Repeated-sprint sets test: a new method for evaluating and forecasting fitness in elite young male soccer players.

The objective of the current study was to explore the correlation between repeated sprint sets (RSS) ability and several physical attributes, including maximum sprint speed, maximal aerobic speed, maximal anaerobic speed, aerobic capacity, and explosive strength. Moreover, the aim was to assess the suitability of RSS as a comprehensive evaluation tool for physical qualities and to determine which physical field tests most accurately predict RSS in elite young male soccer players. A total of thirty-two young elite male soccer players (mean age 14.6 ± 0.3 years; predicted years from peak height velocity (PHV): - 0.4 ± 0.3; years in training: 3.7 ± 0.5) voluntarily participated in the study. The players participated in eight consecutive specific physical tests, with a minimum 72-h recovery between each session to minimize the impact of fatigue during the second trial. The participants completed the tests in the following order: RSS test, Vam-Eval test, a constant velocity test performed until exhaustion at 100% of vVO2max (tlim100), 20-m Multi-Stage Shuttle Run test (VMSRT), Yo-Yo Intermittent Recovery Test level 1 (Yo-Yo IR1), Maximal Anaerobic Shuttle Running Test (VMASRT), Maximal Sprinting Speed Test (20-m flying sprint), Countermovement Jump (CMJ), and Standing Long Jump test (SLJ). The results of the study showed that there were very large negative correlations between tlim100 and SST (sum of sprint times), and large negative correlations between Yo-Yo IR1, Vam-Eval, and SST during RSS in young elite male soccer players (p < 0.05). Additionally, VMASRT and SLJ demonstrated a moderate negative correlation with SST (p < 0.05). In contrast, significant positive correlations were found between 20-m flying sprint and the SST (p < 0.05). According to the stepwise multiple linear regression analysis, the primary predictors of SST, ranked by importance, were tlim100 and Yo-Yo IR1. These two predictors collectively accounted for 72% of the variance in players' SST (p < 0.0001). Due to the importance of aerobic capacity and short repeated accelerations/sprint sets for overall competitive performance in soccer, in conclusion, our results suggest that elite young male soccer players should perform both high intensity interval training and aeorobic capactity exercises as part of soccer training if the primary outcome is to improve repeated sprint ability performance.

High-Intensity Forward-Backward Plyometrics After the Warm-Up Entail Better Sprint and Change-of-Direction Performance Than Low-Intensity Side-to-Side Plyometrics.

This study aimed to determine the acute effects of high-intensity forward-backward and low-intensity side-to-side plyometric jumps performed following the warm-up on sprint (5, 10, and 15 m) and change-of-direction (COD) (T-half test and repeated T-half tests) performance in youth volleyball players. After a familiarization week, 30 male volleyball players (age = 12.04 ± 1.03 years) performed three randomized conditions (no-plyometrics, high-intensity plyometrics, and low-intensity plyometrics) in three sessions. In a within-subject design, three sets of six repetitions of forward-backward 30-cm hurdle jumps (high-intensity) and side-to-side 20-cm hurdle jumps (low-intensity) were completed. Sprint and COD were tested after each of the conditions with a 2-min rest. A significant effect of the plyometric condition was observed on sprint (p < .001, ηp2 range: .56-.70) and COD (p < .01, ηp2=.24), but not on repeated COD. More specifically, the high-intensity plyometric condition exhibited significantly better results compared with the low-intensity plyometric (Cohen's d range: 0.73-1.21) and control conditions (Cohen's d range: 0.91-2.21). Due to the importance of speed and COD in volleyball, these results suggest that young volleyball players may benefit from high-intensity forward-backward plyometric protocols following the warm-up to improve subsequent performance.

Effects of Aerobic and Speed Training Versus Active Control on Repeated Sprint Ability and Measures of Self-confidence and Anxiety in Highly Trained Male Soccer Players.

