Inter-Repetition Rest Impact on the Estimated Repetitions in Reserve at Various Loads and Proximities to Neuromuscular Failure.

ABSTRACT: Ruiz-Alias, SA, Ramirez-Campillo, R, Leando Quidel-Catrilelbún, ME, García-Pinillos, F, and Pérez-Castilla, A. Inter-repetition rest Impact on the estimated repetitions in reserve at various loads and proximities to neuromuscular failure . J Strength Cond Res XX(X): 000-000, 2024-The repetitions in reserve (RIR) estimation method allows for monitoring resistance training set volume. However, a significant bias is commonly observed when ending the set further from neuromuscular failure and using lower relative loads. Is unclear if implementing an IRR could improve its estimation validity. This study aimed to determine if the RIR estimation is influenced by the IRR at different relative loads and proximities to neuromuscular failure during the back squat (BQ) and bench press (BP) exercises. After a familiarization session, 19 male subjects (age, 21-26 years) completed an experimental session for each IRR configuration: IRR0 (without rest), IRR3 (3 seconds of rest), and SSIRR (self-selected rest [up to 5 seconds]). In each session, single sets to neuromuscular failure were performed at 3 relative loads (65% 1 repetition maximum [1RM], 75% 1RM, 85% 1RM) for BQ and BP exercises. Using the Estimated Repetitions to Failure scale, subjects estimated the RIR associated with a score of "5" and "2" (i.e., RIR-5 and RIR-2). The results revealed no interactions between the RIR estimation and IRR for BQ (RIR-5: p = 0.812; RIR-2: p = 0.084) or BP (RIR-5: p = 0.884; RIR-2: p = 0.944). Subjects provided valid estimations, with overestimation (BQ RIR-5: 0%; BQ RIR-2: 2.9%; BP RIR-5: 1.1%; BP RIR-2: 2.3%) or underestimation (BQ RIR-5: 14.9%; BQ RIR-2: 4%; BP RIR-5: 15.2% BP RIR-2: 8.2%) in few sets. In conclusion, the RIR estimation method seems valid, and the IRR (0-5 seconds) does not influence its validity at 65-85% 1RM loads nor proximities to neuromuscular failure (RIR-2, RIR-5).

The Effect of Strength Training Methods on Middle-Distance and Long-Distance Runners' Athletic Performance: A Systematic Review with Meta-analysis.

BACKGROUND: The running performance of middle-distance and long-distance runners is determined by factors such as maximal oxygen uptake (VO2max), velocity at VO2max (vVO2max), maximum metabolic steady state (MMSS), running economy, and sprint capacity. Strength training is a proven strategy for improving running performance in endurance runners. However, the effects of different strength training methods on the determinants of running performance are unclear. OBJECTIVE: The aim of this systematic review with meta-analysis was to compare the effect of different strength training methods (e.g., high load, submaximal load, plyometric, combined) on performance (i.e., time trial and time until exhaustion) and its determinants (i.e., VO2max, vVO2max, MMSS, sprint capacity) in middle-distance and long-distance runners. METHODS: A systematic search was conducted across electronic databases (Web of Science, PubMed, SPORTDiscus, SCOPUS). The search included articles indexed up to November 2022, using various keywords combined with Boolean operators. The eligibility criteria were: (1) middle- and long-distance runners, without restriction on sex or training/competitive level; (2) application of a strength training method for ≥ 3 weeks, including high load training (≥ 80% of one repetition maximum), submaximal load training (40-79% of one repetition maximum), plyometric training, and combined training (i.e., two or more methods); (3) endurance running training control group under no strength training or under strength training with low loads (< 40% of one repetition maximum); (4) running performance, VO2max, vVO2max, MMSS and/or sprint capacity measured before and after a strength training intervention program; (5) randomized and non-randomized controlled studies. The certainty of evidence was assessed using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach. A random-effects meta-analysis and moderator analysis were performed using Comprehensive meta-analysis (version 3.3.0.70). RESULTS: The certainty of the evidence was very low to moderate. The studies included 324 moderately trained, 272 well trained, and 298 highly trained athletes. The strength training programs were between 6 and 40 weeks duration, with one to four intervention sessions per week. High load and combined training methods induced moderate (effect size = - 0.469, p = 0.029) and large effect (effect size = - 1.035, p = 0.036) on running performance, respectively. While plyometric training was not found to have a significant effect (effect size = - 0.210, p = 0.064). None of the training methods improved VO2max, vVO2max, MMSS, or sprint capacity (all p > 0.072). Moderators related to subject (i.e., sex, age, body mass, height, VO2max, performance level, and strength training experience) and intervention (i.e., weeks, sessions per week and total sessions) characteristics had no effect on running performance variables or its determinants (all p > 0.166). CONCLUSIONS: Strength training with high loads can improve performance (i.e., time trial, time to exhaustion) in middle-distance and long-distance runners. A greater improvement may be obtained when two or more strength training methods (i.e., high load training, submaximal load training and/or plyometric training) are combined, although with trivial effects on VO2max, vVO2max, MMSS, or sprint capacity.

