218 research outputs found

    Peaking for the World Para Athletics Championships: Case study of a World Champion female Paralympic shot putter

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    Tapering is used to maximize performance and reduce fatigue levels before athletic competitions. However, scientific evidence regarding Paralympic athletes is scarce. Moreover, no study has assessed the effects of tapering practices on performance in a world champion female Paralympic shot putter (FPSP). Therefore, the aim of this study was to assess the effects of a short tapering period on the performance of an elite FPSP. A world champion FPSP (sport class F54; age 42.2 y; body mass 74 kg; height 1.67 m) was monitored during both overload (2 weeks) and tapering (2 weeks; training volume and intensity decreased) blocks previous to Dubai 2019 World Para Athletics Championships. The internal training load (ITL) (through session rating of perceived exertion) and self-reported wellbeing (using a questionnaire) were assessed daily. Shot put performance was assessed at the beginning and after tapering. The ITL decreased 37.9% with tapering, shot put performance increased 7.6%, there were no differences between weekly wellness scores. No significant correlations were found between ITL and wellbeing indicators. It was concluded that two weeks of tapering induced a rather large improvement in shot put performance. Surprisingly, self-reported wellbeing did not improve with taper as expected

    Effects of a mobility and dynamic strength intervention program on the range of motion, strength, and strength asymmetry in people with neck or low back pain

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    The purpose was to ascertain the effects of a 12-week intervention program based on exercises of mobility and dynamic strength on the stabilization of neck and trunk muscles in people with neck or low back pain according to gender. Forty-two subjects (n = 25 males and n = 17 females; age 49.62±8.82 years) with neck or low back pain completed a recovery-training program focused on improving mobility and strength in the stabilizing muscles of the trunk and neck. A range of motion test, a strength (maximum voluntary contraction) test and the muscle strength asymmetry of the muscle groups analyzed were assessed at the beginning (T1), after six (T2) and after 12 (T3) weeks of intervention. Improvements were seen in nine out of the 12 range of motion variables at T2 (ES=0.52 to 1.26, moderate-high; p<.05) and T3 (ES=-0.28 to -0.44, low; p<.05 or p<.01). Improvements were also evident in all the strength variables at T2 (ES=-0.81, high; p<.01) and T3 (ES=-1.08 to -0.95, high; p<.01). In contrast, in the strength asymmetry variables improvements were found in one out of the five variables analyzed at T2 (ES=-0.81, high; p<.01) and two out of five at T3 (ES=- 1.08 to -0.95, high; p<.01). In conclusion, the intervention was effective for improving range of motion and strength. However, to improve muscle strength asymmetry it may be necessary to include specific exercises

    Effects of caffeine, beetroot juice and its interaction consumption on exercise-related fatigue

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    The aim of this study was to analyze the effect of different supplementation conditions on fatigue and performance in flywheel half-squat tests in senior men. Sixteen active males (age: 22.8±4.9 years; body mass index: 23.7±2.4 kg*m-2) participated in the intervention during a 4-week period. Four experimental conditions were established using a double-blind design: placebo, caffeine (CAF), beetroot juice (BRJ), and combined BRJ+CAF. To assess the effect of supplementation, participants completed a countermovement jump (CMJ) before (Pre), 30 s after (Post-30s) and 180 s after (Post-180 s) completing a flywheel half-squat exercise protocol (four sets of eight all-out repetitions, with a 3-min inter-set rest, using different inertial loads). Additionally, the mean power output during the flywheel half-squat protocol was recorded. A repeated measures ANOVA showed greater mean power (~1000 W, p<.001) produced in flywheel exercise after the CAF, BRJ and BRJ+CAF consumption compared to the placebo condition. After placebo, CAF and BRJ, CMJ performance at Post-180 s was reduced compared to Pre (p=.003-.087, two-way ANOVA; ES=-0.39/-0.49), although no significant performance reduction (p=.087) was noted after BRJ+CAF. In conclusion, compared to placebo, CAF, BRJ, and BRJ+CAF allow greater total mean power in the flywheel half-squat power test, although without effects on exercise-related fatigue. Additionally, BRJ+CAF improved recovery after a high demanding power-production protocol

