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Santana, HG, Paz, GA, Willardson, JM, de Araújo Farias, D, and Miranda, H. Effects of differing foam rolling periods on training volume and myoelectric responses of lower-body muscles. J Strength Cond Res 36(12): 3311-3318, 2022-Foam rolling (FR) is a practice that has increased in popularity before and after resistance training. The purpose of this study was to compare the acute effects of different foam rolling periods for the lower body muscles on subsequent performance, myoelectric activity and rating of perceived exertion in trained men. Fourteen men (26.2 ± 3.2 years, 178 ± 0.04 cm, 82.2 ± 10 kg and body mass index 25.9 ± 3.3kg/m -2 ) volunteered for this study. Four repetition maximum (4-RM) loads were determined for hexagonal bar deadlift and 45°-angled leg press during test and retest sessions over two nonconsecutive days. The experimental conditions included a traditional protocol (TP) with no prior foam rolling, and four other conditions that involved FR applied to the quadriceps, hamstrings and triceps surae for one set of 30 sec (P1), two sets of 30 sec (P2), three sets of 30 sec (P3), or four sets of 30 sec (P4).The resistance training consisted of five sets with 4-RM loads. The number of repetitions completed, the myoelectric activity of lower limbs were recorded, as well as the rating of perceived exertion for each protocol. There were no differences between the protocols in the total repetitions for the hexagonal bar deadlift and 45° angled leg press exercises. Similar results between protocols were also noted for muscle activity and rated perceived exertion (RPE). Therefore, the results of the present study indicated that the FR didn't provide effects on performance, myoelectric activity and rating of perceived exertion responses during high intensity resistance performance for lower limb exercises.

Summary Objectives The purpose of this study was to examine myoelectric activity, fatigue index and volume load adopting different intersession recovery periods between repeated resistance training (RT) bouts. Methods Fifteen recreationally-trained men participated in this study. Eight-repetition maximum (8RM) loads were determined for the bench press (BP) and 30° incline bench press (BP30) over two non-consecutive days. Three experimental protocols were performed in randomized order to examine the effect of different intersession recovery periods between repeated RT sessions for upper body muscles (pectoral major activity, anterior deltoid, triceps brachii, and biceps brachii) on volume load and myoelectric activity (SEMG), including: 24 hours (P24); 48 hours (P48); and 72 hours (P72). Each RT session consisted of performing four sets to failure for the BP and BP30 with 8-RM loads and 2-minute rest intervals between sets. Results The results showed that for SEMG activity, during the BP and BP30 exercises, there were no significant main effects for session, protocol, or interaction between protocols and sessions in the percentage difference between sets in activity of all muscles analyzed. Considering the overall session volume load, a significant main effect for session was noted. Volume load was significantly lower in Session 2 versus Session 1 under the P24 h protocol, without significant differences between the P48 and P72. Conclusion Therefore, coaches and practitioners who need to accomplish a higher volume load without negatively impacting fatigue index and myoelectric activity for upper body muscles, should adopt recovery periods longer than 24 hours between similar RT bouts.

Study design: Cross-over study. Context: The squat, single-leg squat, forward lunge, and reverse lunge are fundamental movements often performed in activities of daily living, sports competitions, and sport-specific training. Objective: The purpose of this study was to investigate the effect of visual feedback with a laser sensor (VFLS) versus a control condition on the myoelectric activity (surface electromyography [sEMG]) of the vastus medialis oblique (VMO), vastus lateralis, gluteus medius (Gmed), and erector spinae muscles during the performance of several squat variations with bodyweight. Methods: Nineteen female college students (20 [2.5] y, 165.3 [10.2] cm, 66.4 [4.1] kg, 2 [1.2] y of resistance training experience) with a background in strength or sports training volunteered to participate in this study. Over 4 separate visits, subjects performed 2 sets of 10 repetitions of a squat variation exercise in random order (ie, squat, single-leg squat, forward lunge, and reverse lunge). The first set of a given squat variation condition was considered a control set, and then after 3-minute rest, a second set was performed with VFLS. Results: Significant decreases in VMO and Gmed myoelectric activity were observed during the VFLS set versus the control set for the forward lunge exercise (P = .03). No differences were observed between the control set and VFLS set in the sEMG normalized signal for all muscles analyzed for the squat and single-leg squat, respectively. However, the sample entropy of the sEMG signal for the erector spinae became more irregular during the VFLS set versus the control set for the squat exercise (P = .01), whereas the Gmed presented a more irregular sEMG signal during the VFLS set versus the control set for the single-leg squat (P = .08). Conclusion: Laser sensor biofeedback may induce significant decreases in VMO and Gmed activation performing forward lunge exercise. Therefore, laser sensor biofeedback may induce a reduction in muscle activity of neutralizers muscles during a few squat bodyweight variations (bilateral, single-leg, forward, and reverse lunge).

Simão, R, Polito, M, de Salles, BF, Marinho, DA, Garrido, ND, Santos Junior, ERT, and Willardson, JM. Acute and long-term comparison of fixed vs. self-selected rest interval between sets on upper-body strength. J Strength Cond Res 36(2): 540-544, 2022-The effects of different rest interval durations between sets has been widely studied, but only recently, the self-selected rest interval (SSRI) has been a matter of interest. However, previous studies comparing fixed and SSRI have investigated only acute responses. The purpose of this study was to analyze the acute and long-term effects of a fixed rest interval (FRI) vs. an SSRI between sets on upper-body performance and strength gains. Thirty-three trained men were randomly divided into 2 groups: FRI (75 seconds between sets), and SSRI. Both groups performed 3 sets with 75% of 1-repetition maximum until repetition failure in the chest press (CP), lat pull-down (LPD), shoulder press (SP), and seated row (SR) 3 times a week for 8 weeks. The results demonstrated that the SSRI allowed for significantly greater repetition performance vs. the FRI in the CP (26.1 ± 2.0 vs. 21.5 ± 1.8), LPD (30.1 ± 2.3 vs. 24.9 ± 1.9), SP (24.0 ± 2.8 vs. 17.4 ± 1.5), and SR (26.3 ± 1.6 vs. 22.0 ± 1.6). In addition, the following strength gains were observed: SSRI (CP: 6.8%, LPD: 8.0%, SP: 6.7%, SR: 7.8%) and FRI (CP: 7.4%, LPD: 6.7%, SP: 6.1%, SR: 7.0%) without significant differences between the groups. In conclusion, within an 8-week period, both protocols seem to be effective for strength gains, despite the higher training volume accomplished by the SSRI group. However, the FRI was 37% more time efficient.

Miranda, H, de Souza, JAAA, Scudese, E, Paz, GA, Salerno, VP, Vigário, PdS, and Willardson, JM. Acute hormone responses subsequent to agonist-antagonist paired set vs. traditional straight set resistance training. J Strength Cond Res 34(6): 1591-1599, 2020-The purpose of this study was to compare acute hormone responses and rating of perceived exertion (OMNI-Res) subsequent to the agonist-antagonist paired set (PS) vs. the traditional straight set (TS) resistance training method. Twelve recreationally trained men (25.7 ± 4.7 years, 173 ± 6.3 cm and 71.5 ± 6.6 kg) participated in the current study. After 10 repetition maximum (RM) load determination, each subject performed the following 2 experimental sessions in random order: TS session-3 sets of 10 repetitions at 85% of 10RM for the machine seated row and barbell bench press with 2-minute rest intervals between sets; and PS-3 sets of 10 repetitions with 85% of 10RM alternating machine seated row and barbell bench press for the total of 6 PSs with 2-minute rest intervals between sets. Total testosterone (TT), free testosterone (FT), cortisol, TT/cortisol ratio, growth hormone (GH), and blood lactate concentrations were measured before workout and immediately after workout and 15 and 30 minutes after workout. The OMNI-RES was recorded at the end of each set for both exercises within each session. Under the TS session, TT significantly increased immediately post-workout vs. the pre-workout time point. For the PS session, TT significantly decreased at 30-minute post-workout vs. the immediate post-workout time point, whereas, FT significantly increased immediately post-workout and 15-minute post-workout vs. the pre-workout time point. For the TS session, GH significantly increased immediately post-workout, and at the 15- and 30-minute post-workout time points vs. the pre-workout time point, respectively. For the PS session, GH was significantly increased immediately post-workout vs. the pre-workout time point. Blood lactate significantly increased at all post-workout time points vs. the pre-workout time point under both sessions. The cortisol and TT/cortisol ratio showed no differences between sessions. In conclusion, from an acute standpoint, the TS approach showed a tendency to cause greater disruption in hormone levels, despite the lack of significant differences vs. the PS approach at all time points. However, both strategies may promote similar acute hormone responses.