What We Do Not Know About Stretching in Healthy Athletes: A Scoping Review with Evidence Gap Map from 300 Trials.

BACKGROUND: Stretching has garnered significant attention in sports sciences, resulting in numerous studies. However, there is no comprehensive overview on investigation of stretching in healthy athletes. OBJECTIVES: To perform a systematic scoping review with an evidence gap map of stretching studies in healthy athletes, identify current gaps in the literature, and provide stakeholders with priorities for future research. METHODS: Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 and PRISMA-ScR guidelines were followed. We included studies comprising healthy athletes exposed to acute and/or chronic stretching interventions. Six databases were searched (CINAHL, EMBASE, PubMed, Scopus, SPORTDiscus, and Web of Science) until 1 January 2023. The relevant data were narratively synthesized; quantitative data summaries were provided for key data items. An evidence gap map was developed to offer an overview of the existing research and relevant gaps. RESULTS: Of ~ 220,000 screened records, we included 300 trials involving 7080 athletes [mostly males (~ 65% versus ~ 20% female, and ~ 15% unreported) under 36 years of age; tiers 2 and 3 of the Participant Classification Framework] across 43 sports. Sports requiring extreme range of motion (e.g., gymnastics) were underrepresented. Most trials assessed the acute effects of stretching, with chronic effects being scrutinized in less than 20% of trials. Chronic interventions averaged 7.4 ± 5.1 weeks and never exceeded 6 months. Most trials (~ 85%) implemented stretching within the warm-up, with other application timings (e.g., post-exercise) being under-researched. Most trials examined static active stretching (62.3%), followed by dynamic stretching (38.3%) and proprioceptive neuromuscular facilitation (PNF) stretching (12.0%), with scarce research on alternative methods (e.g., ballistic stretching). Comparators were mostly limited to passive controls, with ~ 25% of trials including active controls (e.g., strength training). The lower limbs were primarily targeted by interventions (~ 75%). Reporting of dose was heterogeneous in style (e.g., 10 repetitions versus 10 s for dynamic stretching) and completeness of information (i.e., with disparities in the comprehensiveness of the provided information). Most trials (~ 90%) reported performance-related outcomes (mainly strength/power and range of motion); sport-specific outcomes were collected in less than 15% of trials. Biomechanical, physiological, and neural/psychological outcomes were assessed sparsely and heterogeneously; only five trials investigated injury-related outcomes. CONCLUSIONS: There is room for improvement, with many areas of research on stretching being underexplored and others currently too heterogeneous for reliable comparisons between studies. There is limited representation of elite-level athletes (~ 5% tier 4 and no tier 5) and underpowered sample sizes (≤ 20 participants). Research was biased toward adult male athletes of sports not requiring extreme ranges of motion, and mostly assessed the acute effects of static active stretching and dynamic stretching during the warm-up. Dose-response relationships remain largely underexplored. Outcomes were mostly limited to general performance testing. Injury prevention and other effects of stretching remain poorly investigated. These relevant research gaps should be prioritized by funding policies. REGISTRATION: OSF project ( https://osf.io/6auyj/ ) and registration ( https://osf.io/gu8ya ).

Evaluating the Effects of Consecutive Phases of Plyometric Jump Training on Athletic Performance in Male Soccer Players: The Effect of Training Frequency and Volume Manipulations.

ABSTRACT: Moran, J, Vali, N, Tallent, J, Howe, L, Clemente, FM, Chaabene, H, and Ramirez-Campillo, R. Evaluating the effects of consecutive phases of plyometric jump training on athletic performance in male soccer players: The effect of training frequency and volume manipulations. J Strength Cond Res XX(X): 000-000, 2024-This 14-week, 2-phase study aimed to determine the relative effects of 1 day or 2 days of volume-matched plyometric training on athletic performance (10- and 40-m sprints, change of direction [COD], and vertical jump [VJ]) in male soccer players (phase 1). The objective of phase 2 was to determine the relative effects of higher- and lower-volume plyometric training protocols in maintaining any previously attained increases in athletic performance from phase 1. A randomized parallel-group trial design was utilized. In phase 1, subjects (n = 24; mean age: 19.5 ± 1.2 years; mean height: 179.7 ± 7.1 cm; mean weight: 69.8 ± 6.9 kg) were randomly allocated to 1 of 2 groups to receive either 1 day or 2 days of volume- and intensity-matched plyometric training for a 7-week period. For the second 7-week period (phase 2), half of each group was randomized into either a lower-volume or higher-volume plyometric training group. In phase 1, both the 1-day group and the 2-day group attained comparably significant (p < 0.001) increases in performance in all fitness tests ranging from effect sizes (ESs) (d) of 0.4 (95% confidence interval: 0.11 to 0.70) for 10-m sprint to 1.51 (0.42-2.60) for VJ. There were no significant differences between the performance increases in the 2 groups. In phase 2, neither group increased or decreased performance, maintaining all previously attained increases with only trivial ESs observed (-0.02 [-0.58 to 0.53] to 0.11 [-0.38 to 0.61]). Increases in 10- and 40-m sprint speed, COD speed, and VJ height can be achieved and maintained with as little as 1 plyometric training session per week. Sessions can include 120 jumps to induce increases of the reported magnitudes, with 60 jumps to maintain these increases thereafter, in male soccer players.