BACKGROUND: While there is ample evidence on the effects of single-mode aerobic and speed training on physical fitness in soccer players, less is known on the combined effects of these exercise regimens on physical and psychological factors. AIM: This study aimed to compare the effects of aerobic and speed training with soccer-specific training versus soccer-specific training only on aerobic performance during the YOYO intermittent fitness test level 1 (final velocity, total distance [TD], maximal oxygen consumption [VO2max]), repeated sprint ability (best, total sprint time [RSABT, RSATT], sprint decrement [RSA dec]) performance and somatic anxiety (SA), cognitive anxiety (CA), and self-confidence (SC) adaptations in soccer players. METHODS: Thirty-eight highly trained male athletes aged 18.9 ± 0.5 years were randomly assigned to an aerobic and speed training group (COMB-G; n = 20) or an active control group (CON-G; n = 18). Aerobic training comprised intermittent exercises at 110-120% of the final velocity achieved at the end of the YOYO IL1 test. Speed training involved maximal sprints over 15-20-m with 5-6 sets per session. Aerobic or speed training lasted 20 min per session and replaced parts of the soccer-specific training. CON-G performed the soccer-specific training including technical, tactical drills and small-sided games. Training volume was similar between groups. Pre, post intervention, all participants performed a repeated-sprint ability (RSA) test, the YO-YO IL1 test and the players completed a Competitive Scale Anxiety Inventory (CSAI-2). RESULTS: A two (group: COMB-G, CON-G) by two (time: pre, post) mixed ANOVA (group-by-time) was computed. Significant group-by-time interactions were found for RSATT (F = 117.3; p < 0.001; Pη2 = 1.78), RSABT (F = 82.4; p < 0.001; Pη2 = 1.53), final velocity (F = 85.8; p < 0.001; Pη2 = 1.53), TD (F = 87.1; p < 0.001; Pη2 = 1.56), and VO2max (F = 18.0; p < 0.001; Pη2 = 0.72). In addition, significant group-by-time interactions were observed for SC (F = 90.2; p < 0.001; d = 1.60), SA (F = 60.5; p < 0.001; Pη2 = 1.70), and CA (F = 20.7; p < 0.001; Pη2 = 0.75). Post-hoc analyses indicated significant improvements for all dependent variables from pre- to post-training in favor of COMB-G. CONCLUSION: Aerobic and speed training in combination with soccer-specific training is a safe and effective training method as it exerts positive effects not only for physical fitness but also for self-confidence and the coping of anxiety in male soccer players.

Preseason Integrative Neuromuscular Training Improves Selected Measures of Physical Fitness in Highly Trained, Youth, Male Soccer Players.

ABSTRACT: Hammami, R, Negra, Y, Nebigh, A, Ramirez-Campillo, R, Moran, J, and Chaabene, H. Preseason integrative neuromuscular training improves selected measures of physical fitness in highly trained, youth, male soccer players. J Strength Cond Res 37(6): e384-e390, 2023-This study examined the effects of an 8-week integrative neuromuscular training (INT) program, including balance, strength, plyometric, and change of direction exercises, on measures of physical fitness in youth male soccer players. Twenty-four male soccer players participated in this study. They were randomly allocated into an INT (n = 12; age = 15.7 ± 0.6 years, body height = 179.75 ± 6.54 cm, body mass = 78.20 ± 7.44 kg, maturity-offset = +2.2 ± 0.6 years) or an active control (CG, n = 12; age = 15.4 ± 0.8 years, body height = 178.4 ± 6.4 cm, body mass = 72 ± 8.3 kg, maturity-offset = +1.9 ± 0.7 years) group. Before and after training, tests to measure dynamic balance (Y-Balance test [YBT]), muscle strength (one repetition maximum [1RM]), muscle power (five jump test [FJT], single-leg hop test [SLHT], and countermovement jump [CMJ] height), linear sprint time (10 and 30-m), and change of direction with ball (CoDball) were performed. The analysis of covariance was used to test between-group differences (INT vs. CG) at posttest using baseline values as covariates. Significant, large, between-group differences at posttest were noted for the YBT (p = 0.016; d = 1.1), 1RM (p = 0.011; d = 1.2), FJT (p = 0.027; d = 1.0), SLHT (p = 0.04; d = 1.4), CMJ height (p < 0.001; d = 1.9), 10-m sprint (p < 0.01; d = 1.6), and CoDball (p < 0.05; d = 0.9) in favor of the INT group. Significant moderate-to-large pre-to-post changes were detected in the INT group for YBT, 1RM, CMJ height, SLHT, FJT, 10-m and 30-m sprint time, and CoDball test (d = 0.7 to 3.07, p < 0.05). No significant pre-to-post changes were observed in the CG (p > 0.05), except for 10-m sprint time (d = 1.3; p < 0.05). Exposure to INT twice weekly is effective and time efficient to improve various measures of physical fitness in highly trained youth male soccer players.

Exploring of two different equated instability resistance training programs on measure of physical fitness and lower limb asymmetry in pre-pubertal weightlifters.