This study investigated the relationship between habitual nutritional intake and the responsiveness of elderly individuals to resistance training. Nineteen participants (66.0 ± 4.5 years) completed body composition (dual-energy X-ray absorptiometry), functional capacity (timed-up-and-go, stair ascent, and stair descent), and neuromuscular tests (5-repetition maximum and countermovement jump) before and after a 9-week resistance training intervention. Habitual nutritional intake was evaluated at the beginning, middle, and end of the intervention. Participants were also divided into two groups based on their protein intake (low protein group 1.2 g/kg). Total Kcaloric and protein intake explained ~ 21–44% of the functional capacity improvements, while total Kcaloric and carbohydrate intake explained ~ 21–27% of the change in lean mass. Participants with high protein intake showed greater percentage improvement for timed-up-and-go (− 10.7 ± 4.9% and 0.4 ± 7.4%) and stair ascent (− 11.4 ± 7.6% and − 3.2 ± 5.3%) versus those with lower protein intake. Nutritional intake influenced individual responsiveness to resistance training in the elderly. Older adults with higher Kcaloric, protein, and carbohydrate intake presented greater improvement in functional capacity and lean mass following resistance training.

Purpose: This study compared the acute effects of two different resistance training methods on heart rate variability, blood pressure, and rating of perceived exertion in patients with liver cirrho...

The post-exercise hypotension response (PEH) has been shown to be dependent on the load and volume of a resistance training (RT) prescription. The aim of the present study was to compare the PEH between a low-load and high-volume and a high-load and low-volume RT session. Ten young men with more than 2 years of RT experience participated in the study. All subjects were submitted to 5 and 15 repetition maximum tests, in counterbalanced order, for the following exercises: back squat, chest press, leg press and wide grip pulldown. Then, the subjects performed two protocols (P5 and P15) that consisted of three sets to volitional failure with 2-min rest intervals between sets and exercises. Blood pressure (BP) and heart rate (HR) were measured before and after 60 min following each session at 10-min time points. Significantly greater total training volume was observed for all exercises in P15 (p

espanolObjetivo: Examinar el efecto de la prefatiga del triceps braquial en el desempeno subsiguiente de la fuerza y actividad mioelectrica en el supino recto utilizando barra (SRB), mancuernas (SRM) y Smith machine (SMSR). Metodo: En el estudio participaron 19 hombres entrenados (27.9 ± 4.5 anos, 1.72 ± 0.1 m, 80.3 ± 9.2 kg). Se realizo una prueba de diez repeticiones maximas para la extension del triceps, asi como para el supino resto utilizando barra, mancuernas y Smith Machine. Se realizaron tres protocolos experimentales en orden aleatorizado. Los protocolos consistieron de cuatro series de repeticiones de extension del triceps (realizado con polea alta) hasta la fatiga, seguida de cuatro series de repeticiones hasta la fatiga de una de las tres modalidades de supino. Dos intervalos de descanso de un minuto se realizaron entre series y ejercicios. Las repeticiones totales (trabajo), volumen de entrenamiento y actividad mioelectrica de pectoral mayor, deltoides anteriores, biceps braquial y triceps braquial fueron registradas durante cada modalidad de supino. Resultados: Se observo una actividad significativamente mayor del biceps braquial durante la realizacion del supino recto con mancuerna versus barra y Smith Machine. No se observo ninguna diferencia significativa entre los protocolos. Conclusiones: Por lo tanto, considerando el volumen de entrenamiento y la actividad mioelectrica de los musculos sinergicos, se puede esperar un rendimiento similar en las diversas modalidades de supino, cuando es precedido por la realizacion de una extension de triceps. EnglishObjective: The purpose of this study was to examine the effect of pre-fatiguing the triceps brachii on subsequent strength performance and myoelectric activity in the barbell, dumbbell, and Smith machine bench press. Method: Nineteen trained men participated of this study (27.9 ± 4.5 years; 1.72 ± 0.1 m; 80.3 ± 9.2 kg). Ten-repetition maximum loads were determined for the triceps extension as well as the barbell barbell, dumbbell and Smith machine bench press. Three experimental protocols were performed in a randomized design. All experimental protocols began with four sets of the triceps extension (performed with a high pulley) to repetition failure followed by four sets to repetition failure for one of three bench press modalities. Two minute-rest intervals were adopted between sets and exercises. Total repetitions (work), training volume and myoelectric activity of pectoralis major, anterior deltoid, biceps brachii, and triceps brachii were recorded during each bench press modality. Results: Significantly greater activity of the biceps brachii was observed during performance of the dumbbell bench press versus barbell and Smith machine bench press. No other significant differences were observed between protocols. Conclusion: Therefore, considering the training volume and myoelectric activity of the synergistic muscles, similar performance across bench press modalities can be expected when preceded by performance of a triceps extension. portuguesObjetivo: examinar o efeito da pre-fatiga do triceps braquial no desempenho subsequente da forca e atividade mioeletrica no supino reto utilizando barra, halter e Smith machine. Metodo: Participaram do estudo 19 homens treinados (27.9 ± 4.5 anos; 1.72 ± 0.1 m; 80.3 ± 9.2 kg). Foi realizado um teste de dez repeticoes maximas para a extensao do triceps, assim como para o SRB, SRH e SMSR. Tres protocolos experimentais foram realizados em ordem randomizada. Os protocolos consistiram de quatro series de repeticoes do a extensao do triceps (realizado com polia alta) ate a falha seguida de quatro series de repeticoes ate a falha de uma das tres modalidades de supino. Dois intervalos de descanso de um minuto foram adotados entre series e exercicios. As repeticoes totais (trabalho), volume de treinamento e atividade mioeletrica de peitoral maior, deltoide anterior, biceps braquial e triceps braquial foram registradas durante cada modalidade de supino. Resultados: Observou-se uma atividade significativamente maior do biceps braquial durante a realizacao do supino reto halter versus barra e Smith Machine. Nenhuma outra diferenca significativa foi observada entre os protocolos. Conclusoes: Portanto, considerando o volume de treinamento e a atividade mioeletrica dos musculos sinergicos, pode-se esperar um desempenho semelhante em modalidades de supino quando precedido pela realizacao de uma extensao de triceps.

espanolObjetivo: evaluar la eficacia de tres semanas de un entrenamiento de potencia en bloque utilizando dos configuraciones diferentes de conglomerados con equipo neumatico sobre el desempeno en el Sprint. Metodo: treinta individuos recreacionales activos participaron en este estudio (18 mujeres y 12 hombres). Los sujetos fueron distribuidos aleatoriamente en los grupos Control (GC), Cluster 1 (CL1) y Cluster 2 (CL2). El procedimiento experimental implico un periodo de entrenamiento de tres semanas; en los momentos pre y post-entrenamiento se aplicaron pruebas de Sprint de 20 metros. Resultados: hubo una diferencia significativa intergrupos para el CL2 versus CG en el tiempo, aceleracion y velocidad en los primeros 10 metros de Sprint. El valor alfa utilizado fue p Conclusion: estos resultados sugieren que las intervenciones con intervalos intra-series (especificamente CL2) utilizando equipo neumatico permiten adaptaciones positivas a la velocidad y la aceleracion despues de tres semanas de entrenamiento. EnglishObjective: The purpose of the present study was to evaluate the effectiveness of a three-week power-training block with two different cluster set configurations using pneumatic equipment on sprint performance. Method: Thirty recreationally active subjects participated in this study (18 female and 12 male). The subjects were distributed randomly into Control (CG), Cluster 1 (CL1) and Cluster 2 (CL2) groups. The experimental procedure involved a three-week training period; at the pre- and post-training time points, a 20-meter sprint tests were applied. Results: There was an intergroup significant difference for the CL2 versus the CG for time, acceleration and velocity in the first 10-meter sprint test. The alpha value used was p Conclusion: These results suggest that interventions with intra-set intervals (specifically CL2) using pneumatic equipment allow for positive adaptations in velocity and acceleration after three-week training. portuguesObjetivo: avaliar a eficacia de tres semanas de um treinamento de potencia em bloco utilizando duas configuracoes diferentes de cluster set com equipamento pneumatico sobre o desempenho de Sprint. Metodo: Trinta individuos recreacionalmente ativos participaram deste estudo (18 mulheres e 12 homens). Os sujeitos foram distribuidos aleatoriamente nos grupos Controle (GC), Cluster 1 (CL1) e Cluster 2 (CL2). O procedimento experimental envolveu um periodo de treinamento de tres semanas; nos momentos pre e pos-treinamento foram aplicados testes de Sprint de 20 metros. Resultados: Houve uma diferenca significativa intergrupos para o CL2 versus CG no tempo, aceleracao e velocidade nos primeiros 10 metros de Sprint. O valor alfa utilizado foi p Conclusao: Estes resultados sugerem que intervencoes com intervalos intraseries (especificamente CL2) utilizando equipamento pneumatico permitem adaptacoes positivas na velocidade e aceleracao apos tres semanas de treinamento.