Effects of plyometric jump training on measures of physical fitness and lower-limb asymmetries in prepubertal male soccer players: a randomized controlled trial.

BACKGROUND: High level of physical fitness is a paramount soccer performance factor. As such, developing key components of physical fitness such as sprinting, jumping, and change of direction (CoD) at an early age empowers both short- and long-term performance success. Although previous research in prepubertal male soccer players has reported physical fitness performance enhancements following plyometric jump training (PJT), the effects on inter-limb asymmetries remain unclear. OBJECTIVE: To assess the effects of PJT on measures of physical fitness and inter-limb asymmetries in prepubertal male soccer players. METHODS: A total of 27 participants were recruited, and randomly assigned to either a PJT group (n = 13; age = 12.7 ± 0.2 years; maturity offset = -1.6 ± 0.7) or an active control group (CG) (n = 14; age = 11.8 ± 0.4 years; maturity offset = -2.51 ± 0.61). The training intervention lasted eight-week and was conducted during the in-season period, with twice-weekly sessions. Physical fitness tests were conducted before and after the intervention, including the 505 change-of-direction (CoD; [505 CoD test]), countermovement-jump (CMJ) height, standing-long-jump (SLJ) distance, and single-leg hop test for distance with dominant (SHTD-D) and non-dominant legs (SHTD-ND). A jump-based asymmetry score was calculated as the difference between HTD and HTND. RESULTS: ANCOVA analysis revealed significant between-group differences in all physical fitness measures at post-test. Specifically, the PJT group showed significant large improvements in CMJ height, SLJ distance, HTD and HTND, and CoD speed (d = 0.84 to 2.00; ∆1.05% to 16.85%). Moreover, the PJT group showed a significant, small reduction in the inter-limb asymmetry score (d = 0.43; ∆-45.21%). In contrast, no significant changes were reported in the CG between pre-and post-tests (d = 0.07 to 0.24; ∆0.21% to 0.98%). CONCLUSIONS: The incorporation of PJT into the training schedules of prepubertal male soccer players resulted in positive effects on various measures of physical fitness. Furthermore, our findings suggest that PJT can reduce lower-limb asymmetry, which could potentially decrease the risk of lower limb injuries. TRIAL REGISTRATION: This study does not report results related to healthcare interventions using human participants and therefore it was not prospectively registered.

Optimization of Postural Control, Balance, and Mobility in Children with Cerebral Palsy: A Randomized Comparative Analysis of Independent and Integrated Effects of Pilates and Plyometrics.

The paradigm of comprehensive treatment approaches for children with cerebral palsy has gained traction, prompting clinicians to deliberate between independent and integrated treatment delivery. However, this decision-making process is often hindered by the dearth of empirical evidence available to inform optimal therapeutic strategies. This study, therefore, sought to compare the effects of Pilates-based core strengthening (PsCS), plyometric-based muscle loading (PlyoML), and their combination on postural control, balance, and mobility in children with unilateral cerebral palsy (ULCP). Eighty-one children with ULCP (age: 12-18 years) were randomized to PsCS (n = 27), PlyoML (n = 27), or a combined intervention (n = 27; equated for total sets/repetitions) group. The three interventions were applied twice/week over 12 successive weeks. Postural control (directional and overall limits of stability-LoS), balance, and mobility (Community Balance and Mobility Scale-CB&M; Functional Walking Test-FWT; Timed Up and Down Stair test-TUDS) were assessed pre- and post-intervention. The combined group exhibited greater increases in directional LoS compared to PsCS and PlyoML including the backward (p = 0.006 and 0.033, respectively), forward (p = 0.015 and 0.036, respectively), paretic (p = 0.017 and 0.018, respectively), and non-paretic directions (p = 0.006 and 0.004, respectively)], and this was also the case for overall LoS (p < 0.001 versus PsCS and PlyoML). In addition, the combined group displayed greater improvements compared to the PsCS and PlyoML groups regarding CB&M (p = 0.037 and p = 0.002, respectively), FWT (p = 0.012 and p = 0.038, respectively), and TUDS (p = 0.046 and p = 0.021, respectively). In conclusion, the combined PsCS and PlyoML exercise program promotes considerably greater improvements in postural control, balance, and mobility compared to unimodal training in children with ULCP.

Effects of Sand Surface Plyometric and Sprint Training on Physical and Technical Skill Performance in Beach Handball Players.

