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 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.

Knee Frontal Plane Projection Angle: A Comparison Study Between Drop Vertical Jump and Step-Down Tests With Young Volleyball Athletes.

STUDY DESIGN: Observational study. CONTEXT: Altered frontal plane knee mechanics during dynamic tasks have been often associated with lower-extremity injuries. Strategies to decrease these risk factors and improve knee joint stability are often applied in rehabilitation and training environments. OBJECTIVE: The purpose of this study was to compare knee joint frontal plane projection angles (FPPA) via 2-dimensional video analysis during drop vertical jump (DVJ) and step-down test (SDT) tasks in the preferred and nonpreferred limbs of young male and female volleyball players. METHODS: A total of 60 young male (n = 29) and female (n = 31) volleyball players (13.6 [1.1] y, 62.2 [11.2] kg, and 170.8 [10] cm) participated in this study. Once the athletes were screened for inclusion and exclusion criteria, limb preference was operationally defined as the preferred kicking leg or the foot used for stair climbing. In a randomized study design, participants were asked to perform a bilateral DVJ and unilateral step-down landing tasks for both preferred and nonpreferred limb. Kinematic analysis was performed via a 2-dimensional video recording of knee joint FPPA alignment. RESULTS: No difference was noted in FFPA during DVJ and SDT tasks between preferred and nonpreferred limbs in both male and female groups (P > .05). The FFPA was significantly higher for both limbs during DVJ versus SDT in both groups (P ≤ .05), but it was not different between male and female athletes. CONCLUSIONS: Based on these findings, clinicians may expect young male and female volleyball athletes to demonstrate similar and symmetrical lower-extremity 2-dimensional knee joint FPPA values across screening tests intended to identify lower-extremity injury risk factors. However, greater FPPA values should be expected during the more dynamic DVJ task.

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.

Volume Load and Neuromuscular Fatigue During an Acute Bout of Agonist-Antagonist Paired-Set vs. Traditional-Set Training.

The purpose of this study was to investigate the acute effects of performing paired-set (PS) vs. traditional-set (TS) training over 3 consecutive sets, on volume load and electromyographic fatigue parameters of the latissimus dorsi, biceps brachii, pectoralis major, and triceps brachii muscles. Fifteen trained men performed 2 testing protocols (TS and PS) using 10 repetition maximum loads. The TS protocol consisted of 3 sets of bench press (BP) followed by 3 sets of wide-grip seated row (SR). The PS consisted of 3 sets of BP and 3 sets of SR performed in an alternating manner. Volume load was calculated as load × repetitions. The electromyographic signal, time (CRMS) and frequency (Cf5) domain, parameters were recorded during SR. Under the PS protocol, sets of SR were performed immediately after the sets of BP. A 2-minute rest interval between the completion of the set of SR and the subsequent set of BP was implemented (e.g., between PSs). Under the TS protocol, 2-minute rest intervals were implemented between all sets. BP and SR volume loads decreased significantly from set 1 to set 2 and from set 2 to set 3 under both conditions. Volume load was greater for all sets of both exercises under PS as compared with TS. Muscle fatigue indices were greater under PS as compared with TS. In general, these results indicate that as compared with TS, PS produced a greater training volume in less time and may induce greater fatigue and thereby provide an enhanced training stimulus.

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.

Electromyography Activation of the Lower-Limb Muscles Adopting a Physioball and Elastic Band to Stabilize the Knee Joint During Multiple Sets With Submaximal Loads.

STUDY DESIGN: Crossover design. CONTEXT: Excessive valgus and varus force which affected the knee joint during dynamic tasks has been often associated to lower extremity injuries. Strategies to increase the resistance against these asymmetries (eg, the use of a physioball between the knees or elastic bands around the knees) are often applied in rehabilitation and conditioning programs. OBJECTIVE: The purpose of this study was to investigate the effect of performing leg press (LP) 45° using a physioball and elastic band over multiple sets with submaximal loads on electromyographic (EMG) amplitude and fatigue indices. METHODS: 18 trained females volunteered (age: 24.4 ± 2.1 y; height: 168.1 ± 4 cm; body mass: 65.1 ± 4.4 kg) participated in this study. The 10 repetition maximum (RM) loads were determined for the LP. Then, 3 experimental protocols were followed in a randomized crossover design over 3 nonconsecutive days: control protocol-the participants performed 4 LP sets; physioball between knees-4 LP sets were performed with the physioball between the knees; elastic band-4 LP sets were performed with the elastic band involving the knees. Ten repetitions were performed during each set with 70% of 10-RM loads; EMG spectral indices (CRMS and Cf5) was collected from the biceps femoris (BF), vastus lateralis (VL), vastus medialis obliquus (VMO), and rectus femoris (RF) muscles. RESULTS: Higher levels of CRMS and Cf5 were noted for RF, VL, and VM muscles using the physioball and elastic band when compared with control protocol, respectively. CRMS index of BF muscle was significantly higher using physioball and elastic band protocol versus control condition, respectively. CONCLUSION: Therefore, both physioball and elastic band can be adopted during LP with the goal to reduce excessive varus and valgus forces, respectively, even performing consecutive sets with submaximal loads. Furthermore, this may be an interesting alternative to increasing quadriceps activation and improving the knee joint stabilization.

