Humberto Miranda

EFFECT OF TWO DIFFERENT REST PERIOD LENGTHS ON THE NUMBER OF REPETITIONS PERFORMED DURING RESISTANCE TRAINING

The purpose of this study was to compare the effects of 2 different rest period lengths during a resistance training session with the number of repetitions completed per set of each exercise, the volume completed over 3 sets of each exercise, and the total volume during a training session. Fourteen experienced, weight- trained men volunteered to participate in the study. All subjects completed 2 experimental training sessions. Both sessions consisted of 3 sets of 8 repetitions with an 8 repetition maximum resistance of 6 upper body exercises performed in a set manner (wide grip lat pull-down, close grip pull-down, machine seated row, barbell row lying on a bench, dumbbell seated arm curl, and machine seated arm curl). The 2 experimental sessions differed only in the length of the rest period between sets and exercises: 1 session with a 1-minute and the other with a 3-minute rest period. For all exercises, results demonstrate a significantly lower total number of repetitions for all 3 sets of an exercise when 1-minute rest periods were used (p ≤ 0.05). The 3- and 1-minute protocols both resulted in a significant decrease from set 1 to set 3 in 4 of the 6 exercises (p ≤ 0.05), whereas the 1- minute protocol also demonstrated a significant decrease from set 1 to set 2 in 2 of the 6 exercises (p ≤ 0.05). The results indicate that, during a resistance training session composed of all upper body exercises, 1-minute rest periods result in a decrease in the total number of repetitions performed compared with 3-minute rest periods between sets and exercises.

Anti-Inflammatory Effects of Low-Level Light Emitting Diode Therapy on Achilles Tendinitis in Rats

The present study investigated the effects of low‐level light emitting diode (LED) therapy (880 ± 10 nm) on inflammatory process in a experimental model of Achilles tendinitis induced by collagenase.

Creatine kinase and lactate dehydrogenase responses after upper-body resistance exercise with different rest intervals.

Rodrigues, BM, Dantas, E, de Salles, BF, Miranda, H, Koch, AJ, Willardson, JM, and Simão, R. Creatine kinase and lactate dehydrogenase responses after upper-body resistance exercise with different rest intervals. J Strength Cond Res 24(6): 1657-1662, 2010-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 < 0.05) volume load during SEQ3 than during SEQ1. Within SEQ1, significant differences in CK concentrations were demonstrated between most time points, except between 24P and 72P. Similarly, within SEQ3, significant differences in CK concentrations were demonstrated between most time points, except between 24P and 72P and between 48P and 72P. The CK concentrations were highest at 48P for both sessions. When the CK concentrations were compared between SEQ1 and SEQ3, no significant differences were demonstrated at any time point. Within SEQ1, a significant difference in LDH concentration was demonstrated between 48P and 72P. Within SEQ3, significant differences in LDH concentrations were demonstrated between PRE and 24P and between PRE and 48P. The LDH concentrations were highest at 72P for SEQ1 and at 24P for SEQ3. When the LDH concentrations were compared between SEQ1 and SEQ3, no significant differences were demonstrated at any time point. These results suggest that muscle damage was similar between rest intervals; however, the volume load completed to induce the muscle damage was significantly greater when 3-minute rest intervals were employed. Therefore, when considered relative to the volume load completed, 1-minute rest intervals during resistance exercise may invoke greater muscle damage.

Effects of linear vs. daily undulatory periodized resistance training on maximal and submaximal strength gains.