This study compared the effects of a 6-week combined plyometric and sprint-training program on the sand to regular preseason training, on the athletic performance and technical actions of beach handball (BH) players. Athletes were randomly assigned either to the control (CG, n = 12; BH training only) or the experimental group (EG, n = 12; plyometric + sprint + BH training). Assessments conducted before and after the training period included a squat jump, a countermovement jump, the Abalakov jump, a 15-m sprint, a modified Course-Navette endurance test, and four sport-specific BH throwing speed tests: a standing penalty throw, a 3-step running throw, a jump throw, and a 360º jump throw. The training intervention enhanced all athletic performance measures (all, p < 0.05). In contrast, the only improvement in the CG included endurance performance (p< 0.05). Significant time-group differences were noted in favor of the EG compared to the CG (p< 0.05) in the squat jump, the countermovement jump, the Abalakov jump, the jump throw velocity and 360º jump throw velocity. In conclusion, compared to BH regular training, 6 weeks of sand surface preseason plyometric and sprint training combined with regular BH training induced greater improvements in athletic performance and specific skills in BH players.

Effects of physical exercise on executive functions of individuals with schizophrenia spectrum disorders: Protocol for a systematic review and meta-analysis.

INTRODUCTION: Executive functions are commonly impaired in individuals with schizophrenia spectrum disorders. Physical exercise has the potential for improving executive functions and can be easily implemented as a therapeutic method. However, there are only few systematic reviews of exercise effects in schizophrenia including cognitive outcomes, and no meta-analytical syntheses of effects on "cool" and "hot" executive functions. The purpose of this systematic review and meta-analysis will be to determine the effects of physical exercise on "cool" and "hot" executive functions of adults with schizophrenia spectrum disorders. METHODS AND ANALYSIS: This protocol was guided by PRISMA-P guidelines. Studies will be searched using combinations of keywords and medical terms in the Web of Science, PubMed, Scopus, and EBSCO databases. Inclusion criteria will be determined as per PICOS approach. The risk of bias will be assessed using the Cochrane RoB2 tool. The certainty of evidence (per outcome) will be assessed using the GRADE method. The meta-analyses will be performed using the DerSimonian and Laird random effects model. Effect sizes (Hedges' g) with 95% confidence intervals will be calculated for each main outcome. CONCLUSIONS: The results of this review may be useful for mental health professionals to design treatment plans for adults with schizophrenia spectrum disorders, offering potential benefits related to the quality of life and cognitive abilities of this population. PROSPERO REGISTRATION NUMBER: CRD42023392295.

Effect of Strength Training Programs in Middle- and Long-Distance Runners' Economy at Different Running Speeds: A Systematic Review with Meta-analysis.

BACKGROUND: Running economy is defined as the energy demand at submaximal running speed, a key determinant of overall running performance. Strength training can improve running economy, although the magnitude of its effect may depend on factors such as the strength training method and the speed at which running economy is assessed. AIM: To compare the effect of different strength training methods (e.g., high loads, plyometric, combined methods) on the running economy in middle- and long-distance runners, over different running speeds, through a systematic review with meta-analysis. METHODS: A systematic search was conducted across several electronic databases including Web of Science, PubMed, SPORTDiscus, and SCOPUS. Using different keywords and Boolean operators for the search, all articles indexed up to November 2022 were considered for inclusion. In addition, the PICOS criteria were applied: Population: middle- and long-distance runners, without restriction on sex or training/competitive level; Intervention: application of a strength training method for ≥ 3 weeks (i.e., high loads (≥ 80% of one repetition maximum); submaximal loads [40-79% of one repetition maximum); plyometric; isometric; combined methods (i.e., two or more methods); Comparator: control group that performed endurance running training but did not receive strength training or received it with low loads (< 40% of one repetition maximum); Outcome: running economy, measured before and after a strength training intervention programme; Study design: randomized and non-randomized controlled studies. Certainty of evidence was assessed with the GRADE approach. A three-level random-effects meta-analysis and moderator analysis were performed using R software (version 4.2.1). RESULTS: The certainty of the evidence was found to be moderate for high load training, submaximal load training, plyometric training and isometric training methods and low for combined methods. The studies included 195 moderately trained, 272 well trained, and 185 highly trained athletes. The strength training programmes were between 6 and 24 weeks' duration, with one to four sessions executed per week. The high load and combined methods induced small (ES = - 0.266, p = 0.039) and moderate (ES = - 0.426, p = 0.018) improvements in running economy at speeds from 8.64 to 17.85 km/h and 10.00 to 14.45 km/h, respectively. Plyometric training improved running economy at speeds ≤ 12.00 km/h (small effect, ES = - 0.307, p = 0.028, ß1 = 0.470, p = 0.017). Compared to control groups, no improvement in running economy (assessed speed: 10.00 to 15.28 and 9.75 to 16.00 km/h, respectively) was noted after either submaximal or isometric strength training (all, p > 0.131). The moderator analyses showed that running speed (ß1 = - 0.117, p = 0.027) and VO2max (ß1 = - 0.040, p = 0.020) modulated the effect of high load strength training on running economy (i.e., greater improvements at higher speeds and higher VO2max). CONCLUSIONS: Compared to a control condition, strength training with high loads, plyometric training, and a combination of strength training methods may improve running economy in middle- and long-distance runners. Other methods such as submaximal load training and isometric strength training seem less effective to improve running economy in this population. Of note, the data derived from this systematic review suggest that although both high load training and plyometric training may improve running economy, plyometric training might be effective at lower speeds (i.e., ≤ 12.00 km/h) and high load strength training might be particularly effective in improving running economy (i) in athletes with a high VO2max, and (ii) at high running speeds. PROTOCOL REGISTRATION: The original protocol was registered ( https://osf.io/gyeku ) at the Open Science Framework.