    an education review on funnel plot-based methods

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    Publication bias refers to a systematic deviation from the truth in the results of a meta-analysis due to the higher likelihood for published studies to be included in meta-analyses than unpublished studies. Publication bias can lead to misleading recommendations for decision and policy making. In this education review, we introduce, explain, and provide solutions to the pervasive misuses and misinterpretations of publication bias that afict evidence syntheses in sport and exercise medicine, with a focus on the commonly used funnel-plot based methods. Publication bias is more routinely assessed by visually inspecting funnel plot asymmetry, although it has been consistently deemed unreliable, leading to the development of statistical tests to assess publication bias. However, most statistical tests of publication bias (i) cannot rule out alternative explanations for funnel plot asymmetry (e.g., between-study heterogeneity, choice of metric, chance) and (ii) are grossly underpowered, even when using an arbitrary minimum threshold of ten or more studies. We performed a cross-sectional meta-research investigation of how publication bias was assessed in systematic reviews with meta-analyses published in the top two sport and exercise medicine journals throughout 2021. This analysis highlights that publication bias is frequently misused and misinterpreted, even in top tier journals. Because of conceptual and methodological problems when assessing and interpreting publication bias, preventive strategies (e.g., pre-registration, registered reports, disclosing protocol deviations, and reporting all study fndings regardless of direction or magnitude) ofer the best and most efcient solution to mitigate the misuse and misinterpretation of publication bias. Because true publication bias is very difcult to determine, we recommend that future publications use the term “risk of publication bias”.9E1A-F9DD-3EB8 | Filipe Manuel ClementeN/

    Interaction of kinematic, kinetic, and energetic predictors of young swimmers’ speed

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    The aim of this study was to assess the interaction of kinematic, kinetic, and energetic variables as speed predictors in adolescent swimmers in the front-crawl stroke. Design: Ten boys (mean age [SD] = 16.4 [0.7] y) and 13 girls (mean age [SD] = 14.9 [0.9] y) were assessed. Methods: The swimming performance indicator was a 25-m sprint. A set of kinematic, kinetic (hydrodynamic and propulsion), and energetic variables was established as a key predictor of swimming performance. Multilevel software was used to model the maximum swimming speed. Results: The final model identified time (estimate = −0.008, P = .044), stroke frequency (estimate = 0.718, P < .001), active drag coefficient (estimate = −0.330, P = .004), lactate concentration (estimate = 0.019, P < .001), and critical speed (estimate = −0.150, P = .035) as significant predictors. Therefore, the interaction of kinematic, hydrodynamic, and energetic variables seems to be the main predictor of speed in adolescent swimmers. Conclusions: Coaches and practitioners should be aware that improvements in isolated variables may not translate into faster swimming speed. A multilevel evaluation may be required for a more effective assessment of the prediction of swimming speed based on several key variables rather than a single analysisThis work is supported by national funds (FCT–Portuguese Foundation for Science and Technology) under the project UIDB/DTP/04045/2020.info:eu-repo/semantics/publishedVersio

    Effects of short-term strength and jumping exercises distribution on soccer player’s physical fitness

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    The aim of this study was to examine the effects of a short-term (six weeks) preseason strength and jumping exercises distribution program on amateur adult soccer player’s indicators of physical fitness. Twenty male athletes (age 20.1±1.6 years) were randomly divided into two groups that completed a volume-equated training program differing only in exercises distribution: a group that completed three weeks of strength followed by three weeks of plyometric training (TT; n=10) and a group that completed six weeks of combined strength and plyometric drills (S+P; n=10). Athletes completed a triple hop test with the dominant (HOPd) and non-dominant leg (HOPnd), a 15 meters sprint, a change of direction speed (CODS) test (i.e. T test), and a 6×30 meters repeated sprint with change of direction for the best (RSCODb) and mean velocity (RSCODm), and the percentage of decrement (%Dec) in sprint time. Moreover, athletes performed a squat test for maximal power. Both strength and jumping training programs were performed two times per week, equated for exercises, frequency, volume, and intensity per session. The TT group completed the strength training volume during the first three weeks, and the plyometric training volume in the last three weeks, while the S+P combined strength and plyometric training during the six weeks. A 2 (group) × 2 (time: pre, post) ANOVA with repeated measures was used for statistical analysis. Analyses revealed significant improvements for the TT and S+P (HOPd: ES=0.91, 10.28 and 16.69%, respectively; HOPnd: ES=0.86, 11.49 and 14.71%, respectively; RSCODb: ES=0.84, 9.23 and 8.34%, respectively; RSCODm: ES=0.89, 8.56 and 7.51%, respectively). In the post-test there were no significant differences between the groups in any variable analyzed. In conclusion, both training approaches were equally effective at improving jumping and repeated sprinting ability. However, only after the S+P training approach a significant improvement in CODS was observed, with more substantial changes in maximal sprinting speed

    Influence of Maturation Status on Eccentric Hamstring Strength Improvements in Youth Male Soccer Players following the Nordic Hamstring Exercise

