Jump Performance Research Articles

Phenotypic associations between linearly scored traits and sport performance in the Swedish Warmblood horse population

The goal for most warmblood studbooks is to produce horses that are internationally competitive in sports like show jumping or dressage. The linear scoring system, describing the horse between two biological extremes, is commonly used for a more objective assessment of young horses in many studbooks. However, few studies have examined the phenotypic association between traits linearly scored at a young age and sport performance, and whether there might be an intermediate optimum on the linear scale. This study investigated the phenotypic association between linearly scored traits and competition performance in show jumping or dressage, using the results of linear scoring from young horse performance tests between 2013 and 2021 and competition data between 2014 and 2021 for Swedish Warmblood horses. Sport performance was defined as lifetime accumulated points achieved in show jumping or dressage competitions. Horses were classified as jumping (J) or dressage (D) horses according to their sires’ and grandsires’ classification. In total, 48 linearly scored traits, assessed on a biological scale from A to I, were analyzed. The phenotypic association between the linear score for each trait and sport performance was studied using linear models for sport performance including fixed effects of sex, birth year and linear and quadratic regression on adjusted linearly scored trait values. Significant differences in LS means between J and D horses were found for all linearly scored traits except for length of body and five traits referring to leg conformation. For J horses, 25 linearly scored traits (eight conformation traits, three gait traits, 13 jumping traits and one behavior trait) were found to be significantly associated (p < 0.05) with show jumping performance. A majority of these traits (21 out of 25 traits) showed a linear association with performance, indicating that stronger expression (towards A on the assessment scale) was favorable for performance in show jumping in J horses. For D horses, 21 linearly scored traits (eleven conformation traits and ten gait traits) were significantly associated with dressage performance. Most of these traits (15 out of 21 traits) showed a linear association with performance, while six traits showed an association with optimal scores, indicating that breeding for more extreme expression of the specific trait is not associated with better sport performance. These results underline the importance of linearly scored traits as indicator traits of later sport success.

The Effects of Regional Muscle Strength and Mass on Standing Long Jump Performance

Muscle strength and mass strongly influence performance. The role of the trunk, upper limbs, and lower limbs in a specific performance is important but unclear in terms of muscle strength, muscle mass, and the degree of influence of each part. Standing long jump is a performance that produces results by not only the muscles of the lower limbs working together but also the entire body, including the trunk and upper limbs. To determine the influence of muscle strength and the mass of each body part on standing long jump, 31 healthy young adults (18 males and 13 females) participated in this study. Abdominal trunk muscle strength, grip strength, and knee extension muscle strength were measured, each of which was defined as trunk, upper limb, and lower limb muscle strength. The trunk, upper limb, and lower limb muscle masses were measured using a body composition analyzer. Performance was measured using the standing long jump test (jumping power). Factors influencing standing long jump were examined. A multiple regression analysis revealed that trunk (β = 0.367, p = 0.006) and upper limb (β = 0.608, p &lt; 0.001) muscle strength values were extracted for standing long jump (adjusted R2 = 0.574, p &lt; 0.01). Trunk and upper limb muscle strength influence standing long jumps.

Height, Push-Off Angle, Explosive Power: Do they Correlate with Volleyball Athlete Jumping Performance?

Background and Study Aim: Jump performance is the main asset in attacking volleyball. Jump performance is influenced by various factors that affect this indicator, such as body balance, upper and lower body coordination, as well as explosive power. The purpose of this study was to investigate the relationship between height, push-off angle, explosive power, and jumping performance in volleyball student athletes. Material and Methods: The method used was a correlational, 7 male volleyball student athletes as samples (age = 21.00 ± 1.732 years, height = 167.86 ± 1.864 cm). Sampling technique used is purposive sampling, Shapiro-Wilk and Levene's test to determine normality and homogeneity. Data calculations were processed using the help of IBM SPSS version 26.0., with decision making p &lt; 0.05. Results: Variable Push-Off Angle and Explosive Power show significant results (p &lt; 0.05). The Pearson correlation value for Push-Off Angle is -0.781, while the correlation value for Explosive Power is 0.908. Conversely, the variable Height does not show significant results (p &gt; 0.05), with a Pearson Correlation value of -0.334. The findings indicate that the aspect of Explosive Power provides a significant contribution with a positive relationship. This is followed by the aspect of Push-Off Angle, but the results show that this aspect provides a moderate contribution with a negative relationship. Additionally, the aspect of Height shows a negative relationship and a low contribution value. Conclusions: The Study’s findings conclude that Push-Off Angle and Explosive Power have a significant correlation and play a crucial role in enhancing Jump Performance. However, Body Height does not exhibit a significant correlation with Jump Performance. These findings also conclude that the aspect that plays a crucial role in jump performance is explosive power.