Endurance Performance Adaptations between SSG and HIIT in Soccer Players: A Meta-analysis.

The objective of this systematic review with meta-analysis was to compare the endurance performance chronic adaptations induced by running-based high-intensity interval training (HIIT), small-sided games (SSGs), and combined HIIT+SSGs in male and female youth and adult soccer players. The studies included in this review followed the PICOS criteria: (i) healthy soccer players; (ii) interventions based on SSGs; (iii) comparators exposed to only HIIT or combined SSGs+HIIT; (iv) endurance performance variables. Studies were searched for in the following databases: (i) PubMed; (ii) Scopus; (iii) SPORTDiscus; (iv) Web of Science. After conducting an initial database search that retrieved a total of 5,389 records, a thorough screening process resulted in the inclusion of 20 articles that met the eligibility criteria. Sixteen studies reported outcomes related to endurance performance measured through field-based tests, while five studies provided results from direct measurements of maximal oxygen uptake (VO2max). Results showed a non-significant small-magnitude favoring effect for the HIIT groups compared to the SSG groups (ES=0.37, p=0.074) for endurance, while a non-significant small-magnitude favoring SSGs was observed (ES=-0.20, p=0.303) for VO2max. Despite the very low certainty of evidence, the findings suggest similar effects induced by both SSG and HIIT on improving endurance performance and VO2max.

Water-Based Exercise in Patients With Nonspecific Chronic Low-Back Pain: A Systematic Review With Meta-Analysis.

ABSTRACT: Babiloni-Lopez, C, Fritz, N, Ramirez-Campillo, R, and Colado, JC. Water-based exercise in patients with nonspecific chronic low-back pain: a systematic review with meta-analysis. J Strength Cond Res 38(1): 206-219, 2024-This study aimed to systematically review and synthesize evidence (i.e., active [land-based training] and nonactive controls [e.g., receiving usual care]) regarding the effects of water-based training on patients with nonspecific chronic low-back pain (NSCLBP). Web of Science (WOS), PubMed (MEDLINE), EMBASE, EBSCO (SPORTDiscus; CINAHL), and PEDro were searched, with no date restrictions, until October 2021. The included studies satisfied the following criteria: (a) NSCLBP (≥12 weeks) patients, (b) water-based intervention, (c) control group (land-based trained; nonactive group), and (d) outcomes related to pain, disability, quality of life, or flexibility. The main outcome analyzed in the meta-analysis was pain intensity. Secondary outcomes included disability, body mass index, and flexibility. The random-effects model was used, and effect size (ES) values are presented with 95% confidence intervals (CIs). The impact of heterogeneity was assessed (I2 statistic), with values of <25%, 25-75%, and >75% representing low, moderate, and high levels, respectively. Alpha was set at p < 0.05. In conclusion, 15 studies (n = 524) were meta-analyzed. After intervention, pain intensity was reduced compared with nonactive controls (ES = -3.61; p < 0.001) and a similar reduction was noted when compared with land-based trained group (ES = -0.14; p = 0.359). Greater decrease in disability (ES = 2.15; p < 0.001) and greater increase in sit-and-reach (i.e., flexibility; ES = -2.44; p < 0.001) were noted after intervention compared with the nonactive group. In conclusion, water-based exercise therapy reduces pain intensity, disability, and increases flexibility in NSCLBP compared with nonactive subjects and was equally effective compared with land-based exercise to reduce pain. Favorable effects may be expected at ≤8 weeks. However, due to several methodological issues (e.g., high heterogeneity), for the improvement of most outcomes, we are unable to provide other than a weak recommendation in favor of intervention compared with control treatment.

Acute Effect of Different Velocity-Based Training Protocols on 2000-meter Rowing Ergometer Performance.