BACKGROUND: Although previous research in pediatric populations has reported performance enhancements following instability resistance training, the effects of different volumes on measures of balance, strength and power and lower limb asymmetry remain unclear. OBJECTIVE: To compare the effect of two 8-week instability resistance training programs (IRT1: 2 sets x 8 repetitions, 20% one-repetition maximum (1RM); IRT2: 2 sets x 4 repetitions, 40% 1RM) in balance (center of pressure displacements), 1RM, single-leg jumps, and inter-limb asymmetry of prepubescent weightlifters. METHODS: Thirty-two male athletes (10.94 ± 0.47 yrs, 17.05 ± 0.14 kg/m2, and 6.44 ± 0.93% bodyfat) voluntarily participated and combined IRT (front and back squat, lunge, and deadlift) with their usual weightlifting training. Nonparametric tests evaluated the differences between pre- and post-intervention. RESULTS: Significant improvements were encountered in all the variables for both groups (effect sizes [ES] from 0.46 to 2.60), except the inter-limb asymmetry and the velocity of displacement of the center of pressure, which did not improve in IRT2. It is also worth highlighting that in the single-leg jumps and center of pressure displacements, whereas no significant differences were observed between IRT1 and IRT2 in the baseline, significant differences appeared in the follow-up measurements. CONCLUSION: IRT combined with weight-lifting training improves prepubescent weightlifters' performance; therefore, strength and conditioning coaches may consider including unstable devices with low loads into an overall conditioning program and warm-ups for prepuberal male weightlifters to promote their physical fitness and potentially decrease inter-limb asymmetry. TRIAL REGISTRATION: This study does not report results related to healthcare interventions using human participants; therefore, it was not prospectively registered.

The effects of different rehabilitation training modalities on isokinetic muscle function and male athletes' psychological status after anterior cruciate ligament reconstructions.

BACKGROUND: Previously, researchers reported performance enhancements following long-term plyometric training in athletes with anterior cruciate ligament reconstruction (LCA). However, the effects of combined eccentric and plyometric training on measures of isokinetic strength and psychological statues in male athletes have not been examined yet. Knowledge on the effects of combined eccentric and plyometric training help to better plan and program rehabilitations sessions and thus return-to-sports. OBJECTIVE: This study sought to compare the effects of three different rehabilitation training programs, eccentric training (ECC), plyometric training (PLYO), or combined eccentric and plyometric training (COMB), on psychological measures (kinesiophobia [TSK-CF], functional knee assessment, knee injury and osteoarthritis outcome score [KOOS], international knee documentation committee 2000 questionnaire [IKDC], and knee flexor and extensor isokinetic muscle performance (peak torque [PT], total work, ratio [R-HQ], and ratio of total work [R-TW]) at different angular velocities post ACL surgery in male elite athletes. METHODS: Forty elite male athletes from different sports (e.g., athletics, team sports) with ACL reconstruction participated in this study. The study started after a 14-weeks post-surgery rehabilitation program, which was identical for all subjects. After this initial rehabilitation period, athletes were randomly assigned to three experimental groups, ECC (n = 10), PLYO (n = 10), and COMB (n = 10), and a control group (CON: n = 10). Testing was conducted pre- and post-the 6-weeks intervention period and included the TSK-CF, KOOS, and IKDC. Peak torque of the knee extensors/flexors was tested at 90, 180, 240 °/s, after the 6-weeks training program only. RESULTS: Participants' adherence rate was 100% across all groups and none reported any training or test-related injury. No significant between-group baseline differences (pre-6-weeks intervention) were observed for any of the reported psychological and muscle strength parameters. Significant group-by-time interactions were found for TSK-CF (p = 0.001, d = 2.85), KOOS (p = 0.001, d = 1.31), and IKDC (p = 0.001, d = 1.07). The post-hoc analyses indicated that COMB showed larger pre-post improvements for all psychological variables (p < 0.001, d = 2.95 to 13.15), compared with PLYO, ECC, and CON. Contrast analyses demonstrated that COMB yielded significantly greater improvements compared with CON, PLYO, ECC for all isokinetic parameters at all three angular velocities (all p < 0.001, d = 0.99 to 4.61). CONCLUSION: The results showed that COMB induced greater gains for measures of psychological status and isokinetic muscle strength compared with single-mode PLYO and ECC in elite male athletes during a post-surgery ACL rehabilitation period. Accordingly, it is recommended to implement COMB as an effective rehabilitation means to improve knee function in male elite athletes. TRIAL REGISTRATION: This study does not report results related to health care interventions using human participants and therefore it was not prospectively registered.

