No significant changes were observed in the control group before and after 12 weeks (p > 0.05). All 1RM tests increased after training (p ≤ 0.01) in the training group, but no significant change was observed in body mass (p > 0.05). Cardiopulmonary variables showed no significant differences before and after resistance training (p > 0.05). These findings indicate that the local muscle endurance training realized produces no improvement in cardiorespiratory capacity in young women.

Electromechanical delay of the knee extensor muscles: comparison among young, middle-age and older individuals.

The aim of this study was to investigate the effects of the ageing process in the electromechanical delay (EMD), rate of torque development (RTD) and peak torque (PT) of the knee extensor muscles. The volunteers were assigned to three groups: young group (YG – 23·44 ± 4·74 years, 78·14 ± 15·11 kg, 1·72 ± 0·05 m), middle‐aged group (MAG – 49·56 ± 6·06 years, 72·01 ± 14·07 kg, 1·67 ± 0·06 m) and elderly group (EG – 68·67 ± 9·06 years, 67·96 ± 7·60 kg, 1·64 ± 0·07 m). The PT and RTD were assessed during maximal voluntary ballistic isometric contractions (MVBIC) in the isokinetic dynamometer. Muscle electrical activity was recorded (EMG) during MVBIC in the vastus lateralis (VL), vastus medialis (VM) and rectus femoris (RF) muscles. The EMD was calculated during the MVBIC, through the time interval between the EMG onset and torque onset. The PT and RTD were higher in the YG than in the MAG (P = 0·02; P = 0·01, respectively) and in the EG (P = 0·002; P = 0·0004, respectively). There were no significant differences in EMD among the three age groups for the VL, VM and RF (P>0·05) muscles. We conclude that age affects the PT and RTD, but not EMD of the VL, VM and RF muscles.

Concurrent Training with Blood Flow Restriction does not Decrease Inflammatory Markers

The aging process is associated with several changes in the elderly such as the decrease in cardiorespiratory fitness, strength and muscle mass, in addition to chronic low-grade inflammation. Concurrent training with blood flow restriction can be an interesting alternative to improve functional capacity with low mechanical stress in the elderly. The purpose of this study was to compare the inflammatory effects in older individuals submitted to two different protocols of concurrent training. Twenty-two healthy older adults (63.7±3.8 years; 69.8±8.9 kg; 1.6±0.1 m) performed 12 weeks of concurrent training (CT) or concurrent training with blood flow restriction (CTBFR) and the effects on inflammatory markers were analyzed. We found inflammatory behavior for the CTBFR group with a significant difference in serum concentration of C-reactive protein between pre- and post-moment (0.96±0.37 to 1.71±1.45, p=0.049), with no difference between groups, and a time effect in interleukin-6 (pre=0.86±0.43; post=1.02±0.46, p=0.016). We conclude that the CTBFR showed a pro-inflammatory profile after the period of intervention whereas the CT showed the opposite.

Influência da força muscular no volume e na intensidade da atividade física diária de idosos

Reduction in the volume daily physical activity (VAF – number of steps) and in the intensity of daily physical activity (IAF- average walk velocity) are related with higher incidence of falls and increase of incidence of chronic diseases in elderly. However, the identification of factors which may increase the VAF and the IAF became essential, especially in this population. Therefore, the aim of the present study was to investigate the influence of muscle strength in VAF and the IAF of older healthy elderly. It were recruited 18 participants, ten men and eight women, aged above 60 years old. The participants performed the one repetition maximal test (1-RM) and afterwards they used the triaxial accelerometer, during seven consecutive days, to measure the VAF and the IAF. To analyze the influence of muscle strength in the VAF and IAF a simple linear regression analysis was performed. It was not observed significant correlations between the muscle strength and the VAF (p = 0.93; r2 = −0.06), or between muscle strength and the IAF (p = 0.08; r2 = 0.17). In conclusion the muscle strength does not influence the VAF and IAF of healthy older adults.

