A 3-min weighted vests re-warmups induce sprint performance enhancements at the start of the second half of a soccer match-play.

Purpose: This study aimed to investigate the effect of re-warm-up (RWUP) activities consisting of three sets of 15-m sprints with weighted vests on 20-m sprint performance after the break. Methods: Using a randomized, and counterbalanced cross-over design, twenty U15 elite soccer players performed four RWUP trials which consisted of 15-min of passive rest (control: CONT), 3 × 15-m sprint (RW0%), sprinting with a vest-loaded at 5% of body-mass (BM) (RW5%), sprinting with a 10% BM vest (RW10%). The 3-min RWUP protocols started 10-min after the commencement of the 15-min between-halves break and concluded 2-min before its end. During each testing session, the participant's RPE scores, and 20-m sprint performance were registered before the first half, and at the end of the break of the simulated match-play. Results: Significant time effects [F (1.72) = 54.37, d = 1.88, p < 0.001; F (1.72) = 9.07, d = 0.77, p = 0.003], and condition effects [F (3.72) = 11.81, d = 1.53, p < 0.001; F (3.72) = 7.36, d = 1.21, p = 0.003] were observed for RPE scores and 20-m sprint performance, respectively. Significant condition-by-time interactions were found for RPE scores (p < 0.003, d = 0.54), and 20-m sprint performance (p < 0.002, d = 0.70). Contrast analysis showed significantly higher RPE scores (p < 0.001, d = 1.55), and improved 20-m sprint performance (p = 0.0004, d = 1.19) in the RW10% condition compared to all other conditions. Conclusion: Sprinting for 3-min with a 10% body-mass vest resulted in the highest RPE scores and the most substantial enhancements in 20-m sprint performance. Young elite soccer players should incorporate 10% body-mass weighted vests in their re-warm-ups to boost post-break sprint performance.

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.

Short-term in-season ballistic training improves power, muscle volume and throwing velocity in junior handball players. A randomized control trial.

This study investigated the effects of a ballistic training programme using an arm/shoulder specific strength device (ASSSD) on the upper body peak power (PP), muscle volume (MV) of the dominant arm and throwing velocity in junior handball players. Twenty-six players were randomly assigned to an experimental (EG = 15, age 17.6 ± 0.51 years) and control (CG = 11, age 17.36 ± 0.50 years) group. Over an 8-week in-season period, the EG performed a ballistic training programme (2 sessions/week) immediately before their normal team handball training. Both groups underwent tests on the ASSSD, which operates in consecutive accelerative and decelerative actions, for throwing characteristics determination. Peak power (PP), peak force (PF), peak velocity (PV), peak rate of power development (PRPD), muscle volume (MV), throwing velocity with runup, standing throw, and jump throw were also assessed before/after the training programme. The EG group showed significant post-training improvements in PP (52.50% - p < 0.001), PF (26.45% - p < 0.01) and PRPD (78.47% - p < 0.001) better than the CG (1.81, 0.67 and 1.64%, p > 0.05, respectively). There was also a post-training improvement in the velocity at PP (22.82% - p < 0.001) and PF (42.45% - p < 0.001) in the EG compared to the CG (4.18 and 8.53%, p > 0.05 respectively). There was a significant increase in acceleration at PP (51.50% - p < 0.01) and PF (69.67% - p < 0.001). MV increased (19.11% - p < 0.001) in the EG, with no significant change (3.34% - p = 0.84) in the CG. Finally, significant increases were obtained in the three throw types (3.1-6.21%, p < 0.05- < 0.001) in the EG compared to the CG. The additional ASSSD training protocol was able to improve muscle strength/volume and ball throwing velocity in junior handball players.

Relationship between Swimming Performance, Biomechanical Variables and the Calculated Predicted 1-RM Push-up in Competitive Swimmers.

One repetition maximum (1RM) push-ups, based upon the load-velocity relationship, are able to predict the maximum upper body strength. The aim of the present study was to examine the relationship between the predicted 1RM push-up based upon the load-velocity relationship and swimming performance and kinematical variables in competitive swimmers. Thirty-three competitive male swimmers (age = 16.46 ± 0.59 years, body mass = 72.82 ± 8.41 kg, body height = 180.56 ± 5.69 cm) performed push-up exercises without a weight vest and with a 10, 20 and 30 kg weight vests. A load-velocity relationship was established as a product of the load and velocity of the push-up per participant, and the equation was used to establish a predicted 1RM. Our findings showed a predicted 1RM push-up of 82.98 ± 9.95 kg. Pearson correlations revealed a nearly perfect relationship between the 1RM push-up and the 25 or 50 m front crawl (r = -0.968, r = -0.955), and between 1RM push-up and the 25 or 50 m front crawl with arms (r = -0.955, r = x0.941). Similarly, our results revealed significant near-perfect correlations between 1RM push-up and kinematical variables (r = 0.93-0.96) except the stroke index, which had a large relationship (r = 0.56). This study suggests that swimming performance and kinematical variables are correlated with the predicted 1RM push-up. The 1RM push-up based upon the load-velocity relationship is a low cost and time-effective alternative for swimmers and coaches to predict maximum upper body strength to optimize swimming performance in short races.