Miranda, F, Simão, R, Rhea, M, Bunker, D, Prestes, J, Leite, RD, Miranda, H, de Salles, BF, and Novaes, J. Effects of linear vs. daily undulatory periodized resistance training on maximal and submaximal strength gains. J Strength Cond Res 25(7): 1824-1830, 2011—The objective of this study was to verify the effect of 2 periodized resistance training (RT) methods on the evolution of 1-repetition maximum (1RM) and 8RM loads. Twenty resistance trained men were randomly assigned to 2 training groups: linear periodization (LP) group and daily undulating periodization (DUP) group. The subjects were tested at baseline and after 12 weeks for 1RM and 8RM loads in leg press (LEG) and bench press (BP) exercises. The training program was performed in alternated sessions for upper (session A: chest, shoulder and triceps) and lower body (session B: leg, back and biceps). The 12-week periodized training was applied only in the tested exercises, and in the other exercises, 3 sets of 6-8RM were performed. Both groups exhibited significant increases in 1RM loads on LEG and BP, but no statistically significant difference between groups was observed. The same occurred in 8RM loads on LEG and BP. However, DUP group presented superior effect size (ES) in 1RM and 8RM loads for LEG and BP exercises when compared to the LP group. In conclusion, periodized RT can be an efficient method for increasing the strength and muscular endurance in trained individuals. Although there was no statistically significant difference between periodization models, DUP promoted superior ES gains in muscular maximal and submaximal strength.

Strength increases in upper and lower body are larger with longer inter-set rest intervals in trained men

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<0.05). Additionally, for the bench press, G5 (98.2+/-3.7 kg) was significantly stronger than G1 (92.5+/-3.8 kg) at 16 weeks (p<0.05). For the leg press, significant increases were demonstrated within all groups at 8 weeks and at 16 weeks versus baseline (p<0.05). Additionally, for the leg press, G5 (290.8+/-23.5 kg) was significantly stronger than G1 (251.0+/-15.8 kg) at 8 weeks (p<0.01) and G3 (305.0+/-23.9 kg) and G5 (321.7+/-21.7 kg) were significantly stronger than G1 (276.7+/-10.7 kg) at 16 weeks (p<0.05). The findings of the current study indicate that utilising 3 or 5 min rest intervals between sets may result in significantly greater increases in upper and lower body strength beyond the initial weeks of training versus utilising 1-min rest intervals between sets.

Análise da freqüência cardíaca, pressão arterial e duplo-produto em diferentes posições corporais nos exercícios resistidos

Actualmente, los ejercicios resistidos (ER) vienen sufriendo una serie de investigaciones, debido a la importancia que tengan en el desenvolvimiento del acondicionamiento cardiorespiratorio y neuromuscular. Para la prescripcion de los ER, algunas variables deben ser monitoreadas, tales como frecuencia cardiaca (FC) y la presion arterial (PA). La asociacion entre la FC y PA provee los datos para obtener el doble producto (DP). Esas variables fueron utilizadas para analizar y comparar las respuestas hemodinamicas de supino sentado recto (SRS) y de supino acostado recto (SRD), siendo realizadas 10 repeticiones a 65% de una repeticion maxima (1RM). La amuestra estaba constituida de 14 individuos (10 mujeres y 4 hombres), edad 23 (± 4 anos), peso corporal 61 (± 7 kg) y estatura 168 cm (± 5 cm). Como material de coleta fueron utilizados frecuencimetro Polar MZ1 (Finlândia), esfigmomanometro Vasquez-Lubry (Alemanha) e un estetoscopio Littman (EUA). Fue utilizado el test t-Student apareado, para efecto de comparacion entre los valores encontrados en las variables fisiologicas. El analisis estatistico tuvo como criterio de significancia p < 0,05. Todas las variables presentaron un valor medio mas alto en el SRS en relacion al SRD. Fueron consideradas FC, PAS, PAD y DP pre y post-ejercicio. Se entiende que el valor absoluto de la PA medido por lo metodo auscultatorio tiende a ser inferior a aquel registrado dentro de la arteria, mas, en situaciones de tests en ejercicios con intensidades diferentes, la variacion porcentual de la PAS presenta la misma tendencia que el metodo invasivo. Concluimos entonces, que los ejercicios de SRS y SRD no presentaron diferencias significativas en ninguno de los parametros fisiologicos estudiados. Por ello, en el SRD se observaron respuestas un poco abajo de estos parametros. Siendo asi, crear una realizacion necesaria de otros estudios analizando diferentes posiciones corporales, para que a traves de comparaciones podamos establecer una conducta cuanto a prescripcion de estos ejercicios.