Paz, GA, Iglesias-Soler, E, Willardson, JM, Maia, MdF, and Miranda, H. Postexercise hypotension and heart rate variability responses subsequent to traditional, paired set, and superset resistance training methods. J Strength Cond Res 33(9): 2433-2442, 2019-The purpose of this study was to compare training volume, postexercise 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)-3 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-second rest interval between sets and exercises; Paired Set (PS)-3 paired sets for the LBP-LPD, BP45-SCR, and TE-BC, with a 90-second rest interval between sets and exercises; and superset (SS)-3 supersets for the LBP-LPD, BP45-SCR, and TE-BC. During the SS session, no rest was permitted between PSs, followed by 180 seconds of rest after each SS. Ten repetition-maximum (RM) loads were adopted for all exercises. Blood pressure (BP) and HRV were measured at baseline, immediately aftersession, and at 10-minute intervals until 60 minutes after session. Significantly greater training volume was noted under the SS method (8,608.6 ± 2,062.2 kg) vs. the TS method (7,527.5 ± 2,365.1 kg), respectively. Significantly greater training volume was also observed under the PS method (8,262.3 ± 2,491.2 kg) vs. the TS method (p ≤ 0.05). No main effects for HRV and PEH were noted between protocols (p > 0.05). However, similar PEH response intraprotocols were observed for the TS, PS, and SS methods (p ≤ 0.05). Considering the duration of the PEH intraprotocol, large effect sizes were noted for the SS and PS methods vs. the TS method in diastolic and mean BP. Therefore, both the PS and SS methods may be an alternative to the TS method to achieve greater total repetitions and training volume with a tendency toward a longer PEH response.

Prestes, J, Tibana, RA, de Araujo Sousa, E, da Cunha Nascimento, D, de Oliveira Rocha, P, Camarco, NF, Frade de Sousa, NM, and Willardson, JM. Strength and muscular adaptations after 6 weeks of rest-pause vs. traditional multiple-sets resistance training in trained subjects. J Strength Cond Res 33(7S): S113-S121, 2019-The purpose of this study was to compare the longitudinal effects of 6 weeks of rest-pause vs. traditional multiple-set resistance training (RT) on muscle strength, hypertrophy, localized muscular endurance, and body composition in trained subjects. Eighteen trained subjects (mean ± SD; age = 30.2 ± 6.6 years; weight = 74.8 ± 17.2 kg; height = 171.4 ± 10.3 cm) were randomly assigned to either a traditional multiple-set group (n = 9; 7 men and 2 women; 3 sets of 6 repetitions with 80% of 1-repetition maximum (1RM) and 2-minute rest intervals between sets) or a rest-pause group (n = 9; 7 men and 2 women). The results showed no significant differences (p > 0.05) between groups in 1RM strength (rest-pause: 16 ± 11% for bench press, 25 ± 17% for leg press and 16 ± 10% for biceps curl vs. traditional multiple-set: 10 ± 21% for BP, 30 ± 20% for LP and 21 ± 20% for BC). In localized muscular endurance, the rest-pause group displayed significantly greater (p < 0.05) repetitions, only for the LP exercise (rest pause: 27 ± 8% vs. traditional multiple-set: 8 ± 2%). In muscle hypertrophy, the rest-pause group displayed significantly greater (p < 0.05) thickness, only for the thigh (rest-pause: 11 ± 14% vs. traditional multiple-set: 1 ± 7%). In conclusion, RT performed with the rest-pause method resulted in similar gains in muscle strength as traditional multiple-set training. However, the rest-pause method resulted in greater gains in localized muscular endurance and hypertrophy for the thigh musculature.

Behenck, C, Sant'Ana, H, Pinto de Castro, JB, Willardson, JM, and Miranda, H. The effect of different rest intervals between agonist-antagonist paired sets on training performance and efficiency. J Strength Cond Res 36(3): 781-786, 2022-The purpose of this study was to verify the effect of different rest intervals (RIs) between agonist-antagonist paired sets (APS) on training performance and efficiency. Eighteen recreationally trained men (age: 21.5 ± 2.1 years, body mass: 74.5 ± 10.4 kg, height: 1.75 ± 0.04 m, body mass index: 24.4 ± 3.7 kg·m-2) completed 4 sessions. During each session, a 10-repetition maximum load was used for 3 APS of Bench Row + Bench Press and Lat Pull-down + Overhead Press with RI between APS sequences of 1, 2, 3 minutes (min) or self-selected RI (SRI). Total training volume (TTV), session time and efficiency were measured in all sessions. The 1-minute RI resulted in significantly less TTV vs. the other conditions (p = 0.000). The 2-minute RI resulted in significantly less TTV vs. the 3-minute RI (p = 0.002), but the SRI was not significantly different vs. the 3-minute RI. For session time, the 1-minute RI was significantly less (p = 0.000) and the 3-minute RI was significantly greater (1-minute and 2-minute RI, p = 0.000; SRI, p = 0.010) than the other conditions. Therefore, the efficiency of the 1-minute RI was significantly greater vs. the other conditions (3-minute RI and SRI, p = 0.000; 2-minute RI, p = 0.001) and the 2-minute RI was significantly greater vs. the 3-minute RI (p = 0.001). There were no significant differences in TTV, session time, and efficiency between the 2-minute RI and SRI conditions. In conclusion, the 2-minute RI and SRI conditions may present a better cost-effectiveness. It is suggested that self-selected RI can provide better performance, whereas 2-minute RI may enable greater efficiency.

Background A challenging aspect of research in sports science is designing and conducting studies that simulate actual workout scenarios, especially with application to resistance training (RT). Therefore, the purpose of this study was to compare the effects of RT sessions performed in differing workout formats on myoelectric activity, strength performance, and metabolic markers (creatine kinase, lactate dehydrogenase, blood lactate) over 24, 48 and 72 hours post-workout. Methods Twenty-two trained men (25.2±4.1 years, 182.1±12.3 cm and 91.2±5.9 kg) performed the following four training protocols with 10-repetition maximum loads in random order: 1) traditional set (TS): three sets were performed in succession for the barbell bench press (BP), lat pulldown (LPD), 45° incline bench press (BP45), seated close-grip row (SCR), triceps extension (TE) and biceps curl (BC) on a pulley; 2) paired set (PS): three paired sets were performed as follows: BP-LPD, BP45-SCR, and TC-B; 3) super-set (SS): similar to the PS protocol, but without rest between paired exercises; 4) circuit training (CT): one set of each exercise was performed sequentially three times. Results The results showed greater total volume under the SS (8063.2±2270.5 kg) protocol versus the TS (7356.8±2279.7 kg). Total work (repetitions) was also significantly greater for the SS and CT protocols versus the TS (P Conclusions Therefore, the practitioners should consider utilizing the SS method during time-constrained periods with the goal to achieve greater training volume in time-efficient manner versus the TS, PS and CT methods.

Berzerra, ES, Orssatto, LBR, Moura, BM, Willardson, JM, Simão, R, and Moro, ARP. Mixed session periodization as a new approach for strength, power, functional performance, and body composition enhancement in aging adults. J Strength Cond Res 32(10): 2795-2806, 2018-The purpose of this study was to compare the effects of mixed session periodization (MSP) vs. traditional periodization (TP) on strength, power, functional performance, and body composition in aging adults. Forty-five healthy aging adults were randomly divided into 3 groups: MSP, TP, and Control. Subjects were tested before the intervention for baseline values (week 4) and then repeated testing during (week 7 and week 11), as well as after the intervention (week 15). Subjects were tested on the following performance measures: 5 repetition maximum (5RM) leg press and seated leg curl; 12RM cable chest press; countermovement jump (CMJ) and squat jump; up-and-down stairs; timed up and go (TUG); and body composition. All comparisons were analyzed through a mixed-model analysis with repeated measures (group × time) and with Bonferroni post hoc tests (p ≤ 0.05). After the intervention, no significant differences were observed between experimental groups; however, the MSP and TP groups demonstrated significantly greater values vs. the Control group in the 5RM leg press (p0.01), seated leg curl (p0.01), and 12RM cable chest press (p0.001). For CMJ performance, the MSP and TP groups significantly increased at week 7 (p0.001). The MSP and TP groups significantly improved functional task performance, including TUG (p0.001), upstairs (p0.01), and downstairs (p0.01) after training. Furthermore, body composition for the lower limbs significantly changed for the MSP and TP groups, with increased fat-free mass (p0.001) and decreased fat mass (p0.01) after training. In conclusion, the MSP and TP models used in this study were equally effective in developing strength, power, and functional performance while increasing fat-free mass and improving body fat percentage in aging adults. However, it should be considered that the MSP protocol did result in greater effect sizes in lower-limb strength, lower-limb fat-free mass, up-and-down stair, and TUG performance.

