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Context: Knowing the possible association between the isometric strength of the shoulder rotators, scapular muscles, and the Y-balance test upper quarter (YBT-UQ) performance could help identify which indicators of shoulder stability should be considered in this field test. This study aimed to determine whether the isometric strength of the shoulder rotators and scapular muscles is associated with the YBT-UQ performance of the dominant upper limb in amateur volleyball players. Design: Cross-sectional study. Methods: A convenience sample of 22 male and 18 female volleyball players (≥12 h of training/week) between 18 and 26 years of age. The isometric strength of the middle trapezius, lower trapezius, serratus anterior, internal, and external rotator muscles was assessed with a handheld dynamometer. Participants performed the YBT-UQ in the superolateral, medial, and inferolateral directions. The absolute isometric peak force (in Newtons) was normalized to body weight (in Newtons per kilogram) for each muscle test. For each YBT-UQ direction, the distance (in centimeters) was normalized for upper limb length (in percentage). A backward multiple linear regression analysis was used to determine the associations between variables. Results: The analysis revealed that the isometric strength of the lower trapezius (β = 26.82; 95% confidence interval, 21.24–32.40) is associated with inferolateral YBT-UQ performance (adjusted R2 = .706; P Conclusions: Lower trapezius isometric strength is associated with inferolateral YBT-UQ performance of the dominant upper limb in amateur volleyball players. These findings could help in the development of more specific training programs and rehabilitation goals according to the performance of the athletes in the test.

This study examined the effects of body mass-based resistance training (bmRT) on selected measures of physical fitness and injury incidence and burden in soccer players. Forty-six U16 male soccer players were randomly assigned to an control (CG; n = 26) or experimental group (EG; n = 20) Countermovement jump (CMJ), change of direction (CoD) (i.e., 20 m with one CoD), and linear sprint over 30 m were assessed before and after a 15-weeks training. Any type of musculotendinous injury that occurred throughout the intervention period was recorded. Between-group difference was noted at post-test for CMJ (p = 0.008). Pre-to-post training values increased in the EG (effect size [ES] = 1.01) while in the CG no pre-to-post changes were detected (ES = 0.27). No between-group differences at post-test were observed for sprint and CoD tests. Differences in injury burden were reported (33.28 [CG] vs. 9.55 [EG] absence days/1,000 hours exposure, rate ratio = 3.49, 95% CI 2.03-6.00, p

This study aimed to contrast the effects of power training (PT) and plyometric-jump-training (PJT) programmes on measures of physical fitness in prepubertal male soccer players. Thirty-three participants were randomly allocated to PT group (n = 11), PJT group (n = 11), and an active control group (CG; n = 11). Before and after 12 weeks of training, tests were performed for the assessment of sprint-speed , change-of-direction (CoD) speed, muscular strength , and aerobic-endurance (AE). Findings indicated significant group×time interaction effects for all sprint-speed intervals, CoD speed, AE, and strength (

Purpose: To examine the effects of balance exercises conducted prior to complex training (bCT) versus complex training (CT) only on measures of physical fitness in young female elite handball players. Methods: Participants aged 17 years were randomly assigned to bCT (n = 11) or CT (n = 12). The 2 training interventions lasted 8 weeks with 2 sessions per week in replacement of some technical/tactical handball exercises and were matched for total training volume. Before and after training, tests were performed for the evaluation of proxies of muscle power (countermovement jump height, standing long-jump distance, and reactive strength index), muscle strength (back half-squat 1-repetition maximum), dynamic balance (Y-balance test), linear sprint speed (20-m sprint test), and change-of-direction speed (T test). Results: Two-factor repeated-measures analysis of variance revealed significant group × time interactions for the reactive strength index (d = 0.99, P = .03) and Y-balance test score (d = 1.32, P d = 0.69, P = .04) only. For the Y-balance test, significant pre–post increases were found in bCT (d = 0.71, P = .04) with no significant changes in CT (d = 0.61, P = .07). In addition, significant main effects of time were observed for half-squat 1-repetition maximum, countermovement jump, standing long jump, and T test performance (d = 1.50 to 3.10, P Conclusions: Both bCT and CT interventions were effective in improving specific measures of physical fitness in young elite female handball players. If the training goal is to improve balance in addition, balance exercises can be conducted within a CT training session and prior to CT exercises.

This research was supported by the Pre-competitive Projects for Early Stage Researchers Programme from the University of Granada (ref: PPJIA2020.03), 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., Pre-competitive Projects for Early Stage Researchers Programme from the University of Granada PPJIA2020.03

Background: In spite of there are a wide knowledge of the prevalence of hypertension in adult, there is poor information on schoolchildren of different ethnicity and gender. Aim: To compare the levels of blood pressure and other cardiometabolic risk factors for hypertension between schoolchildren of different gender and ethnicity. Material and methods: In a cross-sectional study, 540 schoolchildren (6-13 years) ascendants from a Chilean public school population were analysed by ethnicity and gender in four groups (Mapuches N = 55; European boys N = 199, and Mapuches N = 64, and European girls N = 222). The study included the measurement of cardiovascular (systolic and diastolic blood pressure) as main outcomes, as well as other cardiovascular (resting heart rate), body composition (body mass, BMI, waist circumference, fat mass, muscle mass), muscle strength (handgrip strength of dominant, non-dominant, and mean handgrip strength) as additional cardiometabolic outcomes. Results: The systolic blood pressure was significantly higher in Mapuches girls 126 +/- 4 vs. their European counterparts 119 +/- 3 mmHg, P < .002, as well as diastolic blood pressure, was higher in Mapuches girls 82 +/- 5 vs. European girls 74 +/- 3 mmHg, P < .0001. There were more 'prehypertensive' Mapuches girls 10 (15.6%) vs. European peers 22 (9.9%) at P < .0001, and the 'hypertension' was significantly more prevalent in Mapuches boys 19 (34.5%) vs. European peers 39 (19.4%) at P < .0001, as well as in Mapuches girls 16 (25%) vs. European peers 33 (14.9%) at P < .0001. The 'obesity' was less prevalent in Mapuches 10 (18.2%) vs. European boys 55 (27.4%) at P < .0001. The waist circumference was high in European 74 +/- 4 vs. Mapuches 67 +/- 6 cm, P < .012 in boys, although, waist circumference was high in Mapuches girls 75 +/- 5 vs. European peers 71 +/- 3 cm, P < .021. There were higher levels of muscle mass in Mapuches boys 19.5 +/- 12 vs. European peers 17.1 +/- 4 kg, P < .0001. Conclusion: Mapuches girls show higher levels of systolic and diastolic BP than European girls, Mapuches boys and girls are more hypertensive than European peers, but are less obese than European schoolchildren peers. These cardiometabolic differences that are more detrimental for endemic ethnic Latinoamerican groups are in need to be explored further.

