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ABSTRACT: Corrêa Neto, VG, Silva, DdN, Palma, A, de Oliveira, F, Vingren, JL, Marchetti, PH, da Silva Novaes, J, and Monteiro, ER. Comparison between traditional and alternated resistance exercises on blood pressure, acute neuromuscular responses, and rating of perceived exertion in recreationally resistance-trained men. J Strength Cond Res 38(5): e211-e218, 2024-The purpose of this study was to compare the acute effects of traditional and alternated resistance exercises on acute neuromuscular responses (maximum repetition performance, fatigue index, and volume load), rating of perceived exertion (RPE), and blood pressure (BP) in resistance-trained men. Fifteen recreationally resistance-trained men (age: 26.40 ± 4.15 years; height: 173 ± 5 cm, and total body mass: 78.12 ± 13.06 kg) were recruited and performed all 3 experimental conditions in a randomized order: (a) control (CON), (b) traditional (TRT), and (c) alternated (ART). Both conditions (TRT and ART) consisted of 5 sets of bilateral bench press, articulated bench press, back squat, and Smith back squat exercises at 80% 1RM until concentric muscular failure. The total number of repetitions performed across sets in the bench press followed a similar pattern for TRT and ART, with significant reductions between sets 3, 4, and 5 compared with set 1 (p < 0.05). There was a significant difference for set 4 between conditions with a lower number of repetitions performed in the TRT. The volume load was significantly higher for ART when compared with TRT. TRT showed significant reductions in BP after 10-, 40-, and 60-minute postexercise and when compared with CON after 40- and 60-minute postexercise. However, the effect size illustrated large reductions in systolic BP during recovery in both methods. Thus, it is concluded that both methods reduced postexercise BP.

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The aim of the present study was to assess the effects of beta-alanine supplementation on muscle strength and thickness. Nineteen resistance-trained men (age: 27.3 ± 5.5 years; height: 178 ± 10 cm; body mass: 83.4 ± 9.7 kg; training experience: 5.9 ± 3.9 years) were allocated to one of the following groups: Beta-alanine (BA) (6.4 g/day of beta-alanine) or Placebo (PLA) (6.4 g/day of maltodextrin). Subjects completed 4 resistance training sessions per week for 8 weeks. The following assessments were performed before and after intervention periods: 1 repetition maximum (1RM) and 60%1RM tests in the bench press (60%1RMBENCH) and back squat (60%1RMSQUAT) exercises; muscle thickness assessment of biceps brachialis (MTBB), triceps brachialis (MTTB), and vastus lateralis (MTVL) by ultrasonography. No significant difference between groups was observed for the absolute increase (pre-post intervention) in the 1RMBENCH (mean difference = 0.8 kg; p = 0.679), 1RMSQUAT (mean difference = 0.1 kg; p = 0.992), MTBB (mean difference = 0.7 mm; p = 0.637), MTTB (mean difference = 1.4 mm; p = 0.282), MTVL (mean difference = 1.6 mm; p = 0.311), 60%1RMBENCH (mean difference = 0.5 repetitions; p = 0.670) and 60%1RMSQUAT (mean difference = 0.7 repetitions; p = 0.690). In conclusion, the 8-week training period induced significant strength and morphological responses. However, the addition of beta-alanine supplementation did not enhance these adaptive outcomes.

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The aim of the present study was to compare the myoelectric activation and peak force (PF) between pullover (PO) and pulldown (PW) exercises in different shoulder joint positions during maximal isometric contractions (0o, 45o, 90o, 135o, and 180°). Fifteen young, healthy, resistance-trained men were recruited. The participants performed three maximal voluntary isometric contractions for each exercise at five shoulder joint positions. The myoelectric activation (iEMG) from pectoralis major (PM); latissimus dorsi (LD); posterior deltoid (PD), and PF were measured. For PF, there were significant main effects for exercise and joint positions (p < 0.001). For iEMG PM, there was significant a main effect for joint positions (p < 0.001). There was a significant interaction between exercises and joint positions (p < 0.001). For iEMG LD, there was a significant main effect for joint positions (p < 0.001). There was no significant interaction between exercises and joint positions. For iEMG PD, there was a significant main effect for joint positions (p < 0.001). There was no significant interaction between exercises and joint positions. For RPE, there were no significant differences between exercises and joint positions. The study concludes that specific shoulder joint positions affect PF production and iEMG during both exercises. RPE was not affected.