Do verbal coaching cues and analogies affect motor skill performance in youth populations?

PURPOSE: The way coaching cues are worded can impact on the quality with which a subsequent motor skill is executed. However, there have been few investigations on the effect of coaching cues on basic motor skill performance in youths. METHOD: Across several international locations, a series of experiments were undertaken to determine the effect of external coaching cues (EC), internal coaching cues (IC), analogies with a directional component (ADC) and neutral control cues on sprint time (20 m) and vertical jump height in youth performers. These data were combined using internal meta-analytical techniques to pool results across each test location. This approach was amalgamated with a repeated-measures analysis to determine if there were any differences between the ECs, ICs and ADCs within the different experiments. RESULTS: 173 participants took part. There were no differences between the neutral control and experimental cues in any of the internal meta-analyses except where the control was superior to the IC for vertical jump (d = -0.30, [-0.54, -0.05], p = 0.02). Just three of eleven repeated-measures analyses showed significant differences between the cues at each experimental location. Where significant differences were noted, the control cue was most effective with some limited evidence supporting the use of ADCs (d = 0.32 to 0.62). CONCLUSION: These results suggest the type of cue or analogy provided to a youth performer has little subsequent effect on sprint or jump performance. Accordingly, coaches might take a more specific approach that is suited to the level or preferences of a particular individual.

The effect of combining HIIT and dry-land training on strength, technique, and 100-m butterfly swimming performance in age-group swimmers: a randomized controlled trial.

Combined interventions of pool-based and dry-land workouts are a common practice in swimming training. However, the effects on strength, technique and swimming performance are still not clear. Through a randomized controlled trial study, we investigated the effect of combining high intensity interval training (HIIT) and maximum strength training (MST) on strength, technique and 100-m butterfly swimming performance. Competitive age-group swimmers (N = 22, males) were randomly divided into two groups. The experimental group (EG: 14.1 ± 0.3 years old) performed 8 weeks of combined short-moderate HIIT and MST. The control group (CG: 14.5 ± 0.3 years old) subjects performed their usual training. Muscular strength, technique and swimming performance were evaluated before and after 8 weeks. Substantial improvements were observed in maximum muscle strength (mean diff: 22-28%; p < 0.001; d = 3.25-3.61), technique (p < 0.05; d = 0.98-1.96) and 100-m butterfly swimming performance (3.5%; p = 0.001; d = 1.81) when combining HIIT and MST during 8 weeks. Combining short-moderate HIIT and MST during 8 weeks can enhance maximum muscular strength, technique, and 100-m butterfly swimming performance. Coaches should adjust training programmes accordingly since it could yield important differences in swimming performance during competitions.

How effective are external cues and analogies in enhancing sprint and jump performance in academy soccer players?

This study investigated the effect of external (EC) and internal coaching cues (IC), analogies with a directional component (ADC) on sprint (20 m) and vertical jump performance in academy soccer players (n = 20). A repeated-measures analysis, with post-hoc comparisons, was used to identify any differences between these cues and a neutral (control) cue. Significant differences were found for both sprint (p < 0.001) and jump (p = 0.022) comparisons among cue types. In post-hoc analyses for the 20 m sprint, significant differences were observed between the EC and the IC, favouring the EC (p < 0.01, ES = 1.27 [CI: 0.24, 2.30]), and "away" ADC and the IC, favouring the "away" ADC (p < 0.01, ES = 1.21 [CI: 0.19, 2.22]). No other cues showed significant differences. For vertical jump, there was just one significant difference between comparisons, that being for the "away" ADC vs. the neutral cue, favouring the latter (p = 0.023, ES = 0.4 [CI: -0.04 to 0.84]). It appears that ECs and ADCs are most effective when coaching sprinting performance in academy soccer players. However, simply encouraging maximal effort from a youth athlete also appears to be a reasonable cueing strategy to drive performance in youth athletes.

The effect of volume equated 1- versus 2-day formats of Nordic hamstring exercise training on fitness in youth soccer players: A randomised controlled trial.

