Physiological Responses of the Modified Shuttle Test in Adults With Cystic Fibrosis

International audienc

Resistance Training and Handball Players’ Isokinetic, Isometric and Maximal Strength, Muscle Power and Throwing Ball Velocity: A Systematic Review and Meta-Analysis

Purpose: Handball (Team Handball) is an intermittent and strenuous contact sport, the successful performance of which depends on frequent body contacts, and the ability to make repeated explosive muscular contractions required for jumping, acceleration, sprinting, turning, changing pace, and throwing a ball. Many studies have investigated the effect of resistance training (RT) in handball players, however with conflicting results. Therefore, our objective was to investigate the impact of RT on maximal strength (isometric and isokinetic strength), the power of both lower and upper limbs, and throwing velocity, in handball players. Methods: A comprehensive literature search yielded a pool of 18 studies, which were retained in the systematic review and meta-analysis. Results: A total of 275 handball players were included. The overall effect size (ES) of RT was 0.996 ([95%CI 0.827–1.165], p = 0.0000). At the multivariate meta-regression, the effect of publication year was significant, as well as the effects of country, gender, and level. The impact of RT on isokinetic strength was not significant (ES 0.079 [95%CI −0.060–0.219], p = 0.265), whereas the impact of RT on throwing (ES 1.360 [95%CI 0.992–1.728], p = 0.000) was significant, as well as the effects of RT on isometric strength (ES 0.398 [95%CI 0.096–0.700], p = 0.010), on maximal strength (ES 1.824 [95%CI 1.305–2.343], p = 0.000), and on power (ES 0.892 [95%CI 0.656–1.128], p = 0.000). Conclusions: RT has a significant impact in handball players. Handball coaches could design conditioning protocols and programs based on our results. However, due to a number of shortcomings, including the high, statistically significant heterogeneity among studies and the evidence of publication bias, further high-quality investigations are needed

Data concerning isometric lower limb strength of dominant versus not-dominant leg in young elite soccer players

The present data article describes the isometric lower limb strength of dominant leg versus not-dominant leg measured with handheld dynamometer (HHD) in a sample of 31 young elite soccer players (age 16.42 ± 0.45 years; height 169.00 ± 0.50 cm; leg length 94.80 ± 3.32 cm; body-mass 67.04 ± 5.17 kg). Keywords: Lower limb strength, leg, Not-dominant leg, Handheld dynamometer, Soccer player

Effect of leg dominance on change of direction ability amongst young elite soccer players

Young soccer players often use one particular dominant leg (DL) to perform dynamic movements which require strength, resulting in leg asymmetry. The aim of this study was to compare, in young soccer players, the effect of using DL and non-dominant leg (NDL) on time performance of two change of direction (COD) manoeuvres in several angles of COD. Seventy-three young male soccer players (mean ± SD, age: 16.1 ± 1.8 year) participated in this study. Players performed 10-m sprints, either in a straight line or with a COD (5 m straight ahead and a turn of 45°, 90°, 135° and 180° to the opposite side of the DL or NDL). Testing for COD speed was conducted over two different manoeuvres: (1) sidestepping and (2) bypass. Maximal isometric voluntary contraction of the knee extensors/flexors and hip abductors/adductors was also measured using a handheld dynamometer. For sidestepping, COD performance with use of the DL was significantly better compared to the NDL (P < 0.05) in all angles of COD. However, bypass COD performance through use of the DL was better compared to the NDL only when turning at 135°. Additionally, strength of the knee extensors/flexors and hip abductors of the DL was significantly (P < 0.05) greater than the NDL. The use of the DL allows better COD performance than the NDL when sidestepping manoeuvre is used. However, the DL allows better COD performance than the NDL only at 135° with the use of the bypass manoeuvre. Furthermore, the greater strength of the DL compared to the NDL may contribute to COD performance difference between legs

Analysis of positional training loads (ratings of perceived exertion) during various-sided games in European professional soccer players

The primary aim of the study was to perform a comparative analysis of the positional training loads during various game formats among European professional soccer players. Twenty-two male professional soccer players participated in the investigation and were divided into their tactical positional roles for analysis. Ratings of perceived exertion were collected daily and corresponded to specific formatted game types (small-sided games; large-sided games; large-sided games within a smaller area size) implemented as part of the weekly periodised training structure. Across the sample period, only one game per week training scenarios were analysed (9 small-sided games; 9 large-sided games; 9 large-sided games within a smaller area size). Analysis of the mean ratings of perceived exertion between various game formats revealed significant differences between large-sided games within a smaller area size vs. small-sided games (5.53 vs. 7.79; p ¼ 0.007); however, no differences were presented between small-sided games vs. large-sided games format types (7.9 vs. 7.35; p > 0.05). No differences between mean ratings of perceived exertion and small-sided games and large-sided games, respectively, were found. Differences were shown between positional demands during large-sided games within a smaller area size game type formats, with wide forwards reporting higher mean ratings of perceived exertion values when compared against centre forwards (p ¼ 0.02). Therefore, within a periodised microcycle, variance of game formats can be used to manipulate training loads, manage accumulation of fatigue through a tapering method in order to facilitate optimal match preparation. Furthermore, players of certain position types may require additional training stimulus to induce the desired physical adaptations.