What Is the Optimal Strength Training Load to Improve Swimming Performance? A Randomized Trial of Male Competitive Swimmers.

This study aimed to compare the effectiveness of high, moderate, and low resistance training volume-load of maximum strength training on muscle strength and swimming performance in competitive swimmers. Thirty-three male swimmers were randomly allocated to high (age = 16.5 ± 0.30 years), moderate (age = 16.1 ± 0.32 years) and a low resistance training volume-load group (age = 15.9 ± 0.31). This study was carried out in mid-season (January to March). Pre and post strength (e.g., repetition maximum [1RM] leg extension and bench press tests), swimming (25, 50 m front-crawl), start (speed, time, distance) and turn (time of turn) performance tests were conducted. Our findings revealed a large main effect of time for 1RM bench press: d = 1.38; 1RM leg extension: d = 1.55, and for 25 (d = 1.12), and 50 m (d = 1.97) front-crawl, similarly for start and turn performance (d = 1.28-1.46). However, no significant Group × Time interactions were shown in all strength swimming performances, start and turn tests (p > 0.05). In conclusion, low training loads have been shown to elicit the same results as moderate, and high training loads protocol. Therefore, this study shows evidence that the addition of low training volume-loads as a regular part of a maximal strength training regime will elicit improvements in strength and swimming performance.

Basketball-Specific Small-Sided Games Training during Ramadan Intermitting Fasting: Do Changes in Body Composition, Sleep Habits, and Perceived Exertion Affect Technical Performance?

The objective of this study was to assess the effects of an additional small-sided games (SSGs) training program during Ramadan intermitting fasting (RIF) on technical performance depending on changes in body composition, sleep habits, and ratings of perceived exertion (RPE). Twenty-four professional male basketball players from the Tunisian first division participated in this study. The players were randomly assigned to an intervention group (INT; n = 12) or an active control group (CON; n = 12). Both groups completed a four-week SSG training program (three sessions per week). During the first and fourth weeks of the SSGs training, the two groups were evaluated to detect changes in technical performance, dietary intake, body composition, sleep quality index (PSQI) survey outcomes, RPE, heart rate (HR), and blood lactate concentration [La]. During the fourth week of the RIF period, body composition, dietary intake, sleep latency, sleep duration, and HR significantly decreased only for INT (p < 0.001). However, RPE significantly increased (p < 0.001), and technical performances were negatively affected (p < 0.01). MANCOVA (adjusted for the percentage of change in sleep duration, body mass, and RPE) showed no significant differences in either group. In conclusion, our results showed that the technical performance of professional basketball male players was significantly affected at the end of RIF independently of changes in RPE, sleep habits, and body composition.

The Effect of Concurrent Resistance Training on Upper Body Strength, Sprint Swimming Performance and Kinematics in Competitive Adolescent Swimmers. A Randomized Controlled Trial.

This study aimed to examine the effect of 9 weeks of concurrent resistance training (CRT) between resistance on dry land (bench press (BP) and medicine ball throw) and resistance in water (water parachute and hand paddles) on muscle strength, sprint swimming performance and kinematic variables compared by the usual training (standard in-water training). Twenty-two male competitive swimmers participated in this study and were randomly allocated to two groups. The CRT group (CRTG, age = 16.5 ± 0.30 years) performed a CRT program, and the control group (CG, age = 16.1 ± 0.32 years) completed their usual training. The independent variables were measured pre- and post-intervention. The findings showed that the one-repetition maximum bench press (1RM BP) was improved only after a CRT program (d = 2.18; +12.11 ± 1.79%). Moreover, all sprint swimming performances were optimized in the CRT group (d = 1.3 to 2.61; -4.22 ± 0.18% to -7.13 ± 0.23%). In addition, the findings revealed an increase in velocity and stroke rate (d = 1.67, d = 2.24; 9.36 ± 2.55%, 13.51 ± 4.22%, respectively) after the CRT program. The CRT program improved the muscle strength, which, in turn, improved the stroke rate, with no change in the stroke length. Then, the improved stroke rate increased the swimming velocity. Ultimately, a faster velocity leads to better swim performances.