Farias, DdA, Willardson, JM, Paz, GA, Bezerra, EdS, and Miranda, H. Maximal strength performance and muscle activation for the bench press and triceps extension exercises adopting dumbbell, barbell and machine modalities over multiple sets. J Strength Cond Res 31(7): 1879-1887, 2017-The purpose of this study was to investigate muscle activation, total repetitions, and training volume for 3 bench press (BP) exercise modes (Smith machine [SMBP], barbell [BBP], and dumbbell [DBP]) that were followed by a triceps extension (TE) exercise. Nineteen trained men performed 3 testing protocols in random order, which included: (P1) SMBP + TE; (P2) BBP + TE; and (P3) DBP + TE. Each protocol involved 4 sets with a 10-repetition maximum (RM) load, immediately followed by a TE exercise that was also performed for 4 sets with a 10RM load. A 2-minute rest interval was adopted between sets and exercises. Surface electromyographic activity was assessed for the pectoralis major (PM), anterior deltoid (AD), biceps brachii (BB), and triceps brachii (TB). The results indicated that significantly higher total repetitions were achieved for the DBP (31.2 ± 3.2) vs. the BBP (27.8 ± 4.8). For the TE, significantly greater volume was achieved when this exercise was performed after the BBP (1,204.4 ± 249.4 kg) and DBP (1,216.8 ± 287.5 kg) vs. the SMBP (1,097.5 ± 193 kg). The DBP elicited significantly greater PM activity vs. the BBP. The SMBP elicited significantly greater AD activity vs. the BBP and DBP. During the different BP modes, the SMBP and BBP elicited significantly greater TB activity vs. the DBP. However, the DBP elicited significantly greater BB activity vs. the SMBP and BBP, respectively. During the succeeding TE exercise, significantly greater activity of the TB was observed when this exercise was performed after the BBP vs. the SMBP and DBP. Therefore, it seems that the variation in BP modes does influence both repetition performance and muscle activation patterns during the TE when these exercises are performed in succession.

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.

Background: Foam rolling (FR) has become very popular in recent years, however, the practice of FR between sets of resistance training (RT) for the lower limbs needs further examination. Purpose: Therefore, the purpose of the present study was to examine the effect of FR for the agonists (quadriceps) and antagonists (hamstrings) between multiple sets of the leg extension on repetition maximum performance (RM), fatigue resistance index (FRI), and muscle soreness (MS). Study design: Quasi-experimental clinical trial. Methods: Twenty trained men participated in this study (30.35 ± 6.56 years, 1.77 ± 0.05 cm, 87.70 ± 7.6 kg) and attended seven sessions with 48 h between sessions, (one familiarization session, two 10-RM test and retest sessions, and four experimental sessions). The four experimental sessions were performed in random order and included: agonist foam rolling (AFR), antagonist foam rolling (ANTFR), agonist/antagonist foam rolling (A/ANTFR), and traditional control (TP, without foam rolling). All sessions consisted of three sets for maximal repetitions with a 10-RM load for the leg extension. In the AFR and ANTFR sessions, there was a 120 s rest interval between sets, during which FR was done for the agonists or antagonists, respectively. In the A/ANTFR protocol, there was a 120 s rest interval between sets, during which FR was done for the agonists and antagonists. In the traditional protocol (TP), there was a 120 s passive rest interval between sets. Results: Regarding the total training volume (TTV), significant differences were noted between sessions (F3,57 = 11.014, p = 0.0001). The AFR, ANTFR, and A/ANTFR sessions had significantly higher TTV versus the TP (p &lt, 0.05). Regarding the FRI, significant differences were noted between sessions (F3,57 = 2917, p = 0.042). A significantly higher fatigue index was shown for the ANTFR and AFR sessions versus the TP (p &lt, 0.05). Regarding the total number of repetitions, significant differences were noted between sessions (F3,57 = 11.086, p = 0.0001). The total number of repetitions was significantly higher in the A/ANTFR, ANTFR, and AFR versus the TP session (p &lt, 0.05). MS was significantly lower in the A/ANTFR, ANTFR, and AFR sessions versus the TP session (p &lt, 0.05). Conclusion: In conclusion, foam rolling between sets for the agonist or antagonist separately or in succession, resulted in greater neuromuscular performance and higher fatigue indices, as well as reducing the perception of acute muscle soreness.

The purpose of this study was to examine the influence of rest period duration (1 vs. 3 minute between sets) on acute hormone responses to a high-intensity and equal volume bench press workout. Ten resistance-trained men (25.2 ± 5.6 years; 78.2 ± 5.7 kg; 176.7 ± 5.4 cm; bench press relative strength: 1.3 ± 0.1 kg per kilogram of body mass) performed 2 bench press workouts separated by 1 week. Each workout consisted of 5 sets of 3 repetitions performed at 85% of 1 repetition maximum, with either 1- or 3-minute rest between sets. Circulating concentrations of total testosterone (TT), free testosterone (FT), cortisol (C), testosterone/cortisol ratio (TT/C), and growth hormone (GH) were measured at preworkout (PRE), and immediately (T0), 15 minutes (T15), and 30 minutes (T30) postworkout. Rating of perceived exertion was recorded before and after each set. For TT, both rest lengths enhanced all postexercise verifications (T0, T15, and T30) compared with PRE, with 1 minute showing decreases on T15 and T30 compared with T0. For FT, both 1- and 3-minute rest protocols triggered augmentations on distinct postexercise moments (T0 and T15 for 1 minute; T15 and T30 for 3-minute) compared with PRE. The C values did not change throughout any postexercise verification for either rests. The TT/C ratio was significantly elevated for both rests in all postexercise moments compared with PRE. Finally, GH values did not change for both rest lengths. In conclusion, although both short and long rest periods enhanced acute testosterone values, the longer rest promoted a long-lasting elevation for both TT and FT.

This study evaluated the effect of ischemic preconditioning (IPC) on resistance exercise performance in the lower limbs. Thirteen men participated in a randomized crossover design that involved 3 separate sessions (IPC, PLACEBO, and control). A 12-repetition maximum (12RM) load for the leg extension exercise was assessed through test and retest sessions before the first experimental session. The IPC session consisted of 4 cycles of 5 minutes of occlusion at 220 mm Hg of pressure alternated with 5 minutes of reperfusion at 0 mm Hg for a total of 40 minutes. The PLACEBO session consisted of 4 cycles of 5 minutes of cuff administration at 20 mm Hg of pressure alternated with 5 minutes of pseudo-reperfusion at 0 mm Hg for a total of 40 minutes. The occlusion and reperfusion phases were conducted alternately between the thighs, with subjects remaining seated. No ischemic pressure was applied during the control (CON) session and subjects sat passively for 40 minutes. Eight minutes after IPC, PLACEBO, or CON, subjects performed 3 repetition maximum sets of the leg extension (2-minute rest between sets) with the predetermined 12RM load. Four minutes after the third set for each condition, blood lactate was assessed. The results showed that for the first set, the number of repetitions significantly increased for both the IPC (13.08 ± 2.11; p = 0.0036) and PLACEBO (13.15 ± 0.88; p = 0.0016) conditions, but not for the CON (11.88 ± 1.07; p > 0.99) condition. In addition, the IPC and PLACEBO conditions resulted insignificantly greater repetitions vs. the CON condition on the first set (p = 0.015; p = 0.007) and second set (p = 0.011; p = 0.019), but not on the third set (p = 0.68; p > 0.99). No difference (p = 0.465) was found in the fatigue index and lactate concentration between conditions. These results indicate that IPC and PLACEBO IPC may have small beneficial effects on repetition performance over a CON condition. Owing to potential for greater discomfort associated with the IPC condition, it is suggested that ischemic preconditioning might be practiced gradually to assess tolerance and potential enhancements to exercise performance.