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The present study investigated acute muscular performance and metabolic responses to resistance training (RT) with inter-set stretching (ISS). Seventeen resistance-trained men (age: 30.0 ± 5.6 years; body mass: 81.8 ± 13.4 kg; height: 173 ± 6.2 cm; RT experience: 4.6 ± 1.7 years) completed the ISS and traditional training (TT) protocol seven days apart in a randomized order. In both protocols, 7 sets of the seated cable fly exercise were performed with a 10-repetition maximum (10-RM) load. During the ISS protocol, subjects completed inter-set passive static stretching of the agonist muscles for 45 seconds, while a passive rest (no stretching) was adopted for the same duration in the TT protocol. The change in maximal bench press strength (1-RM), muscle swelling (ultrasound) of the pectoralis major (PMMS), and blood lactate were assessed immediately following each protocol. Additionally, the total load lifted (TLL) and internal training load (ITL) were assessed in both protocols. There was no difference between protocols for the change in maximal bench press 1-RM (p > 0.05). There were higher values for PMMS (p < 0.05) and blood lactate (p < 0.05) following the TT versus the ISS protocol. The TT resulted in higher TLL (p < 0.05) and ITL values (p < 0.05) versus the ISS protocol. Resistance training with inter-set stretching results in lower acute performance and metabolic responses versus traditional training with passive rest between sets. Therefore, inter-set stretching might be applied within a periodized program on lower intensity days to reduce the overall stress of a session.

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ABSTRACT: Monteiro, ER, Pescatello, LS, Winchester, JB, Corrêa Neto, VG, Brown, AF, Budde, H, Marchetti, PH, Silva, JG, Vianna, JM, and Novaes, JdS. Effects of manual therapies and resistance exercise on postexercise hypotension in women with normal blood pressure. J Strength Cond Res 36(4): 948-954, 2022-The purpose of this investigation was to examine the acute effects of resistance exercise (RE) and different manual therapies (static stretching and manual massage [MM]) performed separately or combined on blood pressure (BP) responses during recovery in women with normal BP. Sixteen recreationally strength-trained women (age: 25.1 ± 2.9 years; height: 158.9 ± 4.1 cm; body mass: 59.5 ± 4.9 kg; body mass index: 23.5 ± 1.9 kg·m-2; baseline systolic BP median: 128 mm Hg; and baseline diastolic BP median: 78 mm Hg) were recruited. All subjects performed 6 experiments in a randomized order: (a) rest control (CON), (b) RE only (RE), (c) static-stretching exercise only (SS), (d) MM only, (e) RE immediately followed by SS (RE + SS), and (f) RE immediately followed by MM (RE + MM). RE consisted of 3 sets of bilateral bench press, back squat, front pull-down, and leg press exercises at 80% of 10RM. Static stretching and MM were applied unilaterally in 2 sets of 120 seconds to each of the quadriceps, hamstring, and calf regions. Systolic (SBP) and diastolic BP were measured before (rest) and every 10 minutes for 60 minutes following (Post 10-60) each intervention. There were significant intragroup differences for RE in Post-50 (p = 0.038; d = -2.24; ∆ = -4.0 mm Hg). Similarly, SBP intragroup differences were found for the SS protocol in Post-50 (p = 0.021; d = -2.67; ∆ = -5.0 mm Hg) and Post-60 (p = 0.008; d = -2.88; ∆ = -5.0 mm Hg). Still, SBP intragroup differences were found for the MM protocol in Post-50 (p = 0.011; d = -2.61; ∆ = -4.0 mm Hg) and Post-60 (p = 0.011; d = -2.74; ∆ = -4.0 mm Hg). Finally, a single SBP intragroup difference was found for the RE + SS protocol in Post-60 (p = 0.024; d = -3.12; ∆ = -5.0 mm Hg). Practitioners should be aware that SS and MM have the potential to influence BP responses in addition to RE or by themselves and therefore should be taken into consideration for persons who are hypertensive or hypotensive.