Dynamic Warm-Up With a Weighted Vest: Improvement of Repeated Change-of-Direction Performance in Young Male Soccer Players.

PURPOSE: To explore the effect of 4 different warm-up strategies using weighted vests and to determine the specific optimal recovery duration required to optimize the repeated change-of-direction (RCOD) performance in young soccer players. METHODS: A total of 19 male soccer players (age 18 [0.88] y, body mass 69.85 [7.68] kg, body height 1.75 [0.07] m, body mass index 22.87 [2.23] kg·m-2, and body fat percentage 12.53% [2.59%]) completed the following loaded warm-up protocols in a randomized, counterbalanced cross-over, within-participants order and on separate days: weighted vest with a loading of 5% (WUV5%), 10% (WUV10%), 15% (WUV15%) body mass, and an unloaded condition (control). RCOD performance (total time, peak time, and fatigue index) was collected during the preintervention phase (5 min after the dynamic stretching sequence) for baseline values and immediately (at 15 min), at 4- and 8-minute postwarm-up intervention. RESULTS: For each postwarm-up tested, recovery times (ie, 15 s, 4 min, and 8 min), of both total and peak times were faster following WUV5%, WUV10%, and WUV15%, compared with the unloaded condition (P ≤.001-.031, d = 1.28-2.31 [large]). There were no significant differences (P = .09-1.00, d = 0.03-0.72 [trivial-moderate]) in-between recovery times in both total and peak times following WUV5%, WUV10%, and WUV15%. However, baseline fatigue index score was significantly worse than all other scores (P ≤.001-.002, d = 1.35-2.46 [large]) following the loaded conditions. CONCLUSIONS: The findings demonstrated that a dynamic loaded warm-up increases an athlete's initial RCOD performance up to the 8-minute postwarm-up intervention. Therefore, strength coaches need to consider using weighted vests during the warm-up for trained athletes in order to acutely optimize RCODs.

Effects of flexibility combined with plyometric exercises vs isolated plyometric or flexibility mode in adolescent male hurdlers.

BACKGROUND: This study aims to determine the effect of flexibility exercises combined with plyometrics in hurdles race, on physical fitness, motor skills (MS) and hip range of motion. METHODS: Thirty-four male hurdlers, (age=15.7±0.7 years, body mass=59.7±2.3 kg, height=170.8±2.4 cm) were randomly assigned to four independent groups. The (Gflex+plyo), the (Gplyo), the (Gflex) and a control group (Gcon). All participants performed different tests: a test of right and left hip flexion (RHF, LHF) and extension (RHE, LHE), squat jump (SJ), countermovement jump (CMJ), stiffness jump (STFJ) and three (MS) exercises (running, hopping and leaping). A 60-m sprint on the hurdles was also performed. RESULTS: The two-way analyses of covariance for repeated measures showed that Gflex+plyo increased significantly: the CMJ, performance on 60-m and showed higher performance in the between groups' comparison. The Gflex+plyo and Gflex showed the higher percentages of changes in flexibility (RHF: 3.2±1.3% and 3.0±2.1%; RHE: 6.4±2.4% and 9.4±4.1%, LHE: 8.4±3.4% and 7.8±4.3%, respectively). Gplyo increased significantly the LHF (3.9±1.4%) more than the other groups. In the between groups' comparison, Gplyo showed the higher percentage of change in STFJ (6.4±1.8%) and the Gflex+plyo showed the higher values in running and hopping (10.7±4.6% and 13.3±2.1%, respectively). CONCLUSIONS: Specific stretching exercises combined with plyometrics may be more beneficial than other training strategies in young sprint-hurdlers. This may better improve physical fitness, hip range of motion and may increase different level of skills which may better improve performance in hurdles race.

Warm-Up With Dynamic Stretching: Positive Effects on Match-Measured Change of Direction Performance in Young Elite Volleyball Players.