ABSTRACT: Leandro Quidel-Catrilelbún, ME, Ruiz-Alias, SA, García-Pinillos, F, Ramirez-Campillo, R, and Pérez-Castilla, A. Acute effect of different velocity-based training protocols on 2000-m rowing ergometer performance. J Strength Cond Res 38(1): e8-e15, 2024-This study aimed to explore the acute effect of 4 velocity-based resistance training (VBT) protocols on 2000-m rowing ergometer (RE2000) time trial, as well as the behavior of the maximal neuromuscular capacities when RE2000 is performed alone or preceded by VBT protocols in the same session. Fifteen male competitive rowers (15-22 years) undertook 5 randomized protocols in separate occasions: (a) RE2000 alone (control condition); (b) VBT against 60% of 1 repetition maximum (1RM) with a velocity loss in the set of 10% followed by RE2000 (VBT60-10 + RE2000); (c) VBT against 60% 1RM with a velocity loss in the set of 30% followed by RE2000 (VBT60-30 + RE2000); (d) VBT against 80% 1RM with a velocity loss in the set of 10% followed by RE2000 (VBT80-10 + RE2000); (e) VBT against 80% 1RM with a velocity loss in the set of 30% followed by RE2000 (VBT80-30 + RE2000). The load-velocity relationship (load-axis intercept [L0], velocity-axis intercept [v0], and area under the load-velocity relationship line [Aline]) was used to evaluate the maximal neuromuscular capacities during the prone bench pull exercise before and after each protocol. The time trial was significantly longer for VBT60-30 + RE2000 and VBT80-30 + RE2000 than for RE2000, VBT60-10 + RE2000 and VBT80-10 + RE2000 (all p < 0.001; ES = 0.10-0.15). L0 and Aline were significantly reduced after all protocols (p < 0.001; ES = 0.10-0.13), with Aline reduction more accentuated for VBT60-10 + RE2000, VBT60-30 + RE2000, VBT80-30 + RE2000, and RE2000 (all p = 0.001; ES = 0.11-0.18) than for VBT80-10 + RE2000 (p = 0.065; ES = 0.05). Therefore, VBT protocols with greater velocity loss in the set (30% vs. 10%) negatively affected subsequent rowing ergometer performance, in line with impairment in Aline pulling performance.

Effects of different plyometric training frequencies on physical performance in youth male volleyball players: a randomized trial.

This study aimed to analyze the effect of plyometric training (PT) at different frequencies on jump performance, running sprint speed, and service speed in youth male volleyball players. The participants were randomly assigned to one PT session per week (Experimental Group 1, EG1, n = 15), two PT sessions per week (Experimental Group 2, EG2, n = 14), and a control group (CG, n = 13). The total weekly jumping ranged between 98 and 196 jumps (equalized between, EG1 and, EG2). The assessments performed were squat jump (SJ), countermovement jump (CMJ), CMJ-arms, drop jump (DJ), 5-m sprint, 10-m sprint, and service speed. The intragroup comparisons showed that, EG1 significantly (p < 0.001) improved SJ (Δ = 12.74%; d = 1.30), CMJ (Δ = 11.94%; d = 1.71), CMJ-arms (Δ = 12.02%; d = 1.47), DJ (Δ = 10.93%; d = 1.30), 5-m sprint (Δ = -4.61%; d = 0.29), 10-m sprint (Δ = -3.95%; d = 0.40) and service speed (Δ = 8.17%; d = 1.53). Similarly, EG2 significantly (p˂ 0.001) improved SJ (Δ = 11.52%; d = 1.25), CMJ (Δ = 11.29%; d = 1.38), CMJ-arms (Δ = 11.42%; d = 1.26), DJ (Δ = 13.90%; d = 2.17), 5-m sprint (Δ = -3.85%; d = 0.25), 10-m sprint (Δ = -2.73%; d = 0.25) and service speed (Δ = 6.77%; d = 1.44). The CG significantly (p < 0.05) improved SJ (Δ = 2.68; d = 0.28), CMJ-arms (Δ = 2.30; d = 0.35), 5-m sprint (Δ = -1.27; d = 0.10) and service speed (Δ = 1.42; d = 0.30). Intergroup comparisons revealed significantly greater improvements in all variables (p < 0.001) in, EG1 and, EG2 concerning to CG. However, no significant differences were found between, EG1 and, EG2. A moderate weekly PT volume, distributed in one or two sessions per week, seems equally effective.

Internal workload in elite female football players during the whole in-season: starters vs non-starters.

The aim of this study was to quantify weekly internal workload across the in-season and compare the workload variables between starter and non-starter Spanish female first league (Liga Iberdrola) football players. Twenty-six participants belonging to the same team (age, height, and mass: 25.4 ± 6.1 years, 167.4 ± 4.8 cm and 57.96 ± 6.28 kg, respectively) participated in this study. Training loads (TL) and match loads (ML) were assessed through breath-cardiovascular (RPEbreath), leg-musculature (RPEleg) and cognitive (RPEcog) rating of perceived exertion (RPE0-10) for each training session and match during the in-season phase (35 weeks). Session-RPE (sRPE) was calculated by multiplying each RPE value by session duration (minutes). From these, total weekly TL (weekly TL+ML), weekly TL, weekly ML, chronic workload, acute:chronic workload ratio, training monotony, and training strain were calculated. Linear mixed models were used to assess differences for each dependent variable, with playing time (starter vs non-starter players) used as a fixed factor, and athlete, week, and team as random factors. The results showed that total weekly TL (d = 1.23-2.04), weekly ML (d = 4.65-5.31), training monotony (d = 0.48-1.66) and training strain (d = 0.24-1.82) for RPEbreath, RPEleg and RPEcog were higher for starters in comparison with non-starters (p = 0.01). Coaches involved in elite female football should consider implementing differential sRPE monitoring strategies to optimize the weekly load distribution for starters and non-starters and to introduce compensatory strategies to equalise players' total weekly load.