Castillo, D, Rodríguez-Fernández, A, Nakamura, FY, Sanchez-Sanchez, J, Ramirez-Campillo, R, Yanci, J, Zubillaga, A, and Raya-González, J. Influence of different small-sided game formats on physical and physiological demands and physical performance in young soccer players. J Strength Cond Res 35(8): 2287-2293, 2021-The aim of this study was to quantify the acute impact of bout duration and individual interaction space on physical and physiological demands and on physical performance. Ten young male soccer players (age: 14.8 ± 0.6 years) from the same team playing in the National U-16 Division participated. Physical (total distance [TD]; distance covered at different speeds; and maximum velocity [Velmax]) and physiological (peak [HRpeak] and mean [HRmean] heart rate) parameters were collected for every bout during each small-sided game (SSG) format. Moreover, the effects of SSGs on horizontal jump (HJ) and 30-m sprint performances were evaluated. The SSG formats were composed of 6 players a side (including goalkeepers) and included 4 repetitions of 6 minutes in a space of 100 m2 (SSG1) or 200 m2 (SSG2) and 6 repetitions of 4 minutes in 100 m2 (SSG3) or 200 m2 (SSG4). The TD, the distance covered at different speeds, and Velmax were greater (p0.01, effect size [ES] = 1.25-5.95, large) in SSG2 and SSG4 than SSG1 and SSG3, respectively. Furthermore, the HRmean and HRpeak were lower (p0.05, ES = 1.53-2.23, large) during SSG3 than other SSGs. In addition, while a significant (p0.05, ES = 0.70-2.04, moderate to large) increase in SPR30 time in SSG1 and SSG3 was observed, HJ performance was not affected (p0.05, ES = 0.03-0.54, trivial to moderate) by any SSG format. These findings suggest increasing pitch size to induce greater physical demands and to use SSGs with smaller pitch size, and independently of the bout duration, to induce neuromuscular fatigue.

Our purpose in this review was to determine the effects of bodyweight-only neuromuscular training (NMT) programs on motor control of movement among youth athletes. We searched three electronic databases (CrossRef, Google Scholar, and PubMed), using the following inclusion criteria for selecting research studies: (a) healthy male and female participants aged 8-18 years who were engaged in organized sports; (b) interventions up to 16-weeks duration; (c) incorporation of a control group; and (d) interventions that utilized only exercises using participants’ body mass. We calculated pooled estimates of effect sizes (standardized mean difference) for changes in motor control across nine studies (12 comparisons) using the inverse-variance random effects model for meta-analyses and 95% confidence intervals. Among the nine studies included in our meta-analysis, there was a moderate, significant effect in favor of neuromuscular training programs (0.79 [95% CI: 0.38, 1.20], Z = 3.76 [ p = 0.0002]) on motor control. Heterogeneity was high and significant ( I2= 77% [ p = 0.00001]). Moderator analyses for age and stature revealed NMT programs to be more effective in younger, shorter, and lighter individuals. We found larger effect sizes in males, and for programs >8 weeks in duration. We concluded that the older and heavier an individual is, the less effective bodyweight-only NMT programs became, particularly for female participants. These results reinforce the notion that exercise to enhance motor control should be emphasized during pre-adolescence.

To assess the effects of a specific injury prevention neuromuscular training programme (IPP) on balance and lower-limb asymmetry in female competitive dancers (age 12-20 years; height 1.57 ± 0.06 m; weight 24.27 ± 2.79 kg) were randomly allocated to an active general control (GIPP, n = 7) and specific (SIPP n = 7) group. Both programmes were conducted for 6 weeks, with a frequency of three sessions per week. Dynamic balance and lower-limb asymmetry were assessed before and after the intervention. A greater improvement in right-leg total balance (86.6[84.0-90.5] vs 93.8[86.7-99.4];p = 0.035), left-leg total balance(87.8[81.0-89.1] vs 93.6[90.6-100.0];p = 0.013), left-leg anterior balance (71.9[69.1-72.2] vs 74.6[72.0-77.3];p = 0.041), left-leg posteromedial balance (80.5[72.9-83.3] vs 85.9[83.0-94.0];p = 0.048), and left-leg posterolateral balance (79.5[70.4-84.5] vs 85.0[80.0-88.5];p = 0.048) was observed in the SIPP group compared to the GIPP group. No other significant intra-group changes nor inter-group differences were noted. Therefore, compared to a GIPP, a SIPP induced greater improvements in lower-limb dynamic balance in female dancers, potentially leading to greater reduction in lower-limb injury risk.

This controlled study investigated the effects of 7 weeks pre-season supplemental jump and sprint exercise training on sand (JSETS) on athletic ability in male handball players. Males (n = 40; 16.3 ± 0.4 years) were randomly assigned to a jump and sprint training (JSTG; n = 24) or a control (CG; n = 18) group. The JSETS replaced a part of the regular handball training of players. The tests included jumps (squat, counter-movement, and 5 jump tests), sprint times (5 m, 10 m and 20 m), agility (modified T and modified Illinois tests), repeated sprint T-test, and balance (standing stork and Y balance tests). JSTG showed relative to CG significant decreases in sprint times over all distances (5 m (p = 0.002, d = 0.735 (medium); 10 m (p = 0.012, d = 0.577 (medium) and 20 m (p = 0.012, d = 0.573 (medium)), and gains in both measures of agility (p = 0.001, d = 0.859 (large) and p = 0.004, d = 0.670 (medium) for T-Half and Illinois-tests respectively), and in jumping squat (p

This systematic review and meta-analysis aimed to assess the effects of jump training (JT) on measures of physical fitness and athletic performances in endurance runners. Controlled studies which i...