Oxidative stress and antioxidant biomarker responses after a moderate-intensity soccer training session.

The present study investigated the effects of a moderate-intensity soccer training session on the production of reactive oxygen species (ROS) and the antioxidant capacity in athletes along with the biomarkers creatine kinase and transaminases for lesions in muscle and liver cells. Twenty-two male soccer players participated in this study. Blood samples were collected 5 min before and after a moderate-intensity game simulation. The results showed a decrease in the concentration of reduced glutathione (GSH) from an elevation in the production of ROS that maintained the redox homeostasis. Although the session promoted an elevated energy demand, observed by an increase in lactate and glucose levels, damage to muscle and/or liver cells was only suggested by a significant elevation in the levels of alanine transaminase (ALT). Of the two biomarkers analysed, the results suggest that measurements of the ALT levels could be adopted as a method to monitor recovery in athletes.

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.

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.

The Effect of Rest Interval Length on Repetition Consistency and Perceived Exertion During Near Maximal Loaded Bench Press Sets.

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 ≤ 0.05); no significant differences were noted between the 2, 3, and 5 minutes rest conditions. For the 1-minute rest condition, performance reductions (relative to the first set) were observed commencing with the second set; whereas for the other conditions (2, 3, and 5 minutes rest), performance reductions were not evident until the third and fourth sets. The RPE values before each of the successive sets were significantly greater, commencing with the second set for the 1-minute vs. the 3 and 5 minutes rest conditions. Significant increases were also evident in RPE immediately after each set between the 1 and 5 minutes rest conditions from the second through fifth sets. These findings indicate that when utilizing an absolute 3RM load for the bench press, practitioners may prescribe a time-efficient minimum of 2 minutes rest between sets without significant impairments in repetition performance. However, lower perceived exertion levels may necessitate prescription of a minimum of 3 minutes rest between sets.

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

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.

Maximal repetition performance, rating of perceived exertion, and muscle fatigue during paired set training performed with different rest intervals.

BACKGROUND/OBJECTIVE: The purpose of this study was to examine rest interval length between agonist-antagonist paired set training (PS) on maximal repetition performance, rating of perceived exertion, and neuromuscular fatigue. METHODS: Fourteen trained men (age, 24.2 ± 1.1 years; height, 175 ± 5.5 cm; body mass, 76.6 ± 7.0 kg) performed two experimental protocols in random order with 2 minutes (P2) or 4 minutes (P4) between agonist-antagonist PS, which consisted of a bench press set followed immediately by a seated row set with 8-repetition maximum loads, respectively. A total of three PS were performed for each rest interval protocol. The total repetitions performed and the rating of perceived exertion were recorded for each exercise set within each rest interval protocol. Electromyography signals were recorded for the posterior deltoid, biceps brachii, pectoralis major, and triceps brachii muscles during the SR exercise. The electromyography signals were then used to calculate a fatigue index for each rest interval protocol. RESULTS: No significant differences were identified in the total repetitions completed between rest interval protocols for the bench press (P2 = 22.9 ± 1.3 and P4 = 22.6 ± 0.8) and seated row (P2 = 25.4 ± 1.7 and P4 = 25.1 ± 1.3). However, a significantly higher fatigue index was found for all muscles under the P2 versus the P4 protocol. CONCLUSION: When performing agonist-antagonist PS, prescribing a shorter rest interval between PS may induce higher levels of fatigue, albeit with similar total repetitions versus a longer rest interval.

Acute effects of antagonist static stretching in the inter-set rest period on repetition performance and muscle activation.

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