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BACKGROUND: The present study investigated the mid-term effects of training muscle groups once- versus twice-daily on morphofunctional adaptations in trained men. METHODS: Participants were randomly assigned to 1 of 2 experimental groups: 1 daily session per muscle group (1S, N.=11), where every muscle group was trained once a day or 2 daily sessions per muscle group (2S, N.=12), where every muscle group was trained twice. Testing was conducted before intervention and after 8 weeks for maximal strength (1RM) and muscular endurance (60%1RM) for bench press and parallel back squat exercises, and muscle thickness (MT) of the biceps brachii, triceps brachii, vastus lateralis, anterior quadriceps and pectoralis major. RESULTS: The major findings were as follows: 1) the increase in 1RM back squat was significantly greater in 2S (∆=16.1%) compared to 1S (∆=7.8%) (P<0.05); 2) both groups significantly increased bench press 1RM (1S: ∆=4.6%; 2S: ∆=6.8%), back squat 60% 1RM (1S: ∆=19.0%; 2S: ∆=24.3%), bench press 60% 1RM (1S: ∆=15.4%; 2S: ∆=24.0%) and all MT outcomes (P<0.05 for all), with no differences between experimental groups (1S and 2S). CONCLUSIONS: This study provides evidence that a twice-daily resistance training augments lower-body muscular strength; however, the daily frequency does not seem to have any additive effect on upper-body muscular strength, muscular endurance, and muscle hypertrophy in trained men.

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Previous studies investigated the effects of foam rolling (FR) on measurements of strength and power. However, the acute effect of FR on muscle thickness (MT) and pressure pain threshold (PPT) after multiple sets of resistance exercise remains to be elucidated. The aim of the present study was to examine the effect of one and three minutes of quadriceps FR on muscle thickness (vastus lateralis [VL] and rectus femoris [RF]), pain threshold (VL and RF), and total load lifted (TLL) on multiple sets of knee extension. Nine resistance-trained men (age: 24.8 ± 5.2 years; height: 177 ± 7 cm; total body mass 77.7 ± 6.2 kg) participated the study. MT, PPT, and performance on multiple sets of knee extension were compared after performing passive recovery (CON), one minute (FR1), or three minutes of FR (FR3). A similar total training load among experimental conditions was observed. There was a greater increase on VL muscle thickness after FR3 when compared to CON and FR1. In addition, there was an increase on rectus femoris PPT two minutes post FR3, with no differences between conditions. These results indicate that longer duration FR-protocol may acutely increase muscle thickness of the vastus lateralis muscle without negatively affect the TLL and PTT.

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The aims of this study were to compare muscle activity of the anterior deltoid, medial deltoid, and posterior deltoid in the bench press, dumbbell fly, shoulder press, and lateral raise exercises. Thirteen men experienced in strength training volunteered for the study. Muscle activation was recorded during maximum isometric voluntary contraction (MVIC) for data normalization, and during one set of 12 repetitions with the load of 60% 1RM in all exercises proposed. One-way repeated-measures ANOVA with Bonferroni's posthoc was applied using a 5% significance level. For anterior deltoid, the shoulder press (33.3% MVIC) presented a significantly higher level of activation when compared to other exercises. Also, no significant difference was found between the bench press (21.4% MVIC), lateral raise (21.2% MVIC), and dumbbell fly (18.8% MVIC). For the medial deltoid, the lateral raise (30.3% MVIC) and shoulder press (27.9% MVIC) presented a significantly higher level of activity than the bench press (5% MVIC) and dumbbell fly (3.4% MVIC). Besides, no significant difference was found between the bench press and the dumbbell fly. For the posterior deltoid, the lateral raise (24% MVIC) presented a significantly higher level of activation when compared to other exercises. For the posterior deltoid portion, the shoulder press (11.4% MVIC) was significantly more active than the bench press (3.5% MVIC) and dumbbell fly (2.5% MVIC). Moreover, no significant difference was found between the bench press and the dumbbell fly. In conclusion, the shoulder press and lateral raise exercises showed a higher level of muscle activation in the anterior deltoid and medial deltoid when compared to the bench press and dumbbell fly exercises.