The aim of this study was to investigate the acute effects of different interset rest intervals on performance of single- and multijoint exercises with near-maximal loads. Fifteen trained men (26.40 ± 4.94 years, 79.00 ± 7.10 kg, 176.6 ± 6.06 cm, 11.80 ± 2.47% body fat, and bench press relative strength: 1.26 ± 0.19 kg·kg of body mass) performed eight sessions (2 exercises × 4 interset rest intervals); each consisting of 5 sets with a 3RM load. The exercises tested were the machine chest fly (MCF) for the single-joint exercise and the barbell bench press (BP) for the multi-joint exercise with 1, 2, 3, and 5 minutes of rest between sets. The results indicated that for the MCF, significantly higher total number of repetitions were completed for the 2- (12.60 ± 2.35 reps; p = 0.027), 3- (13.66 ± 1.84 reps; p = 0.001), and 5-minute (12.93 ± 2.25 reps; p = 0.001) vs. the 1-minute (10.33 ± 2.60 reps) protocol. For the BP, a significantly higher total number of repetitions were completed for 3- (11.66 ± 2.79 reps; p = 0.002) and 5-minute (12.93 ± 2.25 reps; p = 0.001) vs. the 1-minute protocol (7.60 ± 3.52 reps). In addition, subjects completed significantly higher total number of repetitions for the 5-minute (12.93 ± 2.25 reps; p = 0.016) vs. 2-minute (9.53 ± 3.11 reps) protocol. Both exercises presented similar and progressive reductions in repetition performance for all rest protocols along the 5 sets, starting as soon as the second set for the shorter 1-minute rest protocol. In conclusion, to maintain the best consistency in repetition performance, rest intervals of 2 minutes between sets are sufficient for the MCF and 3-5 minutes for the BP. Thus, it appears that longer acute recovery time is needed for a multijoint (core) exercise such as the BP vs. a single-joint (assistance) exercise such as the MCF.

The purpose of this study was to analyze and compare heart rate (HR), heart rate variability (HRV), and blood pressure (BP) responses during and after circuit resistance training with 1 min. (CIR1) vs. 2 min. (CIR2) rest intervals between exercises in liver cirrhosis patients. 10 patients (7 women, 3 men) participated in 2 experimental sessions (CIR1 and CIR2) in random order. Each experimental session consisted of 6 exercises performed for 3 sets of 10 repetitions with 70% of the 10-RM load. The only difference between experimental sessions was taking either 1 min. (CIR1) or 2 min. (CIR2) of rest between exercises. Prior and during each session, BP, HR and HRV (beat-to-beat intervals) were assessed. Training efficiency were significant higher for CIR1 when compared to CIR2, since same total training volume was performed in less time. Both protocols elicited significant changes in HR, SBP, and SampEn. Based on the ∆HR and ∆IRR between protocols, higher cardiovascular stress was observed for CIR1 vs. CIR2. However, the patients presented a similar recovery pattern between experimental sessions, and did not present significant alterations in the HRV at 60 min post-workout. In summary, the fast adjustment of autonomic modulation in HRV and BP suggests that circuit resistance training with 1-min or 2-min rest intervals between exercises elicits typical cardiovascular responses in liver cirrhosis patients.

Objective: The purpose of this investigation was to compare different rest period lengths between consecutive one maximum repetition bench press attempts on performance and ratings of perceived exertion. Method: Eighteen trained men (27.95 ± 4.25 years; 81.00 ± 9.21 kg; 174.62 ± 3.34 cm; bench press relative strength 1.33 ± 0.11 kg/kg of body mass) participated in three randomly ordered sessions that required two consecutive one maximum repetition bench press attempts with 20, 40, or 60-s rest between attempts. Results: The Cochran Q analysis showed no significant differences in the ability to successfully perform a second one maximum repetition attempt with 20, 40, or 60-s rest between attempts (p = 0.882). Specifically, no significant differences were found in the successful completion of the first and second attempts for the 20-s (p = 0.317), 40-s (p = 0.083), and 60-s (p = 0.157) trials, respectively. Briefly, for both 20 and 60-s rest conditions Δ% = 88.88% of subjects successfully performed the second attempt and, for the 40-s protocol, only Δ% = 83.33% completed. For the pre and post-set ratings of perceived exertion, the shorter rest period (20-s) promoted significantly higher values compared to the longer rest periods (pre-set ratings of perceived exertion, p = 0.04; post-set ratings of perceived exertion, p = 0.023). Conclusions: The results of this study can be applied to recreationally trained individuals with the intent of generating a time-efficient process for conducting a valid and reliable one maximum repetition bench press assessment.

BACKGROUND The purpose of this study was to compare traditional strength training (TST) versus complex and contrast training (CCT) on sprint, change of direction speed (COD) and squat jump (SJ) in young male soccer players. METHODS Twenty-two soccer players (age: 18.4±0.4 years, body mass: 70.2±9.1 kg, height: 179.9±7.5 cm), were randomly assigned to one of two groups: TST (N.=12) and CCT (N.=10). The study was conducted using a randomized experimental design over an eight-week period. The participants assigned to the CCT group performed high-power exercises paired with high-velocity exercises. The participants assigned to the TST group performed resistance exercises in a straight-set forma. During the study period, sprint tests for 5, 10, 20 and 30 m split times, COD and SJ were applied. A two-way ANOVA was applied, and the alpha level was P

Miranda, H, Maia, MF, Paz, GA, de Souza, JAAA, Simao, R, Farias, DA, and Willardson, JM. Repetition performance and blood lactate responses adopting different recovery periods between training sessions in trained men. J Strength Cond Res 32(12): 3340-3347, 2018-The purpose of this study was to examine the effect of different recovery periods (24, 48, and 72 hours) between repeated resistance training (RT) sessions for the upper-body muscles on repetition performance and blood lactate responses in trained men. Sixteen recreationally trained men (age: 26.1 ± 3.1 years; height: 179 ± 4.5 cm; body mass: 82.6 ± 4.0 kg, 4.5 ± 2.2 years of RT experience) participated in this study. Eight repetition maximum (8RM) loads were determined for the bench press (BP), 30° incline bench press (BP30), and 45° incline bench press (BP45) exercises. To assess the effects of different recovery periods between repeated training sessions, 3 protocols were performed in randomized order, including 24 hours (P24), 48 hours (P48), and 72 hours (P72). Each RT session consisted of performing 4 repetition maximum sets of the BP, BP30, and BP45 with 8RM loads and 2-minute rest intervals between sets. Blood lactate levels were measured presession (PRE), immediately postsession (POST), 3 minutes postsession (P3), and 5 minutes postsession (P5). For the P24 protocol, significant decreases in repetition performance were found between sessions for the BP, BP30, and BP45 exercises, respectively. When considering session 2 only, the total work (repetition × sets) was significantly higher under P48 and P72 compared with P24 for the BP30 and BP45 exercises. Blood lactate levels (i.e., POST, P3, and P5) significantly increased for session 2 under the P24 compared with the P48 and P72 protocols, respectively. Therefore, coaches and practitioners who need to accomplish a higher training volume for the upper-body muscles should adopt recovery periods longer than 24 hours between sessions that train the same or similar muscle groups.

Recent evidence suggests that exercising the antagonist musculature acutely enhances subsequent performance for the agonist musculature. The purpose of this study was to examine the effects of different rest intervals between sets for exercises that involve antagonistic muscle groups, a technique referred to as antagonist paired sets (APS). Fifteen recreationally trained men were tested for knee extension (KE) exercise performance, with or without previous knee flexion (KF) exercise for the antagonist musculature. The following protocols were performed in random order with 10 repetition maximum loads for the KF and KE exercises: (a) traditional protocol (TP)-1 set of KE only to repetition failure; (b) paired sets with minimal allowable rest (PMR)-1 set of KF followed immediately by a set of KE; (c) P30-30-second rest between paired sets of KF and KE; (d) P1-1-minute rest between paired sets; (e) P3-3-minute rest between paired sets; and (f) P5-5-minute rest between paired sets. The number of repetitions performed and electromyographic (EMG) activity of vastus lateralis, vastus medialis (VM), and rectus femoris (RF) muscles were recorded during the KE set in each protocol. It was demonstrated that significantly greater KE repetitions were completed during the PMR, P30, and P1 protocols vs. the TP protocol. Significantly greater EMG activity was demonstrated for the RF muscle during the KE exercise in the PMR and P30 vs. the TP, P3, and P5, respectively. In addition, significantly greater EMG activity was demonstrated for the VM muscle during the PMR vs. all other protocols. The results of this study indicate that no rest or relatively shorter rest intervals (30 seconds and 1 minute) between APS might be more effective to elicit greater agonist repetition enhancement and muscle activation.