PURPOSE: This randomised controlled trial examined the effect of an 8-week volume-equated programme of Nordic hamstring exercise (NHE) training, executed at frequencies of 1- or 2-days per week, on fitness (10 m and 40 m sprint, '505' change of direction [COD] and standing long jump [SLJ]) in male youth soccer players (mean age: 16.4 ± 0.81 years). METHOD: Players were divided into an experimental group (n = 16) which was further subdivided into 1-day (n = 8) and 2-day (n = 8) per week training groups and a control group (n = 8). RESULTS: There were significant group-by-time interactions for 10-m sprint (p<0.001, η2 = 0.120, d = 2.05 [0.57 to 3.53]), 40-m sprint (p = 0.001, η2 = 0.041, d = 1.09 [-0.23 to 2.4]) and COD (p = 0.002, η2 = 0.063, d = 1.25 [-0.09 to 2.59). The experimental group demonstrated a 'very large' effect size (d = 3.02 [1.5 to 4.54]) in 10-m sprint, and 'large' effect sizes in 40-m sprint (d = 1.94 [0.98 to 2.90]) and COD (d = 1.84 [0.85 to 2.83). The control group showed no significant changes. There were no significant differences between the 1-day and 2-day training groups. In three of the four tests (40 m, COD, SLJ) the 2-day group demonstrated larger effect sizes. Ratings of perceived exertion (RPE) were significantly lower in the 2-day group (p<0.001, 3.46 [1.83 to 5.04). CONCLUSION: The NHE increases fitness in youth soccer players and there may be advantages to spreading training over two days instead of one.

A randomised controlled trial of 1- versus 2-day per week formats of Nordic hamstring training on explosive athletic tasks in prepubertal soccer players.

This randomised controlled trial examined the effect of volume-equated programmes of Nordic hamstring exercise (NHE) training, executed at frequencies of 1- or 2-days per week, on explosive athletic tasks (30 m sprint, 15 m manoeuvrability and standing long jump [SLJ]) in male youth soccer players (mean age: 10.3 ± 0.5 years). Players were divided into an experimental group (n = 31) which was further subdivided into 1-day (n = 16) and 2-days (n = 15) per week training conditions, and a control group (n = 14). There were significant group-by-time interactions for 30-m sprint (p < 0.001, d = 0.6), SLJ (p = 0.001, d = 1.27) and 15 m manoeuvrability (p < 0.001, d = 0.61). The experimental group demonstrated small to moderate effect sizes in 30-m sprint (d = 0.42, p = 0.077), SLJ (d = 0.97, p < 0.001) and 15 m manoeuvrability (d = 0.61, p < 0.001). The control group showed small significant performance decrements or no change in these variables. There were no significant differences between the 1-day and 2-day training groups. In two of the three tests (30 m sprint, SLJ) the 2-day group demonstrated larger effect sizes. The NHE enhances explosive athletic task performance in prepubertal youth soccer players and there may be only small advantages to spreading training over two days instead of one.

Bout duration and number of players of soccer small-sided games affect perceived enjoyment, physiological responses, and technical-tactical performance.

PURPOSE: To compare perceived enjoyment (PE), % of heart rate peak (%HRpeak), blood lactate (La), rating of perceived exertion (RPE), and technical-tactical performance of soccer players after four-a-side (4vs4) and three-a-side (3vs3) small-sided games (SSGs) with goalkeepers. METHODS: Sixteen males (20.7 ± 0.7 years; experience: 6.9 ± 1.2 years) completed and were measured after six sessions of SSGs (one twelve-minute bout (1x12), two six-minute bouts (2x6), and three four-minute bouts (3x4), both 3vs3 and 4vs4). Repeated measurements ANOVA evaluated significant differences (p ≤ 0.05). RESULTS: There was higher PE for 1 × 12 compared to 2 × 6 (effect sizes [ES] = 1.53 [3vs3 and 4vs4]) and 3 × 4 (ES = 3.13 [4vs4] and 4.16 [3vs3]). Continuous bout duration (1x12) was characterized by a significantly greater percentage of successful passes compared to 2 × 6 (ES = 2.57 [4vs4] and 1.79 [3vs3]) and 3 × 4 (ES = 2.14 [4vs4] and 1.73 [3vs3]), and minor ball loss rate (2x6: ES = 2.14 [4vs4] and 1.11 [3vs3]; 3x4: ES = 2.11 [4vs4] and 1.57 [3vs3]). The percentage of successful tackles was only significantly greater for 1 × 12 in 4vs4 (ES = 0.83 [2x6] and 0.86 [3x4]) and successful duels in 3vs3 (ES = 1.41 [2x6] and 1.43 [3x4]). Significantly greater %HRpeak for 1 × 12 compared to 2 × 6 (ES = 1.02 [4vs4] and 0.81 [3vs3]) and 3 × 4 (ES = 1.04 [4vs4] and 0.99 [3vs3]) was observed, La differences were only significant in 3vs3 (ES = 1.60 [2x6] and 1.30 [3x4]). Greatest RPE were encountered in 3 × 4 (4vs4) and 1 × 12 and 3 × 4 (3vs3). Significant differences existed between the 3vs3 and 4vs4 designs with a non-clear pattern of better results for neither of both. CONCLUSION: Therefore, coaches should consider longer continuous bouts when programming SSGs-based training to significantly increase PE, technical-tactical performance, and training load.