There is a growing body of research examining the effects of plyometric jump training (PJT) on repeated sprint ability (RSA) in athletes. However, available studies produced conflicting findings and the literature has not yet been systematically reviewed. Therefore, the effects of PJT on RSA indices remain unclear. To explore the effects of PJT on RSA in athletes. Searches for this review were conducted in four databases. We included studies that satisfied the following criteria: (1) examined the effects of a PJT exercise intervention on measures of RSA; (2) included athletes as study participants, with no restriction for sport practiced, age or sex; and (3) included a control group. The random-effects model was used for the meta-analyses. The methodological quality of the included studies was assessed using the PEDro checklist. From 6367 search records initially identified, 13 studies with a total of 16 training groups (n = 198) and 13 control groups (n = 158) were eligible for meta-analysis. There was a significant effect of PJT on RSA best sprint (ES = 0.75; p = 0.002) and RSA mean sprint (ES = 0.36; p = 0.045) performance. We did not find a significant difference between control and PJT for RSA fatigue resistance (ES = 0.16; p = 0.401). The included studies were classified as being of “moderate” or “high” methodological quality. Among the 13 included studies, none reported injury or any other adverse events. PJT improves RSA best and mean performance in athletes, while there were no significant differences between control and PJT for RSA fatigue resistance. Improvements in RSA in response to PJT are likely due to neuro-mechanical factors (e.g., strength, muscle activation and coordination) that affect actual sprint performance rather than the ability to recover between sprinting efforts.

This systematic review with meta-analysis (SRMA) was conducted to assess the effects of high-intensity interval training (HIIT) programmes on men soccer players' aerobic fitness (maximal oxygen uptake and aerobic performance), repeated sprint ability (RSA), vertical jump height (VJH), and linear sprinting time (ST). An electronic search yielded 1,714 articles, 33 of which were included in the present study. Meta-analyses revealed significant benefits of HIIT compared to controls in maximal oxygen uptake (p = 0.018), AP (p = 0.041), and RSA (p = 0.049). No significant effects were found in terms of ST (p = 0.080). The meta-analyses of non-controlled studies revealed significant improvements after HIIT in maximal oxygen uptake (p = 0.001), AP (p = 0.007), RSA (p = 0.001), and ST (p0.001). However, no significant improvements in VHJ were found (p = 0.063). Furthermore, no significant differences were found in sub-group analysis (comparisons between HIIT types). In conclusion, HIIT is effective for improving maximal oxygen uptake, AP, and RSA regardless of the HIIT type. For VHJ and ST outcomes, it seems reasonable to complement the HIIT since it might not be enough to achieve significant changes.

Context The Nordic hamstring exercise (NHE) is known to reduce hamstrings injury risk in athletes. To optimize the NHE, it is important to understand how acute resistance-training variables influence its performance. Objective To examine the effects of different interset rest intervals (ISRIs) on force indices during performance of the NHE. Design Crossover study. Setting Laboratory. Patients or Other Participants Ten well-trained, young, male, team-sport athletes (age = 20.7 ± 2.3 years, height = 179.4 ± 5.5 cm, mass = 83.9 ± 12.4 kg). Intervention(s) Participants performed 2 sets of 6 repetitions of the NHE with either a 1- or 3-minute ISRI. All sets were performed using the NordBord. Main Outcomes Measure(s) Peak force (newtons), average force (newtons), percentage maintenance, and percentage decline were recorded for both the dominant and nondominant limbs, and interlimb force asymmetries (percentages) were calculated. Results No interactions or main effects (P > .05) were present between conditions or sets for any variables. However, individual repetitions showed reductions (P< .05; effect size range = 0.58–1.28) in peak force from repetition 4 onward. Conclusions Our findings suggest that a 1-minute ISRI was sufficient to maintain force-production qualities and interlimb asymmetries between sets during the NHE in well-trained athletes. Nonetheless, practitioners should be aware of the potentially large decrements in peak force production that may occur within the set.

The off-season period in soccer leads necessarily to changes in fitness status. However, there is a lack of systematization that allows identifying the magnitude of these changes in groups participating in off-season training programs compared with those subjected to training cessation. This systematic review with meta-analysis was conducted to assess the effects of training cessation in off-season training programs on men soccer players’ body fat, maximal oxygen uptake (VO2max), yo–yo intermittent recovery test (YYIRT), vertical jump, sprinting time, and repeated-sprint ability. To qualify for inclusion in the systematic review, studies must have included: (1) a detraining period of ≥ 2 weeks; (2) controlled trials or cohorts of healthy men soccer players with no restriction on age; and (3) a pre–post training cessation or off-season training programs measure of body fat (%), VO2max (mL kg−1 min−1), YYIRT performance (meters), vertical jump (height), sprinting (time), and repeated-sprint ability (total time). The electronic search yielded 563 articles, and 12 were subsequently included. Significant (all p

This systematic review and meta-analysis aimed to analyse the technologies and main training variables used in the literature to monitor flywheel training devices in real time. In addition, as the main research question, we investigated how eccentric overload can be effectively monitored in relation to the training variable, flywheel shaft type device and the moment of inertia selected. The initial search resulted in 11,621 articles that were filtered to twenty-eight and seventeen articles that met the inclusion criteria for the systematic review and meta-analysis, respectively. The main technologies used included force sensors and rotary/linear encoders, mainly to monitor peak or mean force, power or speed. An eccentric overload was not always achieved using flywheel devices. The eccentric overload measurement was related to the main outcome selected. While mean force (p = 0.011, ES = -0.84) and mean power (p < 0.001, ES = -0.30) favoured the concentric phase, peak power (p < 0.001, ES = 0.78) and peak speed (p < 0.001, ES = 0.37) favoured the eccentric phase. In addition, the lower moments of inertia (i.e., from 0.01 to 0.2 kg·m2) and a cylindrical shaft type (i.e., vs conical pulley) showed higher possibilities to achieve eccentric overload. A wide variety of technologies can be used to monitor flywheel devices, but to achieve eccentric overload, a flywheel cylindrical shaft type with low moments of inertia is advised to be used.