It has been hypothesized that lifting light loads to muscular failure will activate the full spectrum of MUs and thus bring about muscular adaptations similar to high-load training. The purpose of this study was to investigate EMG activity during low- versus high-load training during performance of a multi-joint exercise by well-trained subjects.Employing a within-subject design, 10 young, resistance-trained men performed sets of the leg press at different intensities of load: a high-load (HL) set at 75% of 1-RM and a low-load (LL) set at 30% of 1-RM. The order of performance of the exercises was counterbalanced between participants, so that half of the subjects performed LL first and the other half performed HL first, separated by 15 min rest. Surface electromyography (EMG) was used to assess mean and peak muscle activation of the vastus medialis, vastus lateralis, rectus femoris, and biceps femoris.Significant main effects for trials and muscles were found (p0.01). Significantly greater peak EMG activity was found during the HL set (M = 177.3, SD = 89.53) compared to the LL set (M = 137.73, SD = 95.35). Significantly greater mean EMG activity was found during the HL set (M = 63.7, SD = 37.23) compared to the LL set (M = 41.63, SD = 28.03).Results indicate that training with a load of 30% 1-RM to momentary muscular failure does not maximally activate the full motor unit pool of the quadriceps femoris and hamstrings during performance of multi-joint lower body exercise.

The purpose of the study was to compare core muscle activation of the tradition prone plank with a modified version performed with a long-lever and posterior-tilt using surface electromyography. To further determine if a specific component of this modified plank was more effective than the other in enhancing muscle activity, the plank with a long lever and the plank with a posterior pelvic tilt were studied individually. Nineteen participants performed all four variations of the plank for 30 seconds in a randomized order with 5-minute rest between exercise bouts. Compared to the traditional prone plank, the long-lever posterior-tilt plank displayed a significantly increased activation of the upper rectus abdominis (p < 0.001), lower abdominal stabilizers (p < 0.001), and external oblique (p < 0.001). The long-lever plank showed significantly greater activity compared to the traditional plank in the upper rectus abdominis (p = 0.015) and lower abdominal stabilizers (p < 0.001), while the posterior tilt plank elicited greater activity in the external oblique (p = 0.028). In conclusion, the long-lever posterior-tilt plank significantly increases muscle activation compared to the traditional prone plank. The long-lever component tends to contribute more to these differences than the posterior-tilt component.

A growing body of research has demonstrated the effectiveness of exercise (low-intensity resistance training, walking, cycling) combined with blood flow restriction (BFR) for increased muscular strength and hypertrophy. The BFR is achieved via the application of external pressure over the proximal portion of the upper or lower extremities. The external pressure applied is sufficient to maintain arterial inflow while occluding venous outflow of blood distal to the occlusion site. With specific reference to low-intensity resistance training, the ability to significantly increase muscle strength and hypertrophy when combined with BFR is different from the traditional paradigm, which suggests that lifting only higher intensity loads increases such characteristics. The purpose of this review was to discuss the relevant literature with regard to the type and magnitude of acute responses and chronic adaptations associated with BFR exercise protocols vs. traditional non-BFR exercise protocols. Furthermore, the mechanisms that stimulate such responses and adaptations will be discussed in the context of neural, endocrine, and metabolic pathways. Finally, recommendations will be discussed for the practitioner in the prescription of exercise with BFR.

Figueiredo, T, Willardson, JM, Miranda, H, Bentes, CM, Machado Reis, V, Freitas de Salles, B, and Simao, R. Influence of rest interval length between sets on blood pressure and heart rate variability after a strength training session performed by prehypertensive men. J Strength Cond Res 30(7): 1813-1824, 2016-The purposes of this study were to compare the effects of 2 different rest interval lengths between sets and exercises during strength training (ST) on blood pressure (BP) and heart rate variability (HRV) in prehypertensive trained men, and to verify how HRV influences BP. Eleven volunteer subjects (age: 26.1 ± 3.6 years; body mass: 74.1 ± 7.9 kg; height: 172.1 ± 4.1 cm; % body fat: 18.3 ± 6.3; ST experience: 1.7 ± 0.8 years) participated in this study. After assessing one repetition maximum (1RM) loads for the free weight bench press, lat pull-down, shoulder press, biceps curl, triceps extension, leg press, leg extension, and leg curl exercises; subjects performed 2 sessions with different rest intervals between sets and exercises in random order and 72 hours apart. Each ST session consisted of performing 3 sets of eight to 10 repetitions at 70% of a 1RM for each exercise, with either 1-minute (sequence 1 [SEQ1]) or 2-minute (sequence 2 [SEQ2]) rest intervals between sets and exercises, respectively. Before and after each session, BP and HRV (low frequency band, high frequency [HF] band, and square root of the mean squared difference of successive RR-interval index) were tracked for 60 minutes. The results demonstrated a postexercise hypotensive response (PEH) after both rest interval conditions (p ≤ 0.05). Additionally, increases in cardiac stress were noted after SEQ1, with a greater withdrawal in parasympathetic activity vs. baseline as noted in the HF band at 1-, 10-, and 20-minute postexercise (p ≤ 0.05). These results indicate that both sequences provided an effective stimulus for a PEH. Therefore, strength and conditioning professionals may prescribe 1- or 2-minute rest between sets and exercises when the goal is to reduce BP after training sessions. However, resting 1 minute between sets and exercises was associated with greater cardiac stress, and so this may necessitate prescription of longer rest intervals between sets and exercises when working with individuals who have been diagnosed with cardiovascular dysfunction.

The purpose of this study was to determine the effects of supra-physiological doses of testosterone (TES) on membrane oxidation of activated human neutrophils in vitro using an innovative and sensitive technique: the real-time detection with the fluorescence probe C11-BODIPY(581/591). Methodological controls were performed with the lipid-soluble and powerful antioxidant astaxanthin at different neutrophil density cultures. Neutrophils from nine healthy young men (23.4 ± 2.5 years, 174.4 ± 7.0 cm height, and 78.3 ± 7.0 kg weight) were isolated and treated with 0.1 or 10 μM TES for 24 h and subsequently labeled with the free radical-sensitive probe C11-BODIPY(581/591) for monitoring membrane oxidation after neutrophil activation with phorbol-12-myristate-13-acetate (PMA). First-order exponential decay kinetic indicated that both 0.1 and 10 μM TES severely increased baseline membrane oxidation in non-activated human neutrophils (compared to control). However, similar kinetics of membrane oxidation were observed in control and 0.1 μM TES-treated neutrophils after PMA activation, whereas chemical activation did not alter the baseline higher rates of membrane oxidation in 10 μM TES-treated neutrophils. The data presented here support the hypothesis that TES exerts distinct effects on the membrane oxidation of human neutrophils, depending on its dose (here, 10(2) to 10(4)-fold higher than physiological levels in men) and on PMA activation of the oxidative burst. Furthermore, this paper also presents an innovative application of the free radical-sensitive probe C11-BODIPY(581/591) for monitoring (auto-induced) membrane oxidation as an important parameter of viability and, thus, responsiveness of immune cells in inflammatory processes.

The purpose of this study was to compare 4 different loading schemes for the free weight bench press, wide grip front lat pull-down, and free weight back squat to determine the extent of progressive load reductions necessary to maintain repetition performance. Thirty-two recreationally trained women (age = 29.34 ± 4.58 years, body mass = 59.61 ± 4.72 kg, height = 162.06 ± 4.04 cm) performed 4 resistance exercise sessions that involved 3 sets of the free weight bench press, wide grip front lat pull-down, and free weight back squat, performed in this exercise order during all 4 sessions. Each of the 4 sessions was conducted under different randomly ordered loading schemes, including (a) a constant 10 repetition maximum (RM) load for all 3 sets and for all 3 exercises, (b) a 5% reduction after the first and second sets for all the 3 exercises, (c) a 10% reduction after the first and second sets for all the 3 exercises, and (d) a 15% reduction after the first and second sets for all the 3 exercises. The results indicated that for the wide grip front lat pull-down and free weight back squat, a 10% load reduction was necessary after the first and second sets to accomplish 10 repetitions on all the 3 sets. For the free weight bench press, a load reduction between 10 and 15% was necessary; specifically, a 10% reduction was insufficient and a 15% reduction was excessive, as evidenced by significantly >10 repetitions on the second and third sets for this exercise (p ≤ 0.05). In conclusion, the results of this study indicate that a resistance training prescription that involves 1-minute rest intervals between multiple 10RM sets does require load reductions to maintain repetition performance. Practitioners might apply these results by considering an approximate 10% load reduction after the first and second sets for the exercises examined, when training women of similar characteristics as in this study.