The Acute Effect of Dynamic vs. Proprioceptive Neuromuscular Facilitation Stretching on Sprint and Jump Performance.

Participating in sports has been shown to promote overall wellness and, at the same time, reduce health risks. As more people are participating in sports, competitions have increased, and every aspect of the game has been focused by coaches and athletes in order to improve performance. One of these aspects is the warm-up session. The purpose of this study was to investigate the acute effect of a dynamic warm-up versus a proprioceptive neuromuscular facilitation (PNF) warm-up on the sprint and jump performance of recreationally active men. Thirty (n = 30) males were randomly assigned to undergo three sessions of different warm-up types, 72 h apart, involving either proprioceptive neuromuscular facilitation (PNF), dynamic stretching (DS), or no stretching session (control). The PNF and dynamic modes of stretching improved vertical jump performance, F (2.58) = 5.49, p = 0.046, to a certain extent (mean + 3.32% vs. control, p = 0.002 for dynamic and mean + 1.53% vs. control, p = 0.048 for PNF stretching). Dynamic stretching is best used to get a better vertical jump height. Sprint performance was also increased to a greater extent following the stretching session, F (2.58) = 5.60, p = 0.01. Sprint time was +1.05% faster vs. the control, with a value of p = 0.002 after dynamic stretching, while PNF stretching demonstrated a sprint time of +0.35% vs. the control, with a value of p = 0.049. Dynamic stretching showed a better sprint performance and also vertical jump height performance in this study. PNF and dynamic stretching prove to be equally efficacious in flexibility conditioning depending on the type of movement involved. This type of stretching should be utilized to help preserve or improve the performance output of physical activity, especially in sprinting and jumping events.

Theoretical analysis of the physiological and technical aspects of jumping from a trampoline within the limits of skiing

Skiing, and especially ski jumping, is characterized by high intensity and a high level of technical complexity. The presented scientific study is devoted to a detailed analysis of the physiological and technical aspects of ski jumping within the scope of skiing. The main goal of this study is to highlight the features of the functional training of athletes and to analyze the key technical elements that are of decisive importance for the successful performance of this specific discipline.&#x0D; The article pays considerable attention to the importance of physiological training as a necessary factor for achieving high results in this demanding sport. A detailed overview of the technical aspects that affect the quality and performance of ski jumping is also provided. A deep understanding of the relationship between physiological performance and technical skills in this field can lead to decisive conclusions.&#x0D; The obtained research results can play a significant role in improving the quality of training programs and training systems for athletes in the field of skiing. This will contribute not only to increasing the efficiency of jumping from the ski jump, but also to ensure an increased level of safety for athletes who are engaged in this exciting discipline.

Maximum Strength and Power as Determinants of Match Skating Performance in Elite Youth Ice Hockey Players.

Keiner, M, Kierot, M, Stendahl, M, Brauner, T, and Suchomel, TJ. Maximum strength and power as determinants of match skating performance in elite youth ice hockey players. J Strength Cond Res 38(6): 1090-1094, 2024-Maximum strength has a strong influence on speed-strength performances such as sprints and jumps. Important for sports practice is whether these findings are also reflected in game performance. Therefore, the aim of this study was to explore the influence of maximum strength and power performance on linear on-ice skating performance in testing and during game play. A cross-sectional study was conducted, and 24 highly trained male youth ice hockey players participated. Jump performances (countermovement jump [CMJ], drop jumps), maximum strength (1 repetition maximum [1RM] squat and isometric trap bar pull [ITBP]), and on-ice linear sprints (15 m [LS15], 30 m [LS30], flying 15 m [FLY15]) were measured. Match performances (among others: peak skating speed) were collected of 4 regular league games using a local positioning system. Correlation coefficient and explained variance were calculated ( ρ ≤ 0.05). Correlations between maximum strength and jump with on-ice linear sprint performance showed 1-35% explained variance. Correlations between "off ice" test (CMJ, relative 1RM) and game data (peak skating speed) showed 22-30% explained variance, respectively, while ITBP and DJ missed significant level. Between linear sprint and game performance showed 15-59% explained variance. In this study, a clear influence of 1RM in squatting and CMJ performance on on-ice linear sprint as well as in-game peak skating speed was observed. These findings show that strength and jumping performance can be valuable tests within a comprehensive test battery and indicate the relevance of strength and jumping tasks within the regular exercise program to improve in-game skating performance.