Andrade, DC, Manzo, O, Beltran, AR, Alvarez, C, Del Rio, R, Toledo, C, Moran, J, and Ramirez-Campillo, R. Kinematic and neuromuscular measures of intensity during plyometric jumps. J Strength Cond Res 34(12): 3395-3402, 2020-The aim of this study was to assess jumping performance and neuromuscular activity in lower limb muscles after drop jumps (DJs) from different drop heights (intensity) and during continuous jumping (fatigue), using markers such as reactive strength, jump height, mechanical power and surface electromyography (sEMG). The eccentric (EC) and concentric (CON) sEMG from the medial gastrocnemius (MG), biceps femoris (BF), and rectus (R) muscles were assessed during all tests. In a cross-sectional, randomized study, 11 volleyball players (age 24.4 ± 3.2 years) completed 20-90-cm (DJ20 to DJ90) DJs and a 60-second continuous jump test. A 1-way analysis of variance test was used for comparisons, with Sidak post hoc. The α level was

Both bilateral (BLE) and unilateral resistance exercise (ULE) methods can confer benefit to an athlete, but it remains to be established which has a greater effect on movement speed. To evaluate the effects of BLE and ULE on horizontal movement performance. Google Scholar, CrossRef, and PubMed. To qualify for inclusion in the meta-analysis, studies must have included a resistance training intervention that compared the effects of BLE and ULE on a measure of movement speed such as sprinting in healthy study participants. We used the inverse-variance random-effects model for meta-analyses. Effect sizes (standardised mean difference), calculated from measures of horizontally orientated performance, were represented by the standardised mean difference and presented alongside 95% confidence intervals (CI). Though both modalities were effective (BLE = 0.60 [95% CI 0.34, 0.87], Z = 4.44 [p

Vera-Assaoka, T, Ramirez-Campillo, R, Alvarez, C, Garcia-Pinillos, F, Moran, J, Gentil, P, and Behm, D. Effects of maturation on physical fitness adaptations to plyometric drop jump training in male youth soccer players. J Strength Cond Res 34(10): 2760-2768, 2020-The objective of this study was to compare the effects of maturation on physical fitness adaptations to a twice weekly, 7-week plyometric drop jump training program. Seventy-six young male soccer players (aged 10-16 years) participated in this randomized controlled trial. Before and after the intervention, a physical fitness test battery was applied (countermovement jump; drop jump from 20 to 40 cm; 5 multiple bounds test; 20-m sprint time; change of direction speed; 2.4-km running time-trial; 5 repetition maximum [RM] squat; and maximal kicking distance). Participants were randomly divided into an active soccer-control group (CG) with Tanner stage maturation of 1-3 (CG-early; n = 16) or Tanner stage 4-5 (CG-late; n = 22), and to plyometric drop jump training groups with Tanner stage 1-3 (plyometric jump training [PJT]-early; n = 16) or 4-5 (PJT-late; n = 22). The analysis of variance and effect size (ES) measures revealed that when compared with their age-matched controls, the PJT-early (ES = 0.39-1.58) and PJT-late (ES = 0.21-0.65) groups showed greater improvements (p < 0.05) in sprint time, 2.4-km running time-trial, change of direction speed, 5RM squat, jumping, and kicking distance. The PJT-early exceeded the PJT-late group with greater (p < 0.05) improvements in drop jump from 20 cm (ES = 1.58 vs. 0.51) and 40 cm (ES = 0.71 vs. 0.4) and kicking distance (ES = 0.95 vs. 0.65). Therefore, a 7-week plyometric drop jump training program was effective in improving physical fitness traits in both younger and older male youth soccer players, with greater jumping and kicking adaptations in the less-mature athletes.

In accordance with the principle of training specificity, adaptations to vertically or horizontally orientated plyometric training (VPT, HPT) directly transfer to athletic tasks that are carried out in the same direction as they are performed. The objective of this systematic review and meta-analysis was to determine the relative effect of VPT and HPT on both vertical and horizontal measures of physical performance. Google Scholar, CrossRef, Microsoft Academic, PubMed, Web of Science, Scopus. To qualify for inclusion in the meta-analysis, studies must have included a plyometric training intervention that compared jumps executed in a vertical direction [i.e. countermovement jump (CMJ)] to jumps executed in a horizontal direction (i.e. standing horizontal jump). We used the inverse-variance random effects model for meta-analyses. Effect sizes, calculated from measures of horizontally or vertically orientated performance, were represented by the standardised mean difference and presented alongside 95% confidence intervals (CI). For between-group analysis on horizontal outcomes, there was a moderate, significant effect size (ES) in favour of HPT (0.65 [95% CI 0.12, 1.18], Z = 2.41 [p = 0.02]). For the analysis on vertical outcomes, there was a trivial, non-significant difference between VPT and HPT (− 0.04 [95% CI − 0.33, 0.24], Z = 0.0.29 [p = 0.77]). Within-group analysis showed HPT to be superior to VPT across horizontally- (1.05 [0.38, 1.72] vs. 0.84 [0.37, 1.31]) and vertically-orientated (0.74 [0.08, 1.40] vs. 0.72 [0.02, 1.43]) performance measures. For horizontally-orientated outcomes, single-factor moderator analyses showed that longer programmes (> 7 weeks), more sessions (> 12) and combined bilateral and unilateral training were most effective, favouring HPT in each case. In vertically orientated outcomes, these same variables showed only trivial differences between HBT and VBT. HPT is at least as effective as VPT at enhancing vertical performance but is superior at enhancing horizontal performance. This means that HPT might be a more efficient method for enhancing multi-vector performance for sport.