Machado, M, Pereira, R, and Willardson, JM. Short intervals between sets and individuality of muscle damage response. J Strength Cond Res 26(11): 2946–2952, 2012—This study examined creatine kinase (CK) activity after resistance exercise sessions in subjects classified as high (HiR), medium (MeR), or low responders (LoR). Two resistance exercise sessions were performed that each involved 4 sets of the biceps curl at 85% of a 1 repetition maximum (1RM) and either 1- or 3-minute rest intervals between sets. High responders and MeR demonstrated significantly greater CK activity after the 1-minute session vs. the 3-minute session. Therefore, the HiR and MeR subjects exhibited less tolerance to resting 1 minute between sets, whereas the CK activity was not significantly different between rest intervals for the LoR subjects. The application of these findings indicates the need to vary the length of the rest interval between sets with the understanding that individuals exhibit varying recuperative abilities and some might be less tolerant of shorter rest intervals between sets.

The purpose of this study was to compare repetition maximum performance and ratings of perceived exertion during resistance exercise sessions conducted at a low intensity (i.e., 20 RM) and in different exercise orders. Twenty-one recreationally trained men performed two total body resistance exercise sessions in opposite orders; each exercise was performed for three sets with 2 minutes passive rest between sets and exercises. The results indicated significantly greater total repetitions for each exercise when performed near the beginning of a sequence and for the first set of each exercise, irrespective of the sequence. The ratings of perceived exertion, however, were not significantly different between sequences. In conclusion, repetition maximum performance for resistance exercise sessions conducted at a low intensity is significantly different based on exercise order. Therefore, when performing high repetitions with relatively low intensity loads, exercises should be prioritized based on individual needs and sports-specific movement patterns for greater volume and potential for the desired neuromuscular adaptations.

In the current study, we examined the relationship between serum creatine kinase (CK) activity following upper body resistance exercise with a 1- or 3-min rest between sets. Twenty men performed two sessions, each consisting of four sets with a 10-repetition maximum load. The results demonstrated significantly greater volume for the 3-min condition (M = 4,156 kg, SD = 867, for 3 min; vs. M = 3,503 kg, SD = 759, for 1 min; p < .001), with no significant differences in delta CK activity between conditions (p = .574). Nevertheless, there was a weak correlation between the delta CK activity and total volume of exercise completed (r = .55 with a 1-min rest, and r =.45 with a 3-min rest). Therefore, the volume following upper body resistance exercise correlates weakly with serum CK levels, irrespective of rest interval length between sets.

The purpose of this study was to compare repetition performance and rating of perceived exertion (RPE) with 1-, 3-, or 5-minute rest intervals between sets of multi and single-joint resistance exercises. Fifteen resistance trained men (23.6 ± 2.64 years, 76.46 ± 7.53 kg, 177 ± 6.98 cm, bench press [BP] relative strength: 1.53 ± 0.25 kg·kg(-1) body mass) completed 12 sessions (4 exercises × 3 rest intervals), with each session involving 5 sets with 10 repetition maximum loads for the free weight BP, machine leg press (LP), machine chest fly (MCF), and machine leg extension (LE) exercises with 1-, 3-, 5-minute rest intervals between sets. The results indicated significantly greater BP repetitions with 3 or 5 minutes vs. 1 minute between sets (p ≤ 0.05); no significant difference was evident between the 3- and 5-minute rest conditions. For the other exercises (i.e., LP, MCF, and LE), significant differences were evident between all rest conditions (1 < 3 < 5; p ≤ 0.05). For all exercises, consistent declines in repetition performance (relative to the first set) were observed for all rest conditions, starting with the second set for the 1-minute condition and the third set for the 3- and 5-minute conditions. Furthermore, significant increases in RPE were evident over successive sets for both the multi and single-joint exercises, with significantly greater values for the 1-minute condition. In conclusion, both multi and single-joint exercises exhibited similar repetition performance patterns and RPE, independent of the rest interval length between sets.

The purpose of the current study was to compare different rest interval durations on upper and lower body strength. Thirty-six recreationally trained men were randomly assigned to 1 min (G1; n=12), 3 min (G3; n=12) or 5 min (G5; n=12) rest interval groups. Each group performed the same resistance training program. Maximal strength was assessed at baseline, mid-point (8 weeks) and post-training (16 weeks) for the bench press and leg press exercises. For the bench press, significant increases were demonstrated within G3 and G5 at 8 weeks and at 16 weeks versus baseline (p

The purpose of the current study was to compare serum creatine kinase (CK) and lactate dehydrogenase (LDH) concentrations at multiple time points after resistance exercise sessions that incorporated different rest intervals between sets and exercises. Twenty untrained men (18.65+/-0.49 years, 68.30+/-7.98 kg, and 174.4+/-4.80 cm) performed 2 resistance exercise sessions (i.e., 3 sets with 80% 1 repetition maximum for 5 upper-body exercises) with either 1-minute (SEQ1) or 3-minute (SEQ3) rest between sets and exercises. For each session, CK and LDH concentrations were measured before exercise (PRE) and 24, 48, and 72 hours after exercise (24P, 48P, and 72P). Subjects lifted a 24% greater (p

When performing consecutive sets of a resistance exercise, maintaining performance within a specified repetition range has been shown to be essential for achieving muscular adaptations conducive to different training goals. However, maintaining repetition performance can be difficult when using shorter rest intervals between sets (i.e.,or = 1 min), which may require load reductions. Therefore, the purpose of the current study was to compare repetition performance when keeping the load constant or reducing the load by different percentages during a lower-body workout. Ten repetition maximum (10RM) loads were established for the back squat, leg curl, and leg extension exercises. Subjects performed 4 workouts under the following load conditions: (a) constant load for all sets, (b) 5% load reduction after each set, (c) 10% load reduction after each set, and (d) 15% load reduction after each set. Pairwise comparisons indicated that, when averaged across sets, significantly fewer repetitions were accomplished for the back squat and leg curl within the constant condition vs. the 15% condition (p0.05). Conversely, for the leg extension, there were no significant differences in the repetitions accomplished between conditions (p0.05). Pairwise comparisons also indicated that, when averaged across exercises, significantly fewer repetitions were accomplished for set 3 within the constant, 5%, and 10% conditions vs. the 15% condition (p0.05). In summary, the back squat and leg curl required 15% load reductions per set to maintain repetition performance. Conversely, load reductions were not necessary for the leg extension.

Purpose:The purpose of this study was to evaluate the effects of caffeine ingestion before a resistance exercise session on markers of muscle damage (CK, LDH, ALT, AST) and leukocyte levels.Methods:Fifteen soccer athletes completed two resistance exercise sessions that differed only in the ingestion of caffeine or a placebo preworkout.Results:CK concentration increased significantly following the caffeine session (415.8 ± 62.8 to 542.0 ± 73.5) and the placebo session (411.5 ± 43.3 to 545.8 ± 59.9), with no significant differences between sessions. Similarly, LDH concentration increased significantly following the caffeine session (377.5 ± 18.0 to 580.5 ± 36.1) and the placebo session (384.8 ± 13.9 to 570.4 ± 36.1), with no significant differences between sessions. Both sessions resulted in significant increases in the total leukocyte count (caffeine = 6.24 ± 2.08 to 8.84 ± 3.41; placebo = 6.36 ± 2.34 to 8.77 ± 3.20), neutrophils (caffeine = 3.37 ± 0.13 to 5.15 ± 0.28; placebo = 3.46 ± 0.17 to 5.12 ± 0.24), lymphocytes (caffeine = 2.19 ± 0.091 to 2.78 ± 0.10; placebo = 2.17 ± 0.100 to 2.75 ± 0.11), and monocytes (caffeine = 0.53 ± 0.02 to 0.72 ± 0.06; placebo = 0.56 ± 0.03 to 0.69 ± 0.04), with no significant differences between sessions.Conclusion:Ingestion of caffeine at 4.5 mg⋅kg-1 did not augment markers of muscle damage or leukocyte levels above that which occurs through resistance exercise alone.