The Influence of Maturity Status on Dynamic Balance Following 6 Weeks of Eccentric Hamstring Training in Youth Male Handball Players.

Information about when to apply an appropriate eccentric hamstring strength training stimulus during long-term athlete development is essential for effective programming and improving balance performance. This study examined the effects of six-week eccentric hamstring training on dynamic balance performance in youth handball players of different maturity statuses (pre- or post-peak height velocity (PHV)). A randomized controlled design with 45 young male handball players (14.6 ± 0.3 years) from a local national handball club were randomly allocated to a 6 week, twice weekly eccentric hamstring training in two experimental groups: a pre-PHV (maturation offset: −2.13 ± 0.63, n = 10) and post-PHV (maturation offset: 0.79 ± 0.34, n = 12) group and two control groups: maturation offset: −2.09 ± 0.61, n = 10 and maturation offset: 0.55 ± 0.67, n = 13. Dynamic balance performance was evaluated by using the composite score during the lower quarter Y-balance test from pre- and post-intervention. A significant effect on balance scores was found from pre to post (F = 11.4; p = 0.002; η2p = 0.22), intervention (F = 5.4; p = 0.025; η2p = 0.12), and maturation (F = 369; p < 0.001; η2p = 0.9), but no significant interaction effects were found (F ≥ 3.3; p ≥ 0.077; η2p ≤ 0.07). Post hoc analysis revealed that the post-PHV group had a higher score than the pre-PHV group. Furthermore, that dynamic balance increased in the post-PHV group after intervention much more in the control post-PHV group. It was concluded that somatic maturation influences dynamic balance performance and that eccentric hamstring training results in greater improvement in balance performance in young male handball players for the post-pubertal group.

Effect of High-Volume Training on Psychological State and Performance in Competitive Swimmers.

This study aimed to examine the effect of four weeks of aquatic high-volume training (HVT) on the psychological state (somatic, cognitive anxiety, and self-confidence) and sprint swimming performance (50 m front crawl) compared to the standard training program (moderate volume training) in competitive swimmers. Twenty-eight male competitive swimmers participated in this study and were randomly allocated into two groups: HVT group (n = 14; age = 16.4 ± 0.31 years) and control group that underwent the standard training program (n = 14; age = 16.1 ± 0.30 years). All psychological state variables and swimming performance were measured in pre and post-test. Our findings showed a significant increase in anxiety state (34.13% to 45.83%; ES = 3.26 to 3.38) and a significant decrease in self-confidence (18.43%; ES = 2.39) after four weeks of HVT, while all psychological state variables remained unchanged in the control group (p > 0.05). In addition, our results showed no significant enhancement in swimming performance in both groups (p > 0.05). The sudden increase in training mileage negatively affected the anxiety, decreasing the state of self-confidence of the participants. In addition, four weeks of high training volume are insufficient to improve swimming performance. To conclude, gradually increasing the volume of the training load may be an adequate solution to promote adaptation to the effort, thus maintaining the stability of the psychological state of swimmers. In addition, it is recommended to integrate a concurrent mental preparation program with high-volume training to monitor the psychological state of competitive swimmers.

The Effects of Combined Verbal Encouragement and Technical Instruction on Technical Skills and Psychophysiological Responses During Small-Sided Handball Games Exercise in Physical Education.