Context: Plyometric training promotes a highly effective neuromuscular stimulus to improve running performance. Jumping rope (JR) involves mainly foot muscles and joints, due to the quick rebounds, and it might be considered a type of plyometric training for improving power and stiffness, some of the key factors for endurance-running performance. Purpose: To determine the effectiveness of JR during the warm-up routine of amateur endurance runners on jumping performance, reactivity, arch stiffness, and 3-km time-trial performance. Methods: Athletes were randomly assigned to an experimental (n = 51) or control (n = 45) group. Those from the control group were asked to maintain their training routines, while athletes from the experimental group had to modify their warm-up routines, including JR (2–4 sessions/wk, with a total time of 10–20 min/wk) for 10 weeks. Physical tests were performed before (pretest) and after (posttest) the intervention period and included jumping performance (countermovement-jump, squat-jump, and drop-jump tests), foot-arch stiffness, and 3-km time-trial performance. Reactive strength index (RSI) was calculated from a 30-cm drop jump. Results: The 2 × 2 analysis of variance showed significant pre–post differences in all dependent variables (P P ≥ .05). Pearson correlation analysis revealed a significant relationship between Δ3-km time trial and ΔRSI (r = −.481; P r = −.336; P R2 = .394; P Conclusions: Compared with a control warm-up routine prior to endurance-running training, 10 weeks (2–4 times/wk) of JR training, in place of 5 minutes of regular warm-up activities, was effective in improving 3-km time-trial performance, jumping ability, RSI, and arch stiffness in amateur endurance runners. Improvements in RSI and arch stiffness were associated with improvements in 3-km time-trial performance.

This study aimed to assess the effects of jump training on the jumping performance of handball players compared with a control condition. The data sources utilised were PubMed, MEDLINE, Web of Science Core Collection and SCOPUS. Only peer-review randomised controlled trials were included. The inclusion criteria comprised: a jump training programme of at least 2 weeks; a control group; the assessment of the countermovement jump. The Physiotherapy Evidence Database scale was used to assess the risk of bias and methodological quality of eligible studies included in the meta-analysis. Risk of publication bias across studies was assessed using the extended Egger’s test. Cohen’s d effect sizes (ESs) were calculated from the countermovement jump and presented together with 95% confidence intervals (CIs). From 6108 records initially identified through database searching, 5 were eligible for meta-analysis. A significant improvement in countermovement jump height was observed, corresponding to 6.4 cm (95% CI = 4.9–7.9; Z = 8.4, p 2 = 51.4%). The magnitude of the main effect was very large (ES = 2.2 (95% CI = 0.95–3.4), Z = 3.5, p

Bouguezzi, R, Chaabene, H, Negra, Y, Ramirez-Campillo, R, Jlalia, Z, Mkaouer, B, and Hachana, Y. Effects of different plyometric training frequencies on measures of athletic performance in prepuberal male soccer players. J Strength Cond Res 34(6): 1609-1617, 2020-This study aimed to compare the effects of 1 vs. 2 sessions of equal-weekly volume plyometric training (PT) across 8 weeks on measures of athletic performance (i.e., sprint time, change of direction [CoD], jumping ability, and muscle strength) in prepuberal male soccer players. Thirty participants were randomly assigned either to 1 session PT group (1SPT [n = 15]) or 2 sessions PT group (2SPT [n = 15]). Plyometric training was integrated into their regular soccer training routine. Pretraining and posttraining tests for the assessment of sprint time (e.g., 5, 10, 20, and 30-m), CoD (e.g., T-test and modified Illinois change of direction test [MICODT]), jumping ability (e.g., standing long jump [SLJ], countermovement jump [CMJ], and squat jump [SJ]), muscle strength (reactive strength index [RSI]), and kicking distance were conducted. Results showed a main effect of time for 5-m sprint-time performance (F(1,56) = 4.00, effect size [ES] = 0.53 [medium], p = 0.05), T-test (F(1,56) = 23.19, ES = 1.28 [large], p0.001), MICODT (F(1,56) = 5.72, ES = 0.94 [large], p = 0.02), SLJ (F(1,56) = 16.63, ES = 1.09 [large], p0.001), CMJ (F(1,56) = 15.43, ES = 1.04 [large], p0.001), SJ (F(1,56) = 20.27, ES = 1.20 [large], p0.001), RSI (F(1,56) = 26.26, ES = 1.36 [large], p0.001), and kicking distance (F(1,56) = 47.19, ES = 1.83 [large], p0.001). There were no training group × time interactions in all the measured outcomes. In conclusion, when an equated moderate volume of jumps is performed, higher PT frequency across 8 weeks has no extra effects on prepuberal male soccer players' measures of athletic performance. The present findings may help optimizing PT interventions dedicated to prepuberal male soccer players.

SUMMARY: Lower-limbs appendicular muscle mass is a key body composition trait related to health and performance. Considering the relevance of lower-limbs appendicular muscle mass in soccer players, the assessment and monitoring of this variable with a low-cost tool would be of great value in order to improve performance through training and nutritional interventions. This study aimed to develop a multiple regression model in order to validate, through dual-energy X-ray absorptiometry, a novel equation to predict lower-limbs appendicular muscle mass in young soccer players using anthropometric variables. Forty-two soccer players of the Chilean National Team (age, 17.1±1.3 years; body mass, 70.0±6.8 kg; height, 175.0±6.6 cm) underwent anthropometrically and body composition assessments. Forward stepwise linear regression was used to develop the equation to estimate the lower-limb appendicular muscle mass. The estimated results were compared with measurements by dual-energy X-ray absorptiometry. The best predictor model to estimate lower-limbs appendicular muscle mass was (kg): (-21.268 + (0.087*height) - (0.853*middle thigh circumference) - (0.329*middle thigh skinfold) + (1.136*corrected middle thigh circumference) + (0.306*calf circumference)) (R2= 0.83). The lower-limbs appendicular muscle mass estimated by the equation and measured by DXA were similar (14.71±1.72 kg vs 14.76±1.89 kg, respectively), and have a good concordance according to Bland-Altman method (mean difference: 0.049 kg; 95 % IC: -1.481 to 1.578 kg) and Lin’s concordance correlation coefficient (0.91; 95 % CI: 0.85 - 0.96) methods. In conclusion, the predictive equation is a valid, easy to calculate, and a low-cost tool to predict lower-limbs appendicular muscle mass in young soccer players.