PURPOSE: To explore the immediate (15-s post-warm-up) and the delayed (after 20 and 40 min of simulated volleyball play) effects of 2 different warm-up protocols-a stretching-free volleyball warm-up (NS) and a warm-up incorporating dynamic stretching (DS)-on subsequent change of direction (COD) performance in young elite volleyball players. METHODS: Sixteen male players (age 16.88 [0.34] y, body mass 75.81 [5.41] kg, body height 1.91 [0.05] m, body mass index 20.84 [1.79] kg·m-2, and body fat percentage 9.48 [1.83]%) from the U-17 national volleyball team performed NS and DS on 2 different nonconsecutive days. During each testing session (NS and DS), half T-test performance measurements were performed after 5 minutes of a general warm-up (ie, baseline), immediately post-warm-up (after 15 s), and after 20 and 40 minutes of simulated volleyball play. RESULTS: For DS, a significant improvement in COD performance (2.08%, P < .001) was observed after 20 minutes of play compared with the baseline values. In addition, COD performance recorded after 40 minutes of play was better than after 15-second post-warm-up (5.85%, P = .001). Inferential statistics showed better COD performance in the DS condition after 20 minutes of play (2.32%, likely negative, d = 0.61). CONCLUSIONS: Compared with NS, DS tended to affect the pattern of improvement of COD performance during play by intensifying and accelerating it. Consequently, to enhance COD performance for up to 40 minutes into the game, it is recommended that DS be incorporated to the warm-up preceding the match.

Auditory cues behind congenitally blind subjects improve their balance control in bipedal upright posture.

BACKGROUND: Congenitally blind subjects developed postural adaptations improving somatosensory and vestibular systems to maintain upright stability and auditory skills to orient them in environment. However, the influence of auditory cues on upright stability in congenitally blind subjects stays unknown. RESEARCH QUESTION: The aim of this study is to define the influence of an auditory cue in congenitally blind subjects back space on their balance posture. METHODS: Eleven sighted subjects and eleven congenitally blind subjects performed upright bipedal and unipedal quiet stances on a force plate with two conditions of auditory cue played by a loudspeaker placed 2 m behind them. Mean CoP velocity were recorded. Student test was used to compare significant difference between blind and sighted subjects bipedal and unipedal postures stability in both conditions of auditory cue. RESULTS AND SIGNIFICANCE: Results showed that congenitally blind subjects had no significant difference in mean sway velocity compared to sighted subjects in bipedal upright posture in auditory signal condition. However, blind subjects had significant lower mean sway velocity than sighted subjects in bipedal upright posture without sound. Blind subjects had significant increased mean sway velocity during unipedal quiet standing in both auditory cue conditions (with and without sound). The results showed that congenitally blind subjects used auditory cues placed behind them in order to improve their balance control in bipedal upright posture. In this case, blind subjects could better use compensatory mechanisms to perform quiet standing as sighted subjects. Without sound or in unipedal upright posture, congenitally blind subjects probably have sensory perturbations or limitations that impose them adaptations in order to avoid falling risk. Auditory cues should be study in the aim to better understand the compensatory mechanisms used by congenitally blind subjects to perform postural balance in usual environment.

Relationships Between Olympic Weightlifting Exercises, Peak Power of the Upper and Lower Limb, Muscle Volume and Throwing Ball Velocity in Elite Male Handball Players.

BACKGROUND: This study aimed to investigate relationships between peak power (PP) as measured by upper limb (PPUL) and lower limb (PPLL) force velocity tests, maximal upper limb force assessed by clean and jerk (1RMCJ) and snatch (1RMSE) exercises, estimates of local muscle volume and throwing ball velocity. METHODS: Thirty elite male handball players volunteered for the investigation (age: 20.3 ±â€Š2.1 years; body mass: 82.5 ±â€Š10.5 kg; height: 1.85 ±â€Š0,07 %; body fat: 13.1 ±â€Š2.1 %). Lower and upper limb force velocity tests were performed on appropriately modified forms of a Monark cycle ergometer with measurement of PPUL and PPLL, and the corresponding respective maximal forces (F0UL and F0LL) and velocities (V0UL and V0LL). Snatched (SN) and clean and jerk (CJ) exercises were performed to one repetition maximum (1RM). Handball throwing velocity was measured with jump shot (JS) without run-up (TW) and 3 steps shot (T3 step). Muscle volumes of the upper and lower limbs were estimated with a standard anthropometric kit. RESULTS: The 1RM CJ proved to be the most important predictor for throwing velocity. All types of throwing showed a high correlation with this parameter (JS: r = 0.75; TW: r = 0.62; T3 step: r = 0.66). The highest relation was detected between jump shot and 1RM snatch technique (r = 0.82). The PPUL muscle volume correlated highly with PPUL absolute power (r = 0.70). In contrast, we did not find any comparable relations for the lower limb (muscle volume vs. PPUL absolute power: r = 0.07). CONCLUSIONS: Our results highlight the contribution of both lower and upper limbs to handball throwing velocity, suggesting the need for coaches to include upper and lower limb strength weightlifting exercises and power programs when improving the throwing velocity of handball players.

Time-restricted feeding influences immune responses without compromising muscle performance in older men.