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The type of exercise is a relevant resistance training-variable that might be manipulated in order to induce significant increases in muscle strength. The aim of this study was to analyze the influence of multi-joint vs single-joint resistance exercises on maximal strength. Sixteen resistance-trained men (age: 23.1 ± 4.4 years; body mass: 86.0 ± 12.8; height: 177.9 ± 6.4 cm; training experience: 4.2 ± 3.4 years) performed one of the following training protocols for six weeks: MULTI, consisting of only multi-joint exercises or SINGLE, consisting of only single-joint exercises. Subjects were then submitted to a three-week washout period, before being submitted to the other protocol for another six weeks. A linear periodization model was adopted in which external load was increased and the repetition range was decreased every two weeks. Maximal dynamic strength of bench press (1RMBENCH) and squat exercises (1RMSQUAT), a percentage variation of total load lifted (ΔTLL) and internal training load (ITL) were measured. Similar increases in 1RMBENCH (MULTI: 10.8%, p < 0.001; SINGLE: 5.5%, p < 0.001) and 1RMSQUAT (MULTI: 19.7%, p < 0.001; SINGLE: 19.0%, p < 0.001) were observed after the MULTI and SINGLE protocols. A decrease in TLL was detected for both exercise protocols; however, the SINGLE protocol induced a greater decrease, compared to the MULTI protocol (-35 ± 11% vs -42 ± 5%, respectively; p = 0.026). A greater ITL for the MULTI was observed when compared to the SINGLE (12.1%; p < 0.001). In conclusion, resistance training protocols with different exercise modalities seem to produce similar strength increases in resistance-trained men.

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Zaroni, RS, Brigatto, FA, Schoenfeld, BJ, Braz, TV, Benvenutti, JC, Germano, MD, Marchetti, PH, Aoki, MS, and Lopes, CR. High resistance-training frequency enhances muscle thickness in resistance-trained men. J Strength Cond Res 33(7S): S140-S151, 2019-The purpose of this study was to compare the effect a split training routine with muscle groups trained once per week (SPLIT) vs. whole-body split training routine with muscle groups trained 5 days per week (TOTAL) on neuromuscular adaptations in well-trained men. Eighteen healthy men (height = 177.8 ± 6.6 cm; total body mass = 84.4 ± 8.1 kg; age = 26.4 ± 4.6 years) were recruited to participate in this study. The experimental groups were matched according to baseline strength and then randomly assigned to 1 of the 2 experimental groups: SPLIT (n = 9) or TOTAL (n = 9). Prestudy and poststudy testing included 1RM for bench press, parallel back-squat and machine close-grip seated row, as well as an ultrasound analysis of the muscle thickness (MT) of the elbow flexors, triceps brachii, and vastus lateralis. After 8 weeks of training, no significant difference between groups was noted for all 1RM tests (p > 0.05). TOTAL induced a significantly greater increase in MT of the forearm flexors and vastus lateralis (p < 0.05). In conclusion, muscle strength increment is similar regardless of the experimental conditions studied; however, TOTAL may confer a potentially superior hypertrophic effect.

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Brigatto, FA, Braz, TV, Zanini, TCdC, Germano, MD, Aoki, MS, Schoenfeld, BJ, Marchetti, PH, and Lopes, CR. Effect of resistance training frequency on neuromuscular performance and muscle morphology after 8 weeks in trained men. J Strength Cond Res 33(8): 2104-2116, 2019-The purpose of this study was to investigate the chronic effects of training muscle groups 1 day per week vs. 2 days per week on neuromuscular performance and morphological adaptations in trained men with the number of sets per muscle group equated between conditions. Participants were randomly assigned in 2 experimental groups: 1 session·wk per muscle group (G1, n = 10), where every muscle group was trained once a week with 16 sets or 2 sessions·wk per muscle group (G2, n = 10), where every muscle group was trained twice a week with 8 sets per session. All other variables were held constant over the 8-week study period. No significant difference between conditions for maximal strength in the back squat or bench press, muscle thickness in the elbow extensors, elbow flexors, or quadriceps femoris, and muscle endurance in the back squat and bench press performed at 60% 1 repetition maximum was detected. Effect size favored G2 for some outcome measurements, suggesting the potential of a slight benefit to the higher training frequency. In conclusion, both G1 and G2 significantly enhance neuromuscular adaptations, with a similar change noted between experimental conditions.