Introduction: Judo is a high-intensity sport, characterized by a series of acyclic movements that require high technical mastery during combat. It was previously shown that growth of components of physical function is related with an increased probability successful competitive performance. Suspension training is effective at improving components of physical function. Objective: Therefore, the aim of this study was to determine the changes in physical performance traits of youth judokas after a 5-week suspension-training programme. Methods: Ten judokas (age, 15.4 ± 2.8 y) completed a 5-week suspension training routine into their normal training schedule. The difficulty and intensity of the exercises were increased each week. Before and after the intervention athletes were assessed in the single-leg horizontal jumping, Sorensen test, sit-and-reach, Y balance, prone instability and handgrip strength tests. Results: Significant improvements (p

Purpose: To examine the variations in the velocity of contraction (Vc) assessed using tensiomyography, vertical jumping ability, and sprinting speed induced by 4 different exercise protocols (ie, strength, sprint, plyometric, and technical training sessions) in 14 male national-team rugby players (age 21.8 [2.6] y, weight 83.6 [8.5] kg, and height 177.4 [6.7] cm). Methods: Physical tests were conducted immediately before and after 4 distinct workouts in the following order: tensiomyography in the rectus femoris and biceps femoris muscles, squat and countermovement jumps, and 30-m sprint velocity. To analyze the differences in the assessed variables before and after each training session, the differences based on magnitudes were calculated. Results: After strength and plyometric workouts, the players presented possible to almost certain impairments in sprint and jump performance and in the Vc of the rectus femoris (effect sizes 0.26–0.64). After the sprint-training session, possible to very likely decreases were observed in the squat jump, 30-m sprint, and Vc of the biceps femoris (effect sizes 0.21–0.44). By contrast, after the technical training, athletes demonstrated a possible increase in the squat jump and Vc in both muscles examined (effect sizes 0.13–0.20). Conclusions: The main finding of this research is that, for the vast majority of results, the direction of changes observed in Vc were the same as those observed in performance assessments. This suggests that Vc might be used as a sensitive marker of acute variations in speed and power performance of elite team-sport athletes.

Plyometric jump training (PJT) can be used for improving balance through bilateral and unilateral jump-landing drills. Since the increased number of articles testing the effects of PJT on dynamic and static balance, it is relevant to summarize the evidence and determine the effects across different original articles. This systematic review with meta-analysis was conducted to assess the effects of PJT programs on dynamic and static balance in soccer players. The data sources utilized were Cochrane, Medline (PubMed), SPORTDiscus, and Web of Science. (i) Soccer players of any age or sex without injury, illness, or other clinical conditions; (ii) PJT-based programs restricted to a minimum of three weeks (duration); (iii) passive or active control groups; (iv) pre-post interventions values of dynamic and/or static balance; (v) randomized-controlled trials; and (vi) peerreviewed original full-text studies written in English, Portuguese, and/or Spanish. The database search initially identified 803 titles. From those, eight articles were eligible for the systematic review and meta-analysis. The results showed no significant differences between PJT and active controls in dynamic anterior, postero-medial, or postero-lateral balance for both left and right legs (p0.05). Additionally, no significant differences were found between PJT and active controls in terms of static balance (p = 0.495). The current evidence suggests that PJT has no significant advantage over active control groups in terms of dynamic or static balance.

Made available in DSpace on 2022-04-28T19:50:17Z (GMT). No. of bitstreams: 0 Previous issue date: 2022-03-01 BACKGROUND: This study aimed to quantify internal training load and changes in vertical jumping ability and endurance capacity of professional volleyball players during the preseason, and to explore relationships between players' physical qualities at the beginning of the preseason with internal training load accumulated during the first two weeks of training. METHODS: Sixteen male professional volleyball players from a team participating in the Brazilian National Super League took part in the study. Before and after a 10-week preseason, their vertical jumping ability and endurance capacity were assessed by squat jump, countermovement jump without and with arm swing, and YoYo endurance test, level 1. The internal training load was quantified by the session rating of perceived exertion method. Results were analyzed using analysis of variance, magnitude-based inference and Pearson's correlation. RESULTS: The internal training load varied between 1388±111 arbitrary units (a.u.) and 3852±149 a.u., and performance in all the tests was positively changed (small to moderate effect sizes) at end of preseason training. Significant (P

Background: This study aims to assess the effects of 8 weeks of plyometric jump training (PJT) conducted on sand or a rigid court surface on jump-related biomechanical variables and physical fitness in female indoor volleyball players. Methods: Seventeen participants were randomly divided into a sand surface group (SsG, n = 8) and rigid surface group (RsG, n = 9). Both groups completed equal indoor volleyball training routines. Participants were assessed pre and post the 8-week PJT for jump-related biomechanical variables (countermovement jump (CMJ) RSI; drop jump (DJ) reactive strength index (RSI); spike jump (SJ) height; CMJ height; CMJ rate of force development (RFD); CMJ velocity at take-off; DJ height and CMJ peak force), 20 m linear sprint time, t test for change-of-direction sprint (CODs) time, Wingate test peak power (PP), cardiorespiratory endurance, and leg-press one-repetition maximum (1RM). Results: A two-way mixed analysis of variance (group × time) revealed that there was a significant group × time interaction between DJ height (p = 0.035) and CMJ peak force (p = 0.032) in favour of RsG and SsG, respectively. A significant interaction was also observed for cardiorespiratory endurance (p = 0.01) and 1RM (p = 0.002), both favouring the SsG. No other group × time interaction was observed. Conclusions: The type of surface used during PJT induced specific adaptations in terms of jump-related biomechanical variables and physical fitness in female indoor volleyball players. Based on the individual needs of the athletes, practitioners may prescribe one type of surface preferentially over another to maximize the benefits derived from PJT.