Purpose:To compare core muscle activity during resistance exercises performed on stable ground vs. the BOSU Balance Trainer.Methods:Twelve trained men performed the back squat, dead lift, overhead press, and curl lifts. The activity of the rectus abdominis, external oblique abdominis, transversus abdominis/internal oblique abdominis, and erector spinae muscles was assessed. Subjects performed each lift under three separate conditions including standing on stable ground with 50% of a 1-RM, standing on a BOSU Balance Trainer with 50% of a 1-RM, and standing on stable ground with 75% of a 1-RM.Results:Significant differences were noted between the stable 75% of 1-RM and BOSU 50% of 1-RM conditions for the rectus abdominis during the overhead press and transversus abdominis/internal oblique abdominis during the overhead press and curl (P < .05). Conversely, there were no significant differences between the stable 75% of 1-RM and BOSU 50% of 1-RM conditions for the external obliques and erector spinae across all lifts examined. Furthermore, there were no significant differences between the BOSU 50% of 1-RM and stable 50% of 1-RM conditions across all muscles and lifts examined.Conclusions:The current study did not demonstrate any advantage in utilizing the BOSU Balance Trainer. Therefore, fitness trainers should be advised that each of the aforementioned lifts can be performed while standing on stable ground without losing the potential core muscle training benefits.

The purpose of this study was to compare squat strength gains and volume components when resting 2 minutes vs. 4 minutes between sets over multiple mesocycles. After the first squat 1 repetition maximum, 15 trained men were matched and randomly assigned to either a 2-minute (n = 7) or a 4-minute (n = 8) rest interval group. Each group performed the same training program, with the only difference being the length of the rest interval between sets. Subjects performed two squat workouts per week; one was labeled as Heavy and the other was labeled as Light. The squat workouts varied in the intensity, number of sets, and repetitions performed per set in a nonlinear periodized manner throughout each mesocycle. Differences in strength gains and volume components (the load utilized per set, the repetitions performed per set, the intensity per set, and the volume performed per workout) were compared between groups. Both groups demonstrated large strength gains; however, these differences were not significant between groups (P = 0.47). During all mesocycles, the 4-minute group demonstrated significantly higher total volumes for the Heavy workouts (P < 0.05). The findings of the present study indicate that large squat strength gains can be achieved with a minimum of 2 minutes' rest between sets, and little additional gains are derived from resting 4 minutes between sets. Therefore, athletes attempting to achieve specific volume goals may need longer rest intervals initially but may later adapt so that shorter rest intervals can be utilized without excessive fatigue, leaving additional time to focus on other conditioning priorities.

Core stability exercises have become main stream, with rehabilitative methodologies now being applied to healthy athletes. A popular trend has been to perform resistance exercises on unstable equipment. However, resistance exercises performed on unstable equipment are not effective for the development of core strength and power due to the light loads, long tension times, and low velocities that characterize such lifts. Based on the current literature, performance of groundbased free weight movements might be better for the development of core strength and power due to the force, velocity, and core stabilizing requirements that are similar to the demands of sports skills.

In recent years, fitness practitioners have increasingly recommended core stability exercises in sports conditioning programs. Greater core stability may benefit sports performance by providing a foundation for greater force production in the upper and lower extremities. Traditional resistance exercises have been modified to emphasize core stability. Such modifications have included performing exercises on unstable rather than stable surfaces, performing exercises while standing rather than seated, performing exercises with free weights rather than machines, and performing exercises unilaterally rather than bilaterally. Despite the popularity of core stability training, relatively little scientific research has been conducted to demonstrate the benefits for healthy athletes. Therefore, the purpose of this review was to critically examine core stability training and other issues related to this topic to determine useful applications for sports conditioning programs. Based on the current literature, prescription of core stability exercises should vary based on the phase of training and the health status of the athlete. During preseason and in-season mesocycles, free weight exercises performed while standing on a stable surface are recommended for increases in core strength and power. Free weight exercises performed in this manner are specific to the core stability requirements of sports-related skills due to moderate levels of instability and high levels of force production. Conversely, during postseason and off-season mesocycles, Swiss ball exercises involving isometric muscle actions, small loads, and long tension times are recommended for increases in core endurance. Furthermore, balance board and stability disc exercises, performed in conjunction with plyometric exercises, are recommended to improve proprioceptive and reactive capabilities, which may reduce the likelihood of lower extremity injuries.

The purpose of this study was to compare blood pressure and heart rate variability (HRV) responses in trained men after strength training (ST) sessions with loads of 60, 70, and 80% of a 1 repetition maximum (1RM). Eleven men (age: 26.1 ± 3.6 years; body mass: 74.1 ± 8.1 kg; height: 172.0 ± 4.0 cm; body mass index: 25.0 ± 1.96 kg·m(-2); %G: 18.3 ± 6.4) with at least 6-month ST experience participated in this study. After assessment of 1RM loads for the bench press (BP), lat pull-down (LPD), shoulder press (SP), biceps curl (BC), triceps extension (TE), leg press (LP), leg extension (LE), and leg curl (LC), subjects performed 3 experimental sessions in random order. During each experimental session, subjects performed 3 sets of 8-10 repetitions at 60, 70, or 80% of 1RM loads, with 2-minute rest intervals between sets and exercises. All experimental sessions were performed in the following exercise order: BP, LPD, SP, BC, TE, LP, LE, and LC. Before and for 1 hour after each experimental session, blood pressure and HRV were tracked. The results demonstrated a greater duration of postexercise hypotension (PEH) after the 70% of 1RM session vs. the 60 or 80% of 1RM session. These results indicate that the load/volume associated with completion of 8-10 repetitions at 70% of 1RM load may provide the best stimulus for the PEH response when compared with training with a 60 or 80% of 1RM loads. In conclusion, strength and conditioning professionals may prescribe exercises with 60, 70, and 80% of 1RM loads if the intent is to elicit an acute decrease in blood pressure after an ST session; however, 70% of 1RM provides a longer PEH.

Low-intensity resistance exercise (RE) combined with blood flow restriction (BFR) has been shown to promote similar increases in strength and hypertrophy as traditional high-intensity RE without BFR. However, the effect of BFR on the acute postexercise hypotensive response has received limited examination. Therefore, the purpose of this study was to compare high-intensity exercise (HIE) vs. low-intensity RE with BFR on the postexercise hypotensive response in normotensive young subjects. Fifteen men (age: 23.4 ± 3.4 years) performed the following 2 experimental protocols in randomized order: (a) 3 sets of biceps curls (BCs) at 80% of 1 repetition maximum (RM) and 120-second rest between sets (HIE protocol) and (b) 3 sets of BCs at 40% of 1RM with BFR and 60-second rest between sets. Analysis of systolic blood pressure (SBP) and diastolic blood pressure (DBP) was conducted for 60 minutes after both protocols. The values for SBP, DBP, and mean blood pressure (MBP) at baseline and postexercise were not significantly different between the HIE vs. the BFR protocol. However, within the BFR protocol, significant decreases (p

This study aimed to examine the effect of caffeine on hemodynamics after a resistance exercise session. Fifteen subjects completed two randomly ordered experimental resistance exercise sessions 45 min after the ingestion of either caffeine (4 mg.kg(-1)) or placebo. Systolic (SBP), diastolic (DBP) and mean (MAP) blood pressures were measured before consuming caffeine; SBP, DBP, MAP, heart rate, stroke volume, cardiac output and peripheral vascular resistance (PVR) were measured immediately before and after each of the sessions; SBP, DBP and MAP were measured for 9 hours after sessions. Caffeine increased (p < 0.05) pre-exercise DBP and MAP. In caffeine and placebo conditions significant decreases (p < 0.05) were noted in SBP, MAP, and PVR between the pre- and post-exercise time points. Notwithstanding, the mean values for SBP, DBP and MAP during the 9 h of post-exercise monitoring were increased (p < 0.05) for the caffeine. In conclusion, the cardiovascular effects of caffeine are different over the post-exercise period after resistance exercise in normotensive young adults.

The purpose of this study was to compare different rest intervals between sets on repetition consistency and ratings of perceived exertion (RPE) during consecutive bench press sets with an absolute 3RM (3 repetition maximum) load. Sixteen trained men (23.75 ± 4.21 years; 74.63 ± 5.36 kg; 175 ± 4.64 cm; bench press relative strength: 1.44 ± 0.19 kg/kg of body mass) attended 4 randomly ordered sessions during which 5 consecutive sets of the bench press were performed with an absolute 3RM load and 1, 2, 3, or 5 minutes of rest interval between sets. The results indicated that significantly greater bench press repetitions were completed with 2, 3, and 5 minutes vs. 1-minute rest between sets (p