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BACKGROUND: Kinesiology Tape (KT) is widely used in sports rehabilitation and by those performing physical activity, however, there is no consensus in the scientific literature about its effectiveness on performance, strength or muscle activation.Purpose: The purpose of this study was to measure the acute effects of KT in static rest, and during knee extension maximal voluntary isometric contraction (MVIC) performance in resistance trained men.Study Design: Observational, descriptive, comparative. METHODS: Eighteen young, healthy, trained males (age: 25 ± 6 years, height: 176.0 ± 5 cm, and mass: 81.8 ± 8.0 kg) volunteered to participate. Initially, they were in a relaxed sitting position of 90 degrees knee flexion with their limb supported by the machine lever arm to measure passive tension of the tissues of the knee joint. Then, they performed three MVIC trials of five seconds each with a three-minute rest between trials, in four randomized experimental conditions, with 10-min rest between conditions: (a) control, no taping; (b) Knee Sleeve; (c) KT; and (d) sham. During all MVICs, peak force, impulse, and muscle activation of the vastus lateralis (integrated electromyography [IEMG] and median frequency) were measured. RESULTS: Repeated measures ANOVAs revealed no statistical differences between conditions for passive tension (p > 0.05), peak force (p > 0.05), impulse (p > 0.05), IEMG (p > 0.05), or median frequency (p > 0.05). CONCLUSION: KT does not influence passive tension during static position at 90 degrees of knee flexion. KT does not affect quadriceps activation or force production during a maximal voluntary isometric contraction in the same position. LEVEL OF EVIDENCE: 3a.

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Changes in range of motion affect the magnitude of the load during the squat exercise and, consequently, may influence muscle activation. The purpose of this study was to evaluate muscle activation between the partial and full back squat exercise with external load equated on a relative basis between conditions. Fifteen young, healthy, resistance-trained men (age: 26 ± 5 years, height: 173 ± 6 cm) performed a back squat at their 10 repetition maximum (10RM) using 2 different ranges of motion (partial and full) in a randomized, counterbalanced fashion. Surface electromyography was used to measure muscle activation of the vastus lateralis, vastus medialis, rectus femoris, biceps femoris (BF), semitendinosus, erector spinae, soleus (SL), and gluteus maximus (GM). In general, muscle activity was highest during the partial back squat for GM (p = 0.004), BF (p = 0.009), and SL (p = 0.031) when compared with full-back squat. There was no significant difference for rating of perceived exertion between partial and full back squat exercise at 10RM (8 ± 1 and 9 ± 1, respectively). In conclusion, the range of motion in the back squat alters muscle activation of the prime mover (GM) and stabilizers (SL and BF) when performed with the load equated on a relative basis. Thus, the partial back squat maximizes the level of muscle activation of the GM and associated stabilizer muscles.

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Aim: the aim was to investigate the influence of a maximal isometric muscle action of the elbow extensors on the contralateral dynamic task of the elbow flexors. Methods Seventeen recreationally trained men (23.3 ± 4.9 yrs, BMI: 24.8 ± 2.2 Kg/m²) underwent two randomized different testing sessions separated by one week. In the control session (CON) all subjects performed a maximum number of repetitions test (RMs) at 75%1RM using the right elbow flexors. The experimental session (EXP) was similar to the CON; however, all subjects were instructed to perform RMs at 75%1RM by using the right elbow flexors and maintaining the maximal voluntary contraction of the left elbow extensors during the test. RMs, rating of perceived exertion (RPE), and training volume (TV) were measured and compared between sessions. Results: The EXP showed a significant 10.4% increase on the RMs (13.8 vs. 12.5, p < lt; 0.001, d = 0.44) and 12.1% increase in TV (238.0 vs. 212.4 kg, p >lt; 0.001, d = 0.43) than CON. No differences were observed for RPE between sessions. Conclusion: The maximum voluntary contraction of the left elbow extensors increased the RMs of the contralateral elbow flexors, reflecting a higher TV, and no differences in the RPE. Our results suggest that the investigated method may be a viable and practical alternative to increase the acute strength performance of elbow flexors when using submaximal loads.(AU)