Objective: The number of people suffering from depression and/or anxiety has increased steadily due to the coronavirus disease 2019 (COVID-19) pandemic. In this context, web-based exercise interventions have emerged as a potential treatment strategy. The objective of this study was to synthetize evidence from randomized controlled trials regarding the effects of web-based exercise interventions on patients with depressive and/or anxiety disorders. Methods: Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. Six databases were searched (Cochrane Library, EBSCO, PubMed, SciELO, Scopus, and Web of Science), and eligible articles were identified according to a PICOS inclusion-exclusion approach (participants with depressive or anxiety disorders; web-based exercise interventions; active or passive control group; assessment of changes in depressive or anxiety disorders; randomized design). Primary outcomes were depressive and/or anxiety symptoms. The quality of evidence was assessed with Grading of Recommendations Assessment, Development, and Evaluation. Results: Of 7,846 search results, three studies met the inclusion criteria (172 participants between 18 and 65 years of age, 95.9% women). The web-based exercise interventions lasted 8-12 weeks and involved endurance training, yoga, or combined endurance and strength training. The comparators involved non-exercise controls or active controls. Compliance rates were low. Web-based exercise interventions were not superior to controls regarding anxiety symptoms, and only one study found benefits for depressive symptoms (p ≤ 0.05). The quality of the cumulative evidence was low. Conclusion: The available data regarding the effects of web-based exercise interventions on depression and/or anxiety symptoms is scarce, the risk of bias is high, and the quality of the cumulative results is low. Currently, no clear recommendations can be provided. Registration number: PROSPERO CRD42021225938.

Simple Summary Interval training (IT) is a popular training strategy recognized by its positive effects on metabolic and cardiovascular system. However, there seems no consensus regarding the effects of IT on immune system parameters. Therefore, we aimed to summarize the evidence regarding the effects of IT on the immune system. As our many findings, an IT acutely promote a transitory change on immune cell count followed by reduced function. The magnitude of these changes seems to vary in accordance with IT type. On the other hand, the regular practice of IT might contribute to improve immune function without apparent change on immune cell count. Abstract Purpose: To summarize the evidence regarding the acute and chronic effects of interval training (IT) in the immune system through a systematic review with meta-analysis. Design: Systematic review with meta-analysis. Data source: English, Portuguese and Spanish languages search of the electronic databases Pubmed/Medline, Scopus, and SciELO. Eligibility criteria: Studies such as clinical trials, randomized cross-over trials and randomized clinical trials, investigating the acute and chronic effects of IT on the immune outcomes in humans. Results: Of the 175 studies retrieved, 35 were included in the qualitative analysis and 18 in a meta-analysis. Within-group analysis detected significant acute decrease after IT on immunoglobulin A (IgA) secretory rate (n = 115; MD = −15.46 µg·min−1; 95%CI, −28.3 to 2.66; p = 0.02), total leucocyte count increase (n = 137; MD = 2.58 × 103 µL−1; 95%CI, 1.79 to 3.38; p < 0.001), increase in lymphocyte count immediately after exercise (n = 125; MD = 1.3 × 103 µL−1; 95%CI, 0.86 to 1.75; p < 0.001), and decrease during recovery (30 to 180 min post-exercise) (n = 125; MD = −0.36 × 103 µL−1;−0.57 to −0.15; p < 0.001). No effect was detected on absolute IgA (n = 127; MD = 47.5 µg·mL−1; 95%CI, −10.6 to 105.6; p = 0.11). Overall, IT might acutely reduce leucocyte function. Regarding chronic effects IT improved immune function without change leucocyte count. Conclusion: IT might provide a transient disturbance on the immune system, followed by reduced immune function. However, regular IT performance induces favorable adaptations on immune function.

Studies comparing children and adolescents from different periods have shown a decrease in physical activity and fitness in the last decades (Moliner-Urdiales et al., 2010; Runhaar et al., 2010; Cohen et al., 2011; Hardy et al., 2013; Santtila et al., 2018; Masanovic et al., 2020; Fuhner et al., 2021). Low physical fitness is associated with poor metabolic health, independent of central adiposity (Latt et al., 2018). Moreover, changes in physical fitness from childhood and adolescence to adulthood are related to metabolic health, physical activity levels, and bone mineral density (Garcia-Hermoso et al., 2019; Maestu et al., 2020), while both low cardiorespiratory fitness and muscle strength are associated with higher risk of premature death and disability (Ortega et al., 2012; Henriksson et al., 2019a,b). Obesity is another important concern (Wijnhoven et al., 2014; Ogden et al., 2016; Bentham et al., 2017), but previous studies have shown that increased physical activity might be associated with decreased adiposity (Hui et al., 2021) and can modulate the effects of genetic predisposition to obesity in young people (Todendi et al., 2021). The negative impact of a sedentary lifestyle during early life has been largely debated (Faigenbaum et al., 2011; Faigenbaum and Myer, 2012; Stracciolini et al., 2013). In the early 60s, Kraus and Raab (1961) stressed the importance of physical activity for preventing diseases and suggested that the adverse health effect of physical inactivity was comparable to lack of vitamins or contagious diseases. Based on this, Faigenbaum et al. (2013) proposed a population-wide approach for identifying inactive children, prescribing interventions and raising public awareness. Notwithstanding, some important barriers for physical activity adoption among children and adolescents might be considered, like perception of lack of safety, physical environment and lack of support (Stankov et al., 2012; Lu et al., 2014; Martins et al., 2014). It is also important to consider children and adolescents particularities (e.g., biological and behavior characteristics) when prescribing and evaluating exercise programs, since exercise programs designed for adults might be inadequate for them (Faigenbaum et al., 2013). Previous studies suggested that young people naturally engage in intermittent activities (Bailey et al., 1995) and high intensity activities might be particularly beneficial to improve cardiorespiratory fitness (Baquet et al., 2003; Costigan et al., 2015), mental health (Leahy et al., 2020), body composition (Costigan et al., 2015; D et al., 2019) cardiovascular risk and metabolic health (Cooper et al., 2016; Garcia-Hermoso et al., 2016; MA et al., 2021) in children and adolescents. The purpose of the current article is to present the benefits of high-intensity multimodal training (HIMT) programs, such as CrossFit, to the youth, with a critical discussion about its potential benefits and concerns.