The Effects of Strength, Plyometric and Combined Training on Strength, Power and Speed Characteristics in High-Level, Highly Trained Male Youth Soccer Players: A Systematic Review and Meta-Analysis.

BACKGROUND: Male youth soccer players competing at a high level will typically engage in large volumes of soccer training from a young age. However, it is not known whether the high levels of habitual training that these high-performing players are exposed to limit their ability to respond to strength, plyometric or combined training interventions. OBJECTIVE: The primary aim of our systematic review and meta-analysis was to compare the specific effects of strength, plyometric and combined training with active controls (standard soccer training) on the strength, power and speed characteristics of high-level, highly trained young male soccer players. METHODS: We performed a literature search across PubMed, Scopus, CINAHL, Web of Science and SPORTDiscus to identify controlled studies that implemented strength, plyometric or combined training in high-level male youth soccer players. Participants were defined as high level or highly trained based on established guidelines related to either competition level or age-related weekly hours spent in soccer training. Studies needed to report at least one outcome of lower body strength, squat jump, countermovement jump, horizontal power, acceleration (0-10 m), speed (15-40 m) or change of direction speed. A meta-analysis was then performed using a random-effects model to determine the magnitude (Hedge's g) of training responses and whether effects differed across modes of training. RESULTS: From an initial return of 5464 papers, n = 34 studies met the inclusion criteria and provided a total sample of n = 1396 high-level male youth soccer players. Strength, plyometric and combined training resulted in improvements in strength, squat and countermovement jump, horizontal power, acceleration, change of direction speed (all p < 0.05; g = 0.73-1.08, moderate) and speed (p < 0.05; g = 0.40-0.59, small). Lower body strength was the only outcome where training mode had a significant effect (p < 0.05), with plyometric training producing small effects (g = 0.27, p < 0.05) compared with moderate effects for strength (g = 1.07, p < 0.05) and combined (g = 0.75, p < 0.05) training. Prediction intervals for overall effects (all training modes combined) showed that the greatest confidence that future training will lead to positive effects was in the squat and countermovement jump, horizontal power and acceleration (prediction intervals = 0.03-1.81). CONCLUSIONS: High-level, highly trained male youth soccer players can experience positive gains in indices of strength, power and speed from strength, plyometric and combined training, and the magnitude of gains are mostly similar across modes of training. Based on prediction intervals, there is a good level of certainty that future strength, plyometric and combined training in this population would lead to positive improvements in vertical and horizontal power and sprint acceleration.

Self-Massage Techniques for the Management of Pain and Mobility With Application to Resistance Training: A Brief Review.

ABSTRACT: MacLennan, M, Ramirez-Campillo, R, and Byrne, PJ. Self-massage techniques for the management of pain and mobility with application to resistance training: a brief review. J Strength Cond Res 37(11): 2314-2323, 2023-Fascial restrictions that occur in response to myofascial trigger points (MTrP), exercise-induced muscle damage (EIMD), and delayed onset of muscle soreness (DOMS) cause soft tissue to lose extensibility, which contributes to abnormal muscle mechanics, reduced muscle length, and decrements in joint range of motion (ROM) and actively contributes to musculoskeletal pain. Resistance training and in particular, weightlifting movements have unique mobility requirements imperative for movement efficacy and safety with ROM restrictions resulting in ineffective volume and intensity tolerance and dampened force output and power, which may lead to a failed lift or injury. Self-massage (SM) provides an expedient method to promote movement efficiency and reduce injury risk by improving ROM, muscular function, and reducing pain and allows athletes to continue to train at their desired frequency with minimal disruption from MTrPs-associated adverse effects. Thus, the aim of this review was to determine the efficacy of various self-massage tools in managing pain and mobility and to explore the potential benefits of SM on resistance training performance. Many SM devices are available for athletes to manage ROM restrictions and pain, including differing densities of foam rollers, roller massagers, tennis balls, and vibrating devices. To attenuate adverse training effects, a 10-to-20-minute bout consisting of 2-minute bouts of SM on the affected area may be beneficial. When selecting a SM device, athletes should note that foam rollers appear to be more effective than roller massagers, with vibrating foam rollers eliciting an increased reduction to pain perception, and tennis balls and soft massage balls were shown to be efficacious in targeting smaller affected areas.

The effects of backward vs. forward running training on measures of physical fitness in young female handball players.

