Effects of Medicine Wall Ball Throws With Whole-Body Vibration on Bat Swing Performance in Collegiate Baseball Players.

ABSTRACT: Buso, D, Willardson, JM, and Shafer, AB. Research note: Effects of medicine wall ball throws with whole-body vibration on bat swing performance in collegiate baseball players. J Strength Cond Res 37(10): 2071-2075, 2023-The purpose of this study was to examine the effect of medicine ball wall throws performed with whole-body vibration on bat swing performance in 13 highly trained collegiate baseball players. The experimental session involved the athletes' usual warm-up followed by baseline bat swings. The baseline bat swings were followed by 3 sets of 5 medicine ball wall throws while standing on a whole-body vibration platform set at 40 Hz and with 30 seconds rest between sets. Subjects then rested passively for 5 minutes before taking post-test bat swings. Performance was evaluated with bat speed (m·second-1), time to contact (secs), rotational acceleration (G's), and exit velocity (m·second-1). Paired t tests were used to compare baseline and post-test values (p ≤ 0.05). Effect size (d) statistics were also calculated to determine the magnitude of treatment effects. It was found that bat speed (p = 0.02; d = 0.22) and exit velocity (p = 0.03; d = 0.48) were significantly faster versus baseline, whereas rotational acceleration (p = 0.10; d = 0.23) and time to contact (p = 0.44; d = -0.12) were not significantly different from baseline, respectively. These results suggest that the addition of medicine ball wall throws with whole-body vibration can significantly increase key parameters of bat swing performance. Practitioners and coaches may consider including these combined exercise stimuli as part of workouts or during games for potentially greater success at the plate.

The Effect of Different Rest Intervals Between Agonist-Antagonist Paired Sets on Training Performance and Efficiency.

ABSTRACT: 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.

Effects of Differing Foam Rolling Periods on Training Volume and Myoelectric Responses of Lower-Body Muscles.

ABSTRACT: 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.

Acute and Long-Term Comparison of Fixed vs. Self-Selected Rest Interval Between Sets on Upper-Body Strength.

ABSTRACT: 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.

Acute Hormone Responses Subsequent to Agonist-Antagonist Paired Set vs. Traditional Straight Set Resistance Training.

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.

Myoelectric Responses of Lower-Body Muscles Performing Squat and Lunge Exercise Variations Adopting Visual Feedback With a Laser Sensor.

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).

Effect of Different Circuit Training on Cardiovascular Responses in Cirrhotic Patients.

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.

Postexercise Hypotension and Heart Rate Variability Responses Subsequent to Traditional, Paired Set, and Superset Resistance Training Methods.

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.

Strength and Muscular Adaptations After 6 Weeks of Rest-Pause vs. Traditional Multiple-Sets Resistance Training in Trained Subjects.

Prestes, J, Tibana, RA, de Araujo Sousa, E, da Cunha Nascimento, D, de Oliveira Rocha, P, Camarço, 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.

Prior Band-Resisted Squat Jumps Improves Running and Neuromuscular Performance in Middle-Distance Runners.

Post-activation potentiation (PAP) conditioning has been reported to increase performance. Most research has examined PAP effects on strength/power activities, whereas the effects on endurance sports are understudied. The aim of this study was to characterize PAP conditioning stimulus effects on a subsequent 5x1 km running trial. A randomized, within subjects, repeated measures study utilized 12 male, endurance-trained athletes, who performed a full warm-up, conditioning exercise intervention (4x5 repetition maximum band-resisted squat jumps) or a control condition prior to a 5x1 km time trial run. Tests were conducted immediately prior to the intervention, after each kilometer, immediately following the 5x1 km run, and at seven and ten minutes post 5 km run. Measures included the interpolated twitch technique (ITT), evoked contractile properties, maximum voluntary isometric contractions (MVIC) plantar flexor force, drop jump, rating of perceived exertion, and heart rate. The PAP stimulus reduced the time to complete the run (3.6%; p = 0.07, d = 0.51), and decreased the time to complete kilometer one (8%; d = 1.08, p = 0.014). Jump height (p = 0.02; 9.2%) and reactive strength index (p = 0.035; 16%) increased with PAP. F100 (force produced in the first 100ms of the MVIC) and MVIC force with PAP increased at kilometers 3 (p = 0.04, d=0.84), 4 (p = 0.034, d = 0.29), and 7min post-run (p = 0.03, d = 0.60). Voluntary activation (ITT) increased at 7min post-run (p = 0.04, d = 0.59) with PAP, yet decreased at 7min post-run in the control condition (p = 0.03, d = 0.36). A prior band-resisted squat protocol decreased running time and improved neuromuscular properties in endurance athletes running 5x1 km.

Mixed Session Periodization as a New Approach for Strength, Power, Functional Performance, and Body Composition Enhancement in Aging Adults.

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 (p < 0.01), seated leg curl (p < 0.01), and 12RM cable chest press (p < 0.001). For CMJ performance, the MSP and TP groups significantly increased at week 7 (p < 0.001). The MSP and TP groups significantly improved functional task performance, including TUG (p < 0.001), upstairs (p < 0.01), and downstairs (p < 0.01) after training. Furthermore, body composition for the lower limbs significantly changed for the MSP and TP groups, with increased fat-free mass (p < 0.001) and decreased fat mass (p < 0.01) 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.

Repetition Performance and Blood Lactate Responses Adopting Different Recovery Periods Between Training Sessions in Trained Men.

Miranda, H, Maia, MF, Paz, GA, de Souza, JAAA, Simão, 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.

Myoeletric Activity of the Quadriceps During Leg Press Exercise Performed With Differing Techniques.

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.

Maximal Strength Performance and Muscle Activation for the Bench Press and Triceps Extension Exercises Adopting Dumbbell, Barbell, and Machine Modalities Over Multiple Sets.

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.

Ischemic Preconditioning and Placebo Intervention Improves Resistance Exercise Performance.

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.

Long Rest Interval Promotes Durable Testosterone Responses in High-Intensity Bench Press.

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.

Effect of Different Interset Rest Intervals on Performance of Single and Multijoint Exercises With Near-Maximal Loads.

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.

Influence of Rest Interval Length Between Sets on Blood Pressure and Heart Rate Variability After a Strength Training Session Performed By Prehypertensive Men.

Figueiredo, T, Willardson, JM, Miranda, H, Bentes, CM, Machado Reis, V, Freitas de Salles, B, and Simão, 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.

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

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 Blood Flow Restriction During Low-Intensity Resistance Exercise on the Postexercise Hypotensive Response.

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 ≤ 0.05) in SBP occurred at 30 minutes (125.86 ± 9.33 mm Hg) and 40 minutes (125.53 ± 10.19 mm Hg) after exercise when compared with baseline (132.86 ± 9.12 mm Hg) and significant decreases in DBP and MBP occurred at 20 minutes, 30 minutes, and 40 minutes after exercise vs. baseline (p ≤ 0.05). Therefore, we conclude that exercises engaging a relatively small amount of muscle mass, such as the BC (or other similar single joint exercises), might be performed at a lower intensity with BFR to promote a postexercise hypotensive response.