This study aimed to examine inter-limb jump asymmetries and their association with sport-specific performance in young swimmers. Thirty-eight (male, n = 19, female, n = 19) regional/national level young swimmers (age: 12.3 ± 1.2 years, height: 159.6 ± 8.2 cm, body mass: 52.5 ± 9.2 kg) participated in this study. Inter-limb asymmetries were assessed for single-leg countermovement jump (SLCMJ) and single-leg standing long jump (SLSLJ). Sport-specific performance was evaluated using front crawl (i.e., 50 m and 25 m) and front crawl kick (i.e., 50 m and 25 m). The kappa coefficient revealed a “slight” level of agreement (Κ = 0.156, 0.184, and 0.197 for female, male, and all, respectively) between the direction of asymmetry for SLCMJ and SLSLJ, indicating that asymmetries rarely favored the same limb during both tests. A paired sample t-test showed a significant difference (p = 0.025) between asymmetry scores obtained in SLCMJ and SLSLJ. No significant difference was found in asymmetry scores between males and females (p = 0.099 to 0.977). Additionally, no association between asymmetry scores and sport-specific performance was observed (p &gt, 0.05). Our findings highlight the independent nature of inter-limb asymmetries derived from SLCMJ and SLSLJ among young male and female swimmers. Further, our results suggest no association between jumping asymmetries and sport-specific performance.

Through evolution, several animal species, including humans, have evolved the ability to jump. Indeed, jumping actions are common for mammals, reptiles, and insects, among others. For humans, jumping allow them to perform a wide range of activities, from dancing to moon exploration. From a sports medicine perspective, jumps have been used by athletes as a training method in preparation for competitions at least in the last 3,000 years

Rodríguez-Fernández, A, Sanchez-Sanchez, J, Ramirez-Campillo, R, Nakamura, FY, Rodríguez-Marroyo, JA, and Villa-Vicente, JG. Relationship between repeated sprint ability, aerobic capacity, intermittent endurance, and heart rate recovery in youth soccer players. J Strength Cond Res 33(12): 3406-3413, 2019-To investigate the relationship between repeated sprint ability (RSA) and several aerobic and anaerobic-related soccer-performance indicators, 45 youth soccer players (age 16.8 ± 0.1 years) were classified into "high" (HAF) or "low" aerobic fitness (LAF) (VO2max ≥ or60 ml·kg·min, respectively) and completed an RSA test measuring best (RSAbest), mean (RSAmean), total sprint time (RSAtotal), and percent sprint decrement (Sdec). A laboratory VO2max test (LabTest) together with anaerobic threshold (VT) and peak speed was measured (vLabTest). In addition, a 20-m multistage shuttle run test (MSRT) and a soccer-specific test (TIVRE-Soccer test-TST) were completed. Heart rate (HR) and HR recovery (HRR) were measured during all tests. High aerobic fitness presented greater (p ≤ 0.05) performance in LabTest, MSRT and TST, at maximal effort, at VT, as well as faster HRR. RSA was similar between HAF and LAF. Contrary to HAF, LAF showed negative correlation between vLabTest with RSAmean (r = -0.6, p = 0.000) and Sdec (r = -0.4, p = 0.044). Also, LAF showed negative correlation between TST end speed (vTST) and RSAmean (r = -0.5, p = 0.005) and Sdec (r = -0.5, p = 0.003). In LAF, RSA was strongly correlated with locomotor factors (e.g., vTST; VT) in both laboratory and field tests. Athletes with high total HRR (12.5%) in TST presented better (p ≤ 0.05) Sdec in the RSA test. The multiple regression revealed that the LAF vLabTest explained 44.9, 40.0, and 13.5% of the variance in RSAbest, RSAmean, and Sdec, respectively. Practitioners may consider these findings to optimize youth athletes' assessment and preparation processes.

This study examined the effects of 8-week stretch-shortening cycle-based (SSC-based) versus non-SSC-based jump exercises on physical fitness in prepubertal male soccer players. Twenty-six participants were randomly assigned to either a SSC-based using countermovement jump (CMJG; n = 13) or a non-SSC-based jump group using squat jump (SJG; n = 13). Pre- and post-training, tests were conducted to assess measures of muscle power (countermovement jump, reactive strength index), speed (5 m, 20 m), change of direction (CoD), and sport-specific performance (maximal kicking distance). To establish the effect of the interventions on the dependent variables, a 2 (group: CMJG and SJG) × 2 (time: pre, post) ANOVA with repeated measures was determined for each parameter. Findings demonstrated a main effect of time for countermovement jump, reactive strength index, and maximal kicking distance (p 0.05; ES = 0.05). Overall, jump exercises which utilize the SSC seem to be more effective in improving measures of speed and muscle power performance in young athletes. However, jump exercises that do not involve the SSC appear to negatively affect CoD performance in young athletes.

Purpose: To analyze the effects of a 9-week plyometric training program on the sprint times (5, 10, 20, and 30 m), change-of-direction speed (modified T test and modified Illinois test), jumping (squat jump, countermovement jump, countermovement jump with arms, and horizontal 5-jump test), upper-body strength (right and left handgrip, back extensor strength, and medicine ball throw), and balance (Y and stork balance tests) of female handball players. Methods: Athletes were randomly divided into experimental (n = 21; age = 13.5 [0.3] y) and control (n = 20; age = 13.3 [0.3] y) groups. Training exercises and matches were performed together, but the experimental group replaced a part of their normal regimen by biweekly upper- and lower-limb plyometric training. Results: Both groups improved performance, but to a greater extent in the experimental group compared with controls for 20- and 30-m sprint times (Δ% = 9.6, P d = 0.557 and Δ% = 20.9, P d = 1.07, respectively), change of direction (T test: P d = 0.993 and Illinois test: P d = 0.769), vertical and horizontal jumping (P P P d = 1.07). Conclusions: A plyometric training program allows female junior handball players to improve important components of their physical performance.