OBJECTIVE: This study examined the effect of 12 wk of time-restricted feeding (TRF) on complete blood cell counts, natural killer cells, and muscle performance in 20- and 50-year-old men. METHODS: Forty active and healthy participants were randomly divided into young experimental, young control, aged experimental, and aged control group. Experimental groups participated in TRF. Before (P1) and after (P2) TRF, participants performed a maximal exercise test to quantify muscle power. Resting venous blood samples were collected for blood count calculation. RESULTS: No changes were identified in muscle power in all groups after TRF (P > 0.05). At P1, red cells, hemoglobin, and hematocrit were significantly higher in young participants compared with elderly participants (P < 0.05). At P2, this age effect was not found in red cells between the young experimental group and the aged experimental group (P > 0.05). At P1, white blood cells and neutrophils were significantly higher in young participants compared with elderly participants (P < 0.05). At P2, only neutrophils decreased significantly (P < 0.05) in experimental groups without significant (P > 0.05) difference among them. Lymphocytes decreased significantly in the aged experimental group at P2 (P < 0.05), whereas NKCD16+ and NKCD56+ decreased significantly in experimental groups at P2 (P < 0.05). TRF had no effect on CD3, CD4+, and CD8+ levels (P > 0.05). CONCLUSION: TRF decreases hematocrit, total white blood cells, lymphocytes, and neutrophils in young and older men. TRF may be effective in preventing inflammation by decreasing natural killer cells. As such, TRF could be a lifestyle strategy to reduce systemic low-grade inflammation and age-related chronic diseases linked to immunosenescence, without compromising physical performance.

Relationships between the yo-yo intermittent recovery test and anaerobic performance tests in adolescent handball players.

The aim of the present study was to investigate relationships between a performance index derived from the Yo-Yo Intermittent Recovery Test level 1 (Yo-Yo IR1) and other measures of physical performance and skill in handball players. The other measures considered included peak muscular power of the lower limbs (Wpeak), jumping ability (squat and counter-movement jumps (SJ, CMJ), a handball skill test and the average sprinting velocities over the first step (VS) and the first 5 m (V5m). Test scores for 25 male national-level adolescent players (age: 17.2 ± 0.7 years) averaged 4.83 ± 0.34 m·s(-1) (maximal velocity reached at the Yo-Yo IR1); 917 ± 105 Watt, 12.7 ± 3 W·kg(-1) (Wpeak); 3.41 ± 0.5 m·s(-1) and 6.03 ± 0.6 m·s(-1) (sprint velocities for Vs and V5m respectively) and 10.3 ± 1 s (handball skill test). Yo-Yo IR1 test scores showed statistically significant correlations with all of the variables examined: Wpeak (W and W·kg(-1)) r = 0.80 and 0.65, respectively, p≤0.001); sprinting velocities (r = 0.73 and 0.71 for VS and V5m respectively; p≤0.001); jumping performance (SJ: r = 0.60, p≤0.001; CMJ: r= 0.66, p≤0.001) and the handball skill test (r = 0.71; p≤0.001). We concluded that the Yo-Yo test score showed a sufficient correlation with other potential means of assessing handball players, and that intra-individual changes of Yo-Yo IR1 score could provide a useful composite index of the response to training or rehabilitation, although correlations lack sufficient precision to help in players' selection.

Match analysis of elite adolescent team handball players.

The purposes of this study were to examine the activity profile of elite adolescent players during regular team handball games and to compare the physical and motor performance of players between the first and second halves of a match. Activity patterns (video analysis) and heart-rate (HR) responses (telemetry) were monitored in top national-division adolescent players (18 men, aged 15.1 ± 0.6 years) throughout 6 regulation games (25-minute halves with a 10-minute interval). The total distance covered averaged 1,777 ± 264 m per game (7.4% less in the second than in the first half, p > 0.05). Players ran 170 ± 24 m at high intensity and 86 ± 12 m at maximal speed, with 32 ± 6 bouts of running (duration 2.3 ± 0.3 seconds) at speeds > 18 km·h(-1); they stood still for 16% of the playing time. The mean HR during play was 172 ± 2 b·min(-1) (82 ± 3% of maximal HR). Blood lactate concentrations at the end of the first and second halves were 9.7 ± 1.1 and 8.3 ± 0.9 mmol·L(-1), respectively (difference p < 0.05). We conclude that adolescent handball players cover less distance and engage in fewer technical actions in the second half of a match. This indicates that team handball is physiologically very demanding. The practical implication is that coaches should seek to sustain performance in the second period of a game by modifying playing tactics and maximizing both aerobic and anaerobic fitness during training sessions.