Introduction: This study examined the effects of an 8-week backward running (BR) vs. forward running (FR) training programmes on measures of physical fitness in young female handball players. Methods: Twenty-nine players participated in this study. Participants were randomly assigned to a FR training group, BR training group, and a control group. Results and discussion: Within-group analysis indicated significant, small-to-large improvements in all performance tests (effect size [g] = 0.36 to 1.80), except 5-m forward sprint-time in the BR group and 5- and 10-m forward sprint-time in the FR group. However, the CG significantly decreased forward sprint performance over 10-m and 20-m (g = 0.28 to 0.50) with no changes in the other fitness parameters. No significant differences in the amount of change scores between the BR and FR groups were noted. Both training interventions have led to similar improvements in measures of muscle power, change of direction (CoD) speed, sprint speed either forward or backward, and repeated sprint ability (RSA) in young female handball players, though BR training may have a small advantage over FR training for 10-m forward sprint time and CoD speed, while FR training may provide small improvements over BR training for RSAbest. Practitioners are advised to consider either FR or BR training to improve various measures of physical fitness in young female handball players.

Effects of different cluster-set rest intervals during plyometric-jump training on measures of physical fitness: A randomized trial.

The optimal intra-set rest for cluster sets (CLS) during plyometric-jump training (PJT) to improve physical fitness remains unclear. The objective of this quasi-experimental study was to compare the effects of PJT with traditional (TRS) vs. CLS structures, using different intra-set rests, on the physical fitness of healthy participants. Forty-seven recreationally active young men performed 3-5 sets of 10-12 repetitions of upper- and lower-body PJT exercises twice a week for six weeks using different set configurations: TRS group (no intra-set rest), and the CLS10, CLS20 and CLS30 groups with 10, 20 and 30 s of intra-set rest, respectively, while the total rest period was equated. Pretest-posttest measurements were carried out 48 h before and after the intervention and the rating of fatigue (ROF) was also assessed using a numerical scale (0-10 points) 20 min after the first and last (i.e., 12th) session. There was no significant difference in the mean energy intake between groups (p > 0.05). The repeated measures ANOVA revealed that all groups showed similar improvements (p < 0.05) in body mass, body mass index, fat-free mass, one repetition maximum (dynamic strength) and repetitions to failure (muscular endurance) in back squat and chest press, handgrip strength, standing long jump, 20 m sprint, 9-m shuttle run (change of direction speed), and ROF. Of note, the ROF was lower for the CLS20 and CLS30 groups, independent from the training effect. The physical fitness of recreationally active young men improved after 6 weeks of PJT involving intra-set rest intervals of 0 s, 10 s, 20 s, or 30 s. However, an intra-set rest of 20 s and 30 s seems to induce lower exercise-induced fatigue perception.

Effects of Upper-Body Plyometric Training on Physical Fitness in Healthy Youth and Young Adult Participants: A Systematic Review with Meta-Analysis.

BACKGROUND: Upper-body plyometric training (UBPT) is a commonly used training method, yet its effects on physical fitness are inconsistent and there is a lack of comprehensive reviews on the topic. OBJECTIVE: To examine the effects of UBPT on physical fitness in healthy youth and young adult participants compared to active, specific-active, and passive controls. METHODS: This systematic review followed PRISMA 2020 guidelines and utilized the PICOS framework. PubMed, WOS, and SCOPUS were searched. Studies were assessed for eligibility using the PICOS framework. The effects of UBPT on upper-body physical fitness were assessed, including maximal strength, medicine ball throw performance, sport-specific throwing performance, and upper limb muscle volume. The risk of bias was evaluated using the PEDro scale. Means and standard deviations were used to calculate effect sizes, and the I2 statistic was used to assess heterogeneity. Publication bias was assessed using the extended Egger's test. Certainty of evidence was rated using the GRADE scale. Additional analyses included sensitivity analyses and adverse effects. RESULTS: Thirty-five studies were included in the systematic review and 30 studies in meta-analyses, involving 1412 male and female participants from various sport-fitness backgrounds. Training duration ranged from 4 to 16 weeks. Compared to controls, UBPT improved maximal strength (small ES = 0.39 95% CI = 0.15-0.63, p = 0.002, I2 = 29.7%), medicine ball throw performance (moderate ES = 0.64, 95% CI = 0.43-0.85, p < 0.001, I2 = 46.3%), sport-specific throwing performance (small ES = 0.55, 95% CI = 0.25-0.86, p < 0.001, I2 = 36.8%), and upper limbs muscle volume (moderate ES = 0.64, 95% CI = 0.20-1.08, p = 0.005, I2 = 0.0%). The GRADE analyses provided low or very low certainty for the recommendation of UBPT for improving physical fitness in healthy participants. One study reported one participant with an injury due to UBPT. The other 34 included studies provided no report measure for adverse effects linked to UBPT. CONCLUSIONS: UBPT interventions may enhance physical fitness in healthy youth and young adult individuals compared to control conditions. However, the certainty of evidence for these recommendations is low or very low. Further research is needed to establish the optimal dose of UBPT and to determine its effect on female participants and its transfer to other upper-body dominated sports.