EFFECTS OF DIFFERENT REST INTERVALS BETWEEN ANTAGONIST PAIRED SETS ON REPETITION PERFORMANCE AND MUSCLE ACTIVATION

Abstract Maia, MF, Willardson, JM, Paz, GA, and Miranda, H. Effects of different rest intervals between antagonist paired sets on repetition performance and muscle activation. J Strength Cond Res 28(9): 2529–2535, 2014—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.

Influence of Load Intensity on Postexercise Hypotension and Heart Rate Variability after a Strength Training Session

Abstract Figueiredo, T, Willardson, JM, Miranda, H, Bentes, CM, Reis, VM, and Simão, R. Influence of load intensity on postexercise hypotension and heart rate variability after a strength training session. J Strength Cond Res 29(10): 2941–2948, 2015—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.

Influence of exercise order on muscle damage during moderate-intensity resistance exercise and recovery

This study aimed to investigate the role of exercise order on total number of repetitions and to evaluate the possible importance on muscle damage and on rating perceived exertion (RPE). Ten trained participants completed two sequences: sequence A (SEQA) was leg press (LP), leg extension (LE), leg curl (LC), bench press (BP), shoulder press (SP), and triceps extension (TE) and in sequence B (SEQB), the order of execution of the exercises was reversed. Highest creatine kinase (CK) concentrations were observed 24 hours following both sessions, but no differences were found at any time between them, revealing that muscle damage has occurred. There were significant differences between SEQA and SEQB in the total number of repetitions for TE, LE, and LC. Our results suggest that differences in total strength production when exercise order is changed must be explained by some other mechanisms besides muscle damage and RPE.

Influence of number of sets on blood pressure and heart rate variability after a strength training session.

Abstract Figueiredo, T, Rhea, MR, Peterson, M, Miranda, H, Bentes, CM, Machado de Ribeiro dos Reis, V, and Simão, R. Influence of number of sets on blood pressure and heart rate variability after a strength training session. J Strength Cond Res 29(6): 1556–1563, 2015—The purpose of this study was to compare the acute effects of 1, 3, and 5 sets of strength training (ST), on heart rate variability (HRV) and blood pressure. Eleven male volunteers (age: 26.1 ± 3.6 years; body mass: 74.1 ± 8.1 kg; height: 172 ± 4 cm) with at least 6 months previous experience in ST participated in the study. After determining the 1 repetition maximum (1RM) load 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), the participants performed 3 different exercise sequences in a random order and 72 hours apart. During the first sequence, subjects performed a single set of 8–10 repetitions, at 70% 1RM, and with 2-minute rest interval between exercises. Exercises were performed in the following order: BP, LPD, SP, BC, TE, LP, LE, and LC. During the second sequence, subjects performed the same exercise sequence, with the same intensity, 2-minute rest interval between sets and exercises, but with 3 consecutive sets of each exercise. During the third sequence, the same protocol was followed but with 5 sets of each exercise. Before and after the training sessions, blood pressure and HRV were measured. The statistical analysis demonstrated a greater duration of postexercise hypotension after the 5-set program vs. the 1 set or 3 sets (p ⩽ 0.05). However, the 5-set program promoted a substantial cardiac stress, as demonstrated by HRV (p ⩽ 0.05). These results indicate that 5 sets of 8–10 repetitions at 70% 1RM load may provide the ideal stimulus for a postexercise hypotensive response. Therefore, ST composed of upper- and lower-body exercises and performed with high volumes are capable of producing significant and extended postexercise hypotensive response. In conclusion, strength and conditioning professionals can prescribe 5 sets per exercises if the goal is to reduce blood pressure after training. In addition, these findings may have importance, specifically in the early phase of high blood pressure development, but more research is needed in hypertensive populations to validate this hypothesis.