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BACKGROUND: Despite the well-known declines in driving performance with advancing age, there is little understanding of the specific factors that predict changes in key determinants such as braking time. OBJECTIVES: The aims of this study were to determine the extent to which age, muscle strength, cognition and postural balance are associated with braking performance in middle-aged and older adults. METHODS: Male and female middle-aged adults (n=62, age=39.3±7.1years) and older adults (n=102, age=70.4±5.8years) were evaluated for braking performance, as well as in several motor and cognitive performance tasks. The motor evaluation included isokinetic ankle plantar flexor muscle strength, handgrip strength, and postural balance with and without a cognitive task. The cognitive assessment included the Mini Mental State Examination. Braking performance was measured using a driving simulator. RESULTS: Older adults exhibited 17% slower braking time, lower strength, and poorer performance in the postural balance (p<0.001). For both older and middle-aged adults, significant correlates of braking time included performance in the postural balance tests, muscle strength, and cognitive function. However, after full model adjustment, only postural balance and cognitive function were significantly associated. CONCLUSION: Muscle strength, postural balance, and cognition are associated with braking time, and may affect the safety of and driving performance in older adults. These findings may help to inform specific targeted interventions that could preserve driving performance during aging.

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The purposes of this study were to measure the acute effects of knee wraps (KWs) on knee and hip joint kinematics, dynamic muscle activation from the vastus lateralis (VL) and gluteus maximus (GM), and rating of perceived exertion (RPE) during the back squat exercise at 2 different intensities. Fourteen resistance-trained men (age: 24 ± 4 years, height: 176 ± 6 cm, body mass: 81 ± 11 kg, back squat 1 repetition maximum [1RM]: 107 ± 30 kg, 3 ± 1 year of back squat experience) performed 1 set of 3 repetitions under 4 different conditions, to a depth of approximately 90 degrees of knee joint flexion, and in random order: KWs at 60% 1RM (KW60), KWs at 90% 1RM (KW90), without knee wraps (NWs) at 60% 1RM (NW60), and NWs at 90% 1RM (NW90). The dependent variables obtained were vertical and horizontal bar displacement, peak joint angle in the sagittal plane (hip and knee joints), concentric and eccentric muscle activation (by integrated electromyography) from the VL and GM, and RPE. For muscle activity, there were significant decreases in the VL NWs at 60% 1RM (p = 0.013) and a significant increase NWs at 90% 1RM (p = 0.037). There was a significant increase in VL muscle activity at 90% 1RM, when compared with 60% 1RM (KW: p = 0.001, effect size (ES) = 1.51 and NW: p < 00.001, ES = 1.67). There was a decrease in GM muscle activity NWs only at 60% 1RM (p = 0.014). There was a significant increase in GM muscle activity at 90% 1RM, when compared with 60% 1RM (KW: p < 0.001 and NW: p < 0.001). For peak hip joint flexion angle, there was significant decreases between intensities (90% 1RM < 60% 1RM) only to NWs condition (p = 0.009), and there was greater knee flexion NWs for both intensities: 60% 1RM (p < 0.001) and 90% 1RM (p = 0.018). For normalized vertical barbell displacement, there were significant differences between intensities when using KWs (p = 0.022). There were significant differences in RPE between 60 and 90% 1RM for each condition: KWs (p < 0.001) and NWs (p < 0.001). In conclusion, the use of KWs results in decreased muscle activation of the VL at the same intensity (90% 1RM).

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The purpose of the present study was to evaluate the acute effects of an upper limb static-stretching (SS) protocol on the maximal concentric jump performance. We recruited 25 young healthy, male, resistance trained individuals (stretched group, n = 15 and control group, n = 10) in this study. The randomized between group experimental protocol consisted of a three trials of maximal concentric jump task, before and after a SS of the upper limb. Vertical ground reaction forces (vGRF) and surface electromyography (sEMG) of both gastrocnemius lateralis (GL) and vastus lateralis (VL) were acquired. An extensive SS was employed consisting of ten stretches of 30 seconds, with 15 seconds of rest, and 70-90% of the point of discomfort (POD). ANOVA (2x2) (group x condition) was used for shoulder joint range of motion (ROM), vGRF and sEMG. A significant interaction for passive ROM of the shoulder joint revealed significant increases between pre- and post-SS protocol (p < 0.001). A significant interaction demonstrated decreased peak force and an increased peak propulsion duration between pre- and post-stretching only for stretch group (p = 0.021, and p = 0.024, respectively. There was a significant main effect between groups (stretch and control) for peak force for control group (p = 0.045). Regarding sEMG variables, there were no significant differences between groups (control versus stretched) or condition (pre-stretching versus post-stretching) for the peak amplitude of RMS and IEMG for both muscles (VL and GL). In conclusion, an acute extensive SS can increase the shoulder ROM, and negatively affect both the propulsion duration and peak force of the maximal concentric jump, without providing significant changes in muscle activation. Key pointsThe jump performance can be affected negatively by an intense extensive static-stretching protocol.An intense acute extensive SS protocol can affect positively the shoulder ROM.The intense acute extensive SS protocol does not change the level of muscle activation for vastus lateralis and gastrocnemius lateralis.

