No abstract

The purpose of this study was to investigate the effects of antagonist passive static stretching (AS) during the inter-set rest period on repetition performance and muscle activation. Ten trained men (22.4 ± 0.9 years) participated in this study. Two protocols were adopted: Passive recovery (PR)--three sets to repetition failure were performed for the seated row (SR) with two-minute rest interval between sets without pre-exercise stretching; AS--forty seconds of stretching was applied to pectoralis major prior to each set of SR. Significant increases in the number of repetitions were noted under AS compared with PR (p < 0.05). Significant increases on latissimus dorsi (p = 0.002) and biceps brachii (p = 0.001) muscle activity were noted inter-sets under the AS compared with the PR condition. Therefore, the AS adopted during the inter-set rest period may enhance repetition performance and activation of agonist muscles in an acute manner.

Machado, W, Paz, G, Mendes, L, Maia, M, Winchester, JB, Lima, V, Willardson, JM, and Miranda, H. Myoeletric activity of the quadriceps during leg press exercise performed with differing techniques. J Strength Cond Res 31(2): 422-429, 2017-The quadriceps muscle supplies the motive force for dynamic knee extension. During this action, the vastus medialis oblique (VMO) and vastus lateralis (VL) co-contract to stabilize the patella as it tracks within the patellofemoral groove. The purpose of this study was to analyze surface electromyographic (SEMG) responses for the VL, VMO, rectus femoris (RF), and biceps femoris (BF), as well as the VMO:VL ratio during an open-kinetic chain 45° angled leg press (LP45). The traditional LP45 technique was compared with 2 alternative LP45 exercise techniques that used a physioball and elastic band, respectively. Thirteen female college students performed 3 protocols in random order: TRAD-1 LP45 set performed using the traditional exercise technique, PBALL-1 LP45 set performed with a physioball held between the knee joints, and PEB-1 LP45 set performed with an elastic band proximal to the knee joints. Ten repetitions at 70% of a 10 repetition maximum load were performed in each protocol, and the SEMG data were recorded for the VMO, VL, RF, and BF muscles. Significant increases in VMO activity were noted during PBALL vs. PEB (p = 0.001) and TRAD (p = 0.002). Higher VMO activity was noted during TRAD vs. PEB (p = 0.001). Greater VL activity was noted during PBALL vs. TRAD (p = 0.0001) and PEB (p = 0.0001). The PBALL condition elicited a greater VMO:VL ratio during the concentric phase vs. the PEB (p = 0.001) and TRAD (p = 0.001) protocols. Greater RF activity was observed during PEB vs. TRAD (p = 0.001) and PBALL (p = 0.001). Therefore, practitioners should consider placing a physioball between the knees during the LP45 exercise as an alternative technique when greater overall quadriceps activity is desired for clinical rehabilitation or a muscle strengthening program.

Therefore, both physioball and elastic band can be adopted during LP with the goal to reduce excessive varus and valgus forces, respectively, even performing consecutive sets with submaximal loads. Furthermore, this may be an interesting alternative to increasing quadriceps activation and improving the knee joint stabilization.

The purpose of this study was to compare training volume, post-exercise hypotension (PEH) and heart rate variability (HRV) responses to different strength training methods. Thirteen trained men volunteered for this study. Three training methods were completed in a randomized design, which included: Traditional Set (TS) - three successive sets for the lying bench press (LBP), lat pulldown (LPD), incline 45° bench press (BP45), seated close-grip row (SCR), triceps extension (TE), and biceps curl (BC), with a 90 sec. rest interval between sets and exercises; Paired Set (PS) - three paired sets for the LBP-LPD, BP45-SCR, and TE-BC, with a 90 sec. rest interval between sets and exercises; and Super-Set (SS) - three super-sets for the LBP-LPD, BP45-SCR, and TE-BC. During the SS session, no rest was permitted between paired sets, followed by 180 sec. rest after each super-set. Ten repetition maximum (RM) loads were adopted for all exercises. Blood pressure and HRV were measured at baseline, immediately post-session, and at 10 min. intervals until 60 min. post session. Significantly greater training volume was noted under the SS method (8608.6 ± 2062.2 kg) versus the TS method (7527.5 ± 2365.1kg), respectively. Significantly greater training volume was also observed under the PS method (8262.3 ± 2491.2kg) versus the TS method (p ≤ 0.05). No main effects for HRV and PEH were noted between protocols (p > 0.05). However, similar PEH responses intra-protocol were observed for the TS, PS and SS methods (p ≤ 0.05). Considering the duration of the PEH intra-protocol, large effect sizes were noted for the SS and PS methods versus the TS method in diastolic and mean blood pressure. Therefore, both the PS and SS methods may be an alternative to the TS method to achieve greater total work and training volume with a tendency towards a longer PEH response.

No abstract

Os métodos de treinamento de força são aplicados através da manipulação das variáveis metodológicas, que podem modificar as características do treinamento. Dessa forma, o objetivo do presente estudo foi investigar o efeito do método de séries pareadas de agonista-antagonista (PAA) versus o método tradicional (MT) sobre o volume total de treinamento (VTT) ou eficácia, a eficiência (VTT/tempo) e o sinal eletromiográfico (EMG). Participaram do estudo 10 sujeitos treinados (22,4 ± 0,9 anos, 173 ± 5 cm, 74,8 ± 7,8kg, 13,1 ± 2,3% gordura corporal). No MT foram realizadas 3 séries no exercício de supino vertical (SV) e, em seguida, 3 séries na remada aberta (RA). No PAA foram realizadas 3 séries pareadas entre o SV e RA. Foram adotados dois minutos de intervalo entre as séries em ambos os protocolos. Os sinais de EMG do latíssimo do dorso (LD), porção clavicular do peitoral maior (PMC), bíceps braquial (BB) e tríceps braquial cabeça longa (TBL) foram coletados durante a RA. Para as comparações entre os protocolos e séries aplicou-se a ANOVA two-way e post hoc de Bonferroni adotando-se p < 0,05. Verificou-se aumento significativo no VTT no PAA comparado ao MT. A atividade EMG dos músculos LD e BB foi significativamente maior no PAA em comparação ao MT. Em relação ao PMC e TBL, verificou-se redução significativa no PAA comparado ao MT. Logo, o PAA parece ser uma opção interessante em programas que visam aumento no VTT, bem como, economia de tempo (eficiência) sem comprometer o desempenho muscular.

Based on these findings, clinicians may expect young male and female volleyball athletes to demonstrate similar and symmetrical lower-extremity 2-dimensional knee joint FPPA values across screening tests intended to identify lower-extremity injury risk factors. However, greater FPPA values should be expected during the more dynamic DVJ task.