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    Purpose: This study examined the effects of a 6-week nordic hamstring exercise (NHE) program in youth male soccer players of less mature (Pre-Peak Height Velocity [PHV]) or more mature (Mid/Post-PHV) status. Methods: Forty-eight participants were separated into Pre-PHV (11.0 ± 0.9yrs) or Mid/Post-PHV (13.9 ± 1.1) groups and further divided into experimental (EXP) and control (CON) groups with eccentric hamstring strength assessed (Nordbord) both pre and post the training program. Participants in the EXP groups completed a periodised NHE program performed once or twice weekly over a 6-week period. Results: The NHE programme resulted in moderate and small increases in relative eccentric hamstring strength (N.kg-1) in the Pre-PHV EXP (d = 0.83 [0.03 - 1.68]) and Mid-PHV EXP (d = 0.53 [-0.06 - 1.12]) groups respectively. Moderate increases in the same measure were also seen in the between-group analyses in the Pre-PHV (d = 1.03 [0.23 - 1.84]) and Mid-PHV groups (d = 0.87 [0.22 - 1.51]), with a greater effect observed in the former. Conclusion: The results from this study demonstrate that a 6-week NHE program can improve eccentric hamstring strength in male youth soccer players with less mature players achieving mostly greater benefits. The findings from this study can aid in the training prescription of the NHE in youth male soccer players

    a systematic review and meta-analysis

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    Purpose: To determine the effects of maturation stage (eg, classified in the same intervention protocol as early-, and late-mature) on linear sprinting speed adaptations to plyometric jump training (PJT) in youth (aged <18 years) male team sports players. Patients and Methods: Eligibility criteria was determined based on PICOS: (P) healthy youth male team sport players classified in the same intervention protocol in ≄2 maturation-related categories, based on a recognized maturation stage-determination method, including (but not limited to) Tanner stage; peak height velocity (eg, Mirwald method); radiography-based method (eg, Fels method); (I) athletes exposed to PJT with a minimum of 4 weeks duration; (C) athletes non-exposed to PJT (non-dedicated intervention, ie, only field-based regular training) or performing a parallel intervention not-related with PJT organized by maturation levels; (O) sprinting speed (eg, time, maximal sprint speed) measured in any linear sprint test trajectories before and after the intervention; (S) only randomized controlled and/or parallel trials. Searches were conducted on December 2021 in EMBASE, PubMed, Scopus, SPORTDiscus and Web of Science, restricted to Portuguese, Spanish and English languages, with no restrictions regarding publication date, and no filters applied. The PEDro scale was used to assess the risk of bias in the included studies. Meta-analysis was computed using the inverse variance random-effects model. The significance level was set at p < 0.05. Results: The search identified 1219 titles. From those, four studies were selected for qualitative and quantitative synthesis. Four studies provided data for sprinting performance, involving 10 experimental and 8 control groups showing a small effect of trained participants on sprinting performance (ES = 0.31; p = 0.064; I2 = 41.3%) when compared to controls. No significant moderator effect was noted for somatic maturity (p = 0.473 between groups). Conclusion: PJT had no significant effect on sprinting performance, although the inclusion criteria partially may explain that.9E1A-F9DD-3EB8 | Filipe Manuel ClementeN/

    Vertical Jumping as a Monitoring Tool in Endurance Runners: A Brief Review

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    Jumping performance (e.g., countermovement jump [CMJ]), as a measure of neuromuscular performance, has been suggested as an easy-to-use tool which simultaneously provides neuromuscular and metabolic information and, thereby, allows coaches to confidently monitor the status of their athletes during a workout. This hypothesis has been satisfactorily tested with sprint athletes. However, the rationale for the use of CMJ height loss as an index to monitor the workload during an endurance running session is not sufficiently evidence-based. First, it is assumed that a CMJ height loss occurs during typical interval training for endurance runners. Second, it is also assumed that a significant relationship between metabolic stress and the neuromuscular strain induced during these endurance workouts exists. These two assumptions will be questioned in this review by critically analyzing the kinetics of CMJ performance during and after running workouts, and the relationship between neuromuscular and physiological stress induced during different protocols in endurance runners. The current evidence shows that fatigue induced by common running workouts for endurance runners does not counterbalance the potentiation effect in the CMJ height. Additionally, the findings reported among different studies are consistent regarding the lack of association between CMJ height loss and physiological stress during interval sessions in endurance runners. In practical terms, the authors suggest that this marker of neuromuscular fatigue may not be used to regulate the external training load during running workouts in endurance runners. Nevertheless, the analysis of CMJ height during running workouts may serve to monitor chronic adaptations to training in endurance runners