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The aim of this study was to investigate the acute effects of unilateral ankle plantar flexors static- stretching on surface electromyography (sEMG) and the center of pressure (COP) during a single-leg balance task in both lower limbs. Fourteen young healthy, non-athletic individuals performed unipodal quiet standing for 30s before and after (stretched limb: immediately post-stretch, 10 and 20 minutes and non-stretched limb: immediately post-stretch) a unilateral ankle plantar flexor static- stretching protocol [6 sets of 45s/15s, 70-90% point of discomfort (POD)]. Postural sway was described using the COP area, COP speed (antero-posterior and medio-lateral directions) and COP frequency (antero-posterior and medio-lateral directions). Surface EMG (EMG integral [IEMG] and Median frequency[FM]) was used to describe the muscular activity of gastrocnemius lateralis. Ankle dorsiflexion passive range of motion increased in the stretched limb before and after the static-stretching protocol (mean ± SD: 15.0° ± 6.0 and 21.5° ± 7.0 [p < 0.001]). COP area and IEMG increased in the stretch limb between pre-stretching and immediately post-stretching (p = 0.015 and p = 0.036, respectively). In conclusion, our static- stretching protocol effectively increased passive ankle ROM. The increased ROM appears to increase postural sway and muscle activity; however these finding were only a temporary or transient effect. Key PointsThe postural control can be affected by static- stretching protocol.The lateral gastrocnemius muscle action was increased after the static- stretching protocol.The static- stretching effects remain for less than 10 minutes.

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The purpose of this study was to compare the number of maximum repetitions (RMs) performed at 80% of one-repetition maximum (1RM) and 80% of one-repetition maximum eccentric (1RMecc) test for the preacher-curl (PC) and the bench-press (BP) exercises. Fifteen resistance-trained men participated in this counterbalanced-crossover study. There was no significant difference in the number of RMs performed at 80%-1RM (PC: 7.0±1.2 RMs and BP: 5.8±1.3 RMs) and 80%-1RMecc (PC: 6.0±1.1 RMs and BP: 5.4±1.1 RMs) for both exercises. No significant difference in the numbers of RMs was detected between the PC (80%-1RM: 7.0±1.2 RMs and 80%-1RMecc: 6.0±1.1 RMs) and BP exercises (80%-1RM: 5.8±1.3 RMs and 80%-1RMecc: 5.4±1.1 RMs) for both intensities. In conclusion, the number of RMs performed by resistance-trained men was not affected by the maximum load intensity based on muscle action and the exercise selection...

O objetivo deste estudo foi comparar o número de repetições máximas (RMs) realizadas com intensidade de 80% dos testes de uma repetição máxima (1RM) e 80% de uma repetição máxima excêntrica (1RMecc) para os exercícios supino-horizontal (SH) e rosca-scott (RS). Quinze homens com experiência em treinamento de força participaram desse estudo randomizado cruzado. Não houve diferença significativa no número de RMs realizadas a 80%-1RM (RS: 7,0±1,2 RMs e SH: 5,8±1,2 RMs) e 80%-1RMecc (RS: 6,0±1,1 RMs e SH: 5,4±1,1 RMs) para ambos os exercícios. Não foi detectada diferença significativa no número de RMs entre o exercício RS (80%-1RM: 7,0±1,2 RMs and 80%-1RMecc: 6,0±1,1 RMs) e SH (80%-1RM: 5,8 ±1,2 RMs and 80%-1RMecc: 5,4±1,1 RMs) para ambas intensidades. Em conclusão, o número de RMs realizados por homens treinados em força não foi afetado pela intensidade máxima da carga baseada na ação muscular e pela seleção de exercícios...