To examine the effects of combined positive verbal encouragement and general technical guidelines on technical and psychophysiological parameters in pupils during a small-sided handball passing game. Twenty secondary school pupils (age, 16 ± 1 years; body mass, 55.3 ± 6.6 kg; body height, 1.77 ± 0.13 m; BMI, 22.6 ± 2.2 kg m-1) performed small-sided games (2 × 10 min) with three conditions: small-sided game (1) with combined verbal encouragement and technical instruction; (2) with technical instruction; (3) without any instruction (control) in which the passes for each pupil in each set was measured together with the rate of perceived exertion (RPE) and feeling mood after the first and second set. Results: A two-way analysis of variance demonstrated that the combined condition resulted in more passes compared to the technical instruction and control conditions, while the number of passes increased in set 2 for all conditions. RPE and the feeling mood were also differently between the conditions. Combined verbal encouragement and technical instruction during handball exercise were more beneficial for optimal passing numbers, positive mood with less perception of physical effort compared to only technical instruction and a control condition. The results evidenced positive acute effects of combined verbal encouragement and technical instruction during handball, indicating the usefulness of these training methods for optimal passing numbers, positive mood with less perception of physical effort in physical education pupils. Future studies should evaluate the applicability combined verbal encouragement and technical skills in the training of other conditioning capacities and the individual responsiveness of players toward verbal encouragement tasks.

Effects of 8-Week In-Season Contrast Strength Training Program on Measures of Athletic Performance and Lower-Limb Asymmetry in Male Youth Volleyball Players.

Strength training using high and lower load such as contrast training (CST) seems to be beneficial as it addresses larger adaptive reserves in youth athletes. Therefore, the aim of this study was to investigate the effects of CST on dynamic balance (composite score during dynamic balance test (CS-YBT)), one repetition maximum lower-limb back squat (1RM), jumping performance (single-leg hop (SLH) or countermovement jump height (CMJ)), lower-limb asymmetry (predicted from the single-leg jump performance between two legs [ILA]) in elite youth male volleyball players. Thirty-one male youth volleyball players aged 14 years were randomly assigned to a CST group (n = 16) or a control group (n = 15). The tests were performed before and after 8 weeks of training. Significant group × time interactions was observed for CS-YBT [p < 0.001, ηp2 = 0.70], 1RM [p < 0.001, ηp2 = 0.95], SLH with right and left leg [p < 0.001, ηp2 = 0.69 and 0.51], CMJ [p < 0.001, ηp2 = 0.47]), whilst it was not notable in ILA [p < 0.294]. Post hoc tests showed that CST group demonstrated greater improvement in all of the dependent variables from medium to large effect size (for all p < 0.001). As a result, 8 weeks of CST twice a week can be an effective and efficient training along with volleyball training to improve skill-related fitness measures, except for lower-limb asymmetry in young volleyball players.

An eight-weeks resistance training programme with elastic band increases some performance-related parameters in pubertal male volleyball players.

The main aim was to evaluate the changes in dynamic, reactive, and power strength, and balance (as volleyball performance-related parameters) in pubertal volleyball players when a part of their normal inseason training regimen was replaced by an elastic band training (EBT). 27 male elite volleyball players were randomly allocated to intervention (N = 14; 14.86 ± 0.52 years) or control group (N = 13; 14.74 ± 0.36 years). The intervention consisted of an 8-week EBT program focused on the training of the lower limb, with different volumes and intensities. Countermovement jump (CMJ) and standing long jump (SLJ) were used to assess the power strength, squat one repetition-maximum, and reactive strength index to assess dynamic and reactive strength, respectively. Also, the balance was assessed through different parameters of the foot centre of pressure (CoP) displacements obtained with a force platform. An ANOVA of repeated measurements and post-hoc tests evaluated differences between groups and between baseline and post-intervention. Dynamic and power (CMJ and SLJ) strength, and anteroposterior displacement of the CoP were improved after the intervention. The control group only improved the dynamic strength. No statistically significant difference (p > 0.05) were found in the rest of the variables. EBT improves jump performance and other volleyball performance-related parameters in adolescent male athletes and should be considered to complement regular volleyball in-season training.

Effect of Concurrent Resistance Training on Lower Body Strength, Leg Kick Swimming, and Sport-Specific Performance in Competitive Swimmers.