Production laitière sous les conditions méditerrannènnes: Cas de la Tunisie

peer reviewe

'Side-stepping maneuver': not the more efficient technique to change direction amongst young elite soccer players

Two change of direction (COD) maneuvers (Side-Stepping [SSJ and Crossover-Stepping [CR) are often described in the scientific literature. However, there are other COD techniques which have not been investigated Therefore, the main aim of this study was to compare the performance of SS maneuver and a “By-Pass” (BP) COD maneuver (multiple short steps to avoid reduction in running speed by performing longer distance and wider angle of COD compared to SS) over several angles of COD. Seventy-three male soccer players (from U15 and U18 categories) competing at youth level participated in the study. Each age-category was divided into Starters Players (SP) and Non-Starters Players (NSP). Players performed a total of 26 sprints of 10-m, either in straight-line or with a COD (5 m straight ahead and the other 5 m with a turn of 45°, 90°, and 135°) using the two different maneuvers separately: SS and BP. Sprint performance was significantly better at 45°, 90° and 135° CODs (p<0.001) when players performed a BP maneuver compared to SS. Significant age-group effects were revealed, with U18 players demonstrating better performances (p<0.001) than U15 players in all COD angles. Further analysis revealed a significant effect of playing-level, with SP having better performances (p<0.002) compared to NSP in all COD angles. It can be concluded that the BP is a more effective maneuver than SS for changing direction in youth elite soccer players. Also, COD tests with angles ranging between 45° and 135° discriminate between Starters and Non-starters in youth soccer

Effect of post-activation potentiation induced by one, two or three half-squats on repeated sprint acceleration performance

Introduction: The aim of this study was to analyze the effect of different post-activation potentiation (PAP) protocols on initial-acceleration (0-10 m) and late-acceleration phases (10 to 30 m) within a repeated sprint ability (RSA) test. Methods: Twenty athletes (age: 20.8±1.2 years, height: 180.2±5.3 cm, body mass: 76.8±6.4 kg, % body fat: 10.9±2.8, and 3 repetition maximum [3-RM] of half-squats 152.9±14.8 kg) completed 4 testing sessions of RSA testing (7x30-m sprints, starting every 25s, with an active recovery inbetween). Five minutes before the RSA-testing, conditioning protocols were performed: I) one halfsquats at 90% of 1 repetition maximum (1RM) [PAP1]; II) two half-squats at 90% of 1RM [PAP2]; III) three half-squats at 90% of 1RM [PAP3], and (IV) the control protocol [CON]: no effort. Each conditioning condition was applied in a counterbalanced, randomized order on separate days separated by a minimum of 72 hours’ rest. Results: ANOVA showed that PAP1 and PAP2 sessions were similar, and brought significantly improved results for: 0-30m and 0-10m sprints of the RSA-time (p[removed]0.05, ES=small). Furthermore, magnitude-based inference revealed that both PAP1 and PAP2 protocols elicited changes >75% likelihood of exceeding the smallest worthwhile change (>99% likely) for mean sprint-time (RSAmean) and the percentage of sprint-decrement (RSAdec) in overall 0-30 m and 0-10 m of the RSA test. Conclusion: PAP1 and PAP2 exert a positive effect on the initial-acceleration phase of the RSA and could be considered in the preparation routine of repeated sprinting activities. © 2018, CIC Edizioni Internazionali s.r.l. All rights reserved.Scopu

Dynamic balance ability in young elite soccer players:implication of isometric strength

BACKGROUND: Soccer requires maintaining unilateral balance when executing movement with the contralateral leg. Despite the fact that bal-ance requires standing with maintaining isometric posture with the support leg, currently there is a lack of studies regarding the implication of isometric strength on dynamic balance's performance among young soccer players. Therefore, the aim of this study was to examine the relation-ship between the Y-Balance Test and 12 lower limbs isometric strength tests. METHODS: Twenty-six right footed soccer players (mean±SD, age=16.2±1.6 years, height=175±4.2 cm, body mass=68.8±6.1 kg) performed a dynamic balance test (star excursion balance-test with dominant- (DL) and nondominant-legs (NDL). Furthermore, maximal isometric contrac-tion tests of 12 lower limb muscle groups were assessed in DLand NDL. RESULTS: Correlations analysis reported a significant positive relationship between some of isometric strength tests (with DL and NDL) and the Y-Balance Test. Furthermore, stepwise multiple regression analysis showed that maximal isometric strength explained between 21.9% and 49.4% of the variance of the Y-Balance Test. Moreover, maximal isometric strength was dependent upon the reaching angle of the Y-Balance Test and the leg used to support body weight. CONCLUSIONS: This study showed a significant implication of maximal isometric strength of the lower limb and the Y-Balance Test. Moreo-ver, the present investigation suggests the implementation of specific lower limb strengthening exercises depending on players' deficit in each reaching direction and leg. This result suggests that further studies should experiment if increasing lower limbs isometric strength could improve dynamic balance ability among young soccer players. © Copyright 2018 Edizioni Minerva Medica.Scopu