El objetivo de este estudio fue comparar el número de repeticiones máximas (RMS) realizado con una intensidad de 80% de una repetición máxima (1RM) y el 80% de una repetición máxima excéntrica (1RMecc) para el ejercicio supino horizontal (SH) y rosca scott (RS). Quince hombres con experiencia en el entrenamiento de fuerza participaron en este estudio cruzado aleatorio. No hubo diferencia significativa en el número de los RMs realizado a 80% 1RM (RS: 7,0±1,2 RMs e SH: 5,8±1,2 RMs) y 80%-1RMecc (RS: 6,0±1,1 RMs e SH: 5,4±1,1 RMs) para ambos ejercicios. No se detectó diferencia significativa en el número de los RMs entre el ejercicio RS (80%- 1RM: 7,0±1,2 RMs and 80%-1RMecc: 6,0±1,1 RMs) y SH (80%-1RM: 5,8 ±1,2 RMs and 80%-1RMecc: 5,4±1,1 RMs) para ambas intensidades. En conclusión, el número de RMs realizados por hombres entrenados en la fuerza no afectó la intensidad máxima de la carga basada en la acción muscular y la selección de los ejercicios...

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RESUMO

It is unclear whether athletes change their postural control over the course of a full sport season, or become more asymmetrical with respect to their neuromuscular performance over the same period. The aim of this study was to investigate the effects of a full sport season on the postural control of team handball elite athletes. Ten healthy, elite male team handball players performed bipodal standing (BP) and right and left unipodal standing (UP) during 30s. We used the RMS and speed of the center of pressure to describe postural sway. For the BP task, the sway was lower at the end of the season (p<0.005). For the UP tasks, the sway was lower at the end of the season only for the non-dominant limb (p<0.001). Differences between limbs were observed only at the end of the season (p<0.03). In conclusion, a full team handball season did not lead to deterioration of the athletes' postural control, but by the end of the season, the athletes were more asymmetrical.

Não é claro na literatura científica se atletas mudam seu controle postural ao longo de uma temporada esportiva, ou mesmo se tornam mais assimétricos em relação ao seu desempenho neuromuscular durante o mesmo período. O objetivo deste estudo foi investigar os efeitos de uma temporada esportiva completa no controle postural de atletas de elite do handebol. Dez jogadores de elite de handebol, saudáveis, realizaram a tarefa de postura ereta quieta bipodal (BP) e unipodal direito e esquerdo durante 30 segundos. Foi utilizada a RMS e a velocidade do centro de pressão para descrever a oscilação postural. Para a tarefa de BP, a oscilação foi menor após a temporada esportiva (p < 0,005). Para as tarefas unipodais, a oscilação foi menor após temporada esportiva apenas para o membro não dominante (p < 0,001). Apenas após a temporada, foram observadas diferenças entre os membros (p < 0,03). Em conclusão, uma temporada esportiva para o handebol não levou à deterioração do controle postural dos atletas, entretanto no final da temporada, os atletas apresentaram-se mais assimétricos.

No está claro en la literatura científica si los atletas cambian su control postural a lo largo de una temporada deportiva o incluso si llegan a ser más asimétricas en relación con su rendimiento neuromuscular durante el mismo período. El objetivo de este estudio fue investigar los efectos de una temporada deportiva completa en control postural de deportistas de elite de balonmano. Diez jugadores de balonmano de élite, sanos, llevaron a cabo la tarea de la tranquilidad de la postura de pie bipodal (BP) y unipodal izquierda y derecha durante 30 segundos. RMS fue utilizado y la velocidad del centro de presión para describir el balanceo postural. Para la tarea de BP, la oscilación fue menor después de la temporada de deportes (p < 0,005). Para unipodais las tareas, la oscilación fue menor después de la temporada deportiva para el miembro no dominante (p < 0,001). Solamente después de la temporada, se observaron diferencias entre los miembros (p < 0,03). En conclusión, una temporada de deportes para el balonmano no conduce al deterioro del control postural de los atletas, sin embargo al final de la temporada, los atletas presentaron más asimétrica.

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