Agreement between Inter-Limb Asymmetries in Single and Triple Unilateral Hops, and Associations with Bilateral Jumping and Sprint Performance in U17 and U19 Soccer Players

The purpose of this study was to investigate the agreement regarding the direction of interlimb asymmetry (ILA) between different horizontal jumping tests, to examine the differences in ILA between different age categories and to assess the relationship between ILA and sprint and jump performance. The sample included 38 elite youth male soccer players from two distinct age categories (U17 and U19). The testing procedure consisted of a 10 m sprint test, unilateral and bilateral broad jumps, and unilateral and bilateral triple hops. The results showed moderate correlation and fair agreement in the direction of ILA between single broad jumps and single-leg triple hops (κ = 0.42; p = 0.014). The magnitude of ILAs tended to be larger in the unilateral triple hop (5.41 ± 5.25%) compared to the unilateral single hop (3.54 ± 2.67%). Furthermore, the older group had smaller ILA magnitudes in both jumping tests, with significant differences between age groups being observed only in single hops (p = 0.46; d = 0.78). Additionally, significant associations were found only between the ILA unilateral triple hop with bilateral single jump (r = −0.39) and sprint performance (r = 0.40), while ILA in the broad jump showed no significant associations with performance metrics. Based these results, the unilateral triple hop could be recommended as the preferred horizontal jump variation for screening soccer players. Furthermore, in line with the literature, mean ILA in horizontal jumps were far below the commonly used threshold of &gt;10–15% (mean ILA 3.5–6.5%), which suggests that the ILA threshold for horizontal jumps should be reconsidered.

Acute Effect of Kinesio Taping on Balance, Agility, and Jumping Performance in Tennis Players

Acute Effect of Kinesio Taping on Balance, Agility, and Jumping Performance in Tennis Players

Coalescence-Induced Jumping of Nanodroplets in a Perpendicular Electric Field: A Molecular Dynamics Study.

Coalescence-induced jumping has promised a substantial reduction in the droplet detachment size and consequently shows great potential for heat-transfer enhancement in dropwise condensation. In this work, using molecular dynamics simulations, the evolution dynamics of the liquid bridge and the jumping velocity during coalescence-induced nanodroplet jumping under a perpendicular electric field are studied for the first time to further promote jumping. It is found that using a constant electric field, the jumping performance at the small intensity is weakened owing to the continuously decreased interfacial tension. There is a critical intensity above which the electric field can considerably enhance the stretching effect with a stronger liquid-bridge impact and, hence, improve the jumping performance. For canceling the inhibition effect of the interfacial tension under the condition of the weak electric field, a square-pulsed electric field with a paused electrical effect at the expansion stage of the liquid bridge is proposed and presents an efficient nanodroplet jumping even using the weak electric field.

Kinetic Analysis, Potentiation, and Fatigue During Vertical and Horizontal Plyometric Training: An In-Depth Investigation Into Session Volume.

To investigate vertical and horizontal jump kinetic performance following a low-volume plyometric stimulus with progressively increased session jump volume. Sixteen academy rugby players (20.0 [2.0]y; 103.0 [17.6]kg; 184.3 [5.5]cm) volunteered for this study. Vertical and horizontal jump sessions were conducted 1 week apart and consisted of a 40-jump low-volume plyometric stimulus using 4 exercises, after which volume was progressively increased to 200 jumps, using countermovement jump (CMJ) for vertical sessions and horizontal broad jump (HBJ) for horizontal sessions. Jump performance was assessed via force-plate analysis at baseline (PRE-0), following the low-volume plyometric stimulus (P-40), and every subsequent 10 jumps until the end of the session