The number of sessions required to stabilize peak torque and rate of torque development in isometric contractions in young, middle-age and older individuals

BACKGROUND AND OBJECTIVE: Maximal voluntary isometric contraction (MVIC) is used to determine both peak torque (PT) and rate of torque development (RTD). Familiarization sessions are usually performed to stabilize PT and RTD when performing MVIC. However, it is not clear how many familiarization sessions are required to achieve such stability in different age groups. METHODS: Thirty-three healthy individuals were divided into three groups: young group (YG; 5 men and 7 women, age 22.75 ± 4.53 years), middle-aged group (MAG; 6 men and 5 women, age 50.45 ± 6.12 years) and elderly group (EG; 6 men and 4 women, age 67.80 ± 7.28 years). Individuals performed the MVICs using an isokinetic dynamometer, in four different occasions separated by at least 72 hours. RESULTS: There were no differences in PT and RTD between familiarization sessions for all age groups ( P> 0.05). CONCLUSIONS: Our findings suggest that the present protocol of MVIC is capable of stabilizing PT and RTD in the first testing session in young, middle-aged and elderly groups.

Avaliação isocinética em atletas da seleção brasileira de futebol de 5

INTRODUCCION: La fuerza muscular (FM) de los miembros inferiores es uno de los principales componentes necesarios para acciones especificas durante la practica de futbol de 5 y, cuando presentan niveles insuficientes, los desequilibrios bilaterales elevados o acentuada diferencia en la razon agonista/antagonista (RAA), son factores que contribuyen para el desarrollo de lesiones musculoesqueleticas. OBJETIVO: En este sentido, la propuesta del estudio fue evaluar los niveles de torque maximo, diferencia bilateral en la produccion de fuerza y razon convencional de las musculaturas flexoras y extensoras de la rodilla en diferentes velocidades de ejecucion. METODOS: Participaron en el estudio 11 atletas con discapacidad visual. Los atletas fueron sometidos a evaluacion antropometrica para determinacion de la composicion corporal y sometidos a evaluacion en el dinamometro isocinetico para medir los niveles de desequilibrio muscular y la razon convencional. RESULTADOS: En los movimientos concentricos de la musculatura flexora, se observaron diferencias significativas en el pico de torque (PT) entre los miembros dominantes (MD) y no dominante (MND) en la velocidad de 60°.s-1 y 180°.s-1, en el pico de torque normalizado (PTN) a 60°.s-1 y 180°.s-1 para los musculos extensores. En la RAA se observo diferencia significativa entre MD y MND, y niveles aceptables de RAA en ambas piernas de acuerdo con lo propuesto para el futbol convencional. CONCLUSION: Se espera que los resultados del presente estudio puedan contribuir para los procesos de prevencion, entrenamiento y rehabilitacion de los atletas de futbol de 5, asi como tambien que sirvan como parametros para futuros estudios.

Adição de exercício resistido durante treino aeróbio prolonga a duração da hipotensão pós-exercício

Resumen pt: Objetivo: Analisar a adicao de exercicios resistidos em treino aerobio na hipotensao pos-exercicio (HPE). Metodos: Nove normotensos, do sexo masculino, e...

CARGA PARA A APLICAÇÃO DE TESTES DE 1-RM EM EXERCÍCIOS DE MEMBROS SUPERIORES EM MULHERES JOVENS TREINADAS E NÃO TREINADAS

The purpose of this study was to propose reference values to application of the 1-Rm tests in young women trained and untrained. 90 women, 18-31 years, grouped into: 43 Trained (GT) and 47 Untrained (GNT) were submitted to 1-Rm tests in the following exercises: bench press, shoulder press, biceps curl and lying triceps ex- tension. GT showed higher values than GNT in absolute and relative terms: bench press (GT = 36.44 kg/0.63 and GNT = 27.34 kg/0.46), shoulder press (GT = 27.93 kg/0.49 and GNT = 22.70 kg/0.38), biceps curl (GT = 21.63 kg/0.37 and GNT = 15.57 kg/0.26) and lying triceps extension (GT = 18.09 kg/0.31 and GNT = 12.55 kg/0.21). The values found in this study can be used as references of load to application of 1-Rm tests.