The present study investigated the effect of 9 weeks of combined resistance training (aquatic and dry land resistance) on maximum lower body strength, leg kick, and swimming performance in competitive swimmers. Twenty-two male national competitive swimmers were randomly assigned into two groups: experimental group (EG: age = 16.2 ± 0.3 years) or control group (CG: age = 16.3 ± 0.3 years). The EG performed a combined resistance training while the CG group completed their usual training. One repetition maximum (1RM) back squat, 30 m leg kick, and swimming performance (100 m front crawl, start and turn) were evaluated in pre and post test. The findings showed a significant increase in 1RM back squat (d = 1.90; 14.94 ± 1.32%) after 9 weeks of combined resistance training. In addition, ours results revealed a significant improvement in 30 m leg kick swimming (d = 2.11; 5.84 ± 0.16%) and in all swimming, start and turn performances (d = 1.83 to 2.77; 2.69 ± 0.18% to 15.14 ± 1.06%) in EG. All dependent variables remained unchanged in the CG. To sum up, 9 weeks of combined resistance training can improve the maximum lower body strength and leg kick swimming performance. These improvements can be the essential factors that subsequently positively affected swimming, start and turn performances. Combined resistance training is an effective training that can be incorporated by coaches and swimmers into their programs to improve strength, leg kick swimming, and, subsequently, swimming performance in competitive swimmers.

Acute effects of maximal versus submaximal hurdle jump exercises on measures of balance, reactive strength, vertical jump performance and leg stiffness in youth volleyball players.

Background: Although previous research in pediatric populations has reported performance enhancements following long-term plyometric training, the acute effects of plyometric exercises on measures of balance, vertical jump, reactive strength, and leg stiffness remain unclear. Knowledge on the acute effects of plyometric exercises (i.e., maximal versus submaximal hurdle jumps) help to better plan and program warm-up sessions before training or competition. Objectives: To determine the acute effects of maximal vs. submaximal hurdle jump exercise protocols executed during one training session on balance, vertical jump, reactive strength, and leg stiffness in young volleyball players. Materials and methods: Thirty male youth volleyball players, aged 12-13 years, performed two plyometric exercise protocols in randomized order. In a within-subject design, the protocols were conducted under maximal (MHJ; 3 sets of 6 repetitions of 30-cm hurdle jumps) and submaximal (SHJ; 3 sets of 6 repetitions of 20-cm hurdle jumps) hurdle jump conditions. Pre- and post-exercise, balance was tested in bipedal stance on stable (firm) and unstable surfaces (foam), using two variables [center of pressure surface area (CoP SA) and velocity (CoP V)]. In addition, the reactive strength index (RSI) was assessed during countermovement maximal jumping and leg stiffness during side-to-side submaximal jumping. Testing comprised maximal countermovement jumps (CMJ). Results: Significant time-by-condition interactions were found for CoP SA firm (p < .0001; d = 0.80), CoP SA foam (p < .0001; d = 0.82), CoP V firm (p < .0001; d = 0.85), and CoP V foam (p < .0001; d = 0.83). Post-hoc analyses showed significant improvements for all balance variables from pretest to posttest for MHJ but not SHJ. All power tests displayed significant time-by-group interactions for countermovement jumps (p < .05; d = 0.42), RSI (p < .0001; d = 1.58), and leg stiffness (p < .001; d = 0.78). Post-hoc analyses showed significant pre-post CMJ (p < .001, d = 1.95) and RSI (p < .001, d = 5.12) improvements for MHJ but not SHJ. SHJ showed larger pre-post improvements compared with MHJ for leg stiffness (p < .001; d = 3.09). Conclusion: While the MHJ protocol is more effective to induce acute performance improvements in balance, reactive strength index, and vertical jump performance, SHJ has a greater effect on leg stiffness. Due to the importance of postural control and muscle strength/power for overall competitive performance in volleyball, these results suggest that young volleyball players should implement dynamic plyometric protocols involving maximal and submaximal hurdle jump exercises during warm-up to improve subsequent balance performance and muscle strength/power.

Effects of Game Weekly Frequency on Subjective Training Load, Wellness, and Injury Rate in Male Elite Soccer Players.

To compare the effects of playing one or two games per week on subjective perceived exertion (RPE) and (RPE-based) training load, monotony index, sleep, stress, fatigue, and muscle soreness (Hooper index), total mood disturbance, and injury rate in elite soccer players. Fourteen males from a first-division soccer club (age: 24.42 ± 4.80 years) competed in two games per week for six weeks and one game per week for twelve weeks (a total of 24 games). Paired t-tests and non-parametric Wilcoxon signed ranks evaluated the significance of the differences (p < 0.05). The main findings were that RPE was significantly larger when playing two games per week compared with one game. However, subject total and mean training load, mood disturbance, monotony, and subjective perception of sleep, stress, fatigue, muscle soreness monitoring (Hooper index), and the number of injuries were not different. The findings suggested that competing in two matches per week does not negatively influence injury rate and players' perceptions of training load or wellness, even though players perceive two games per week as more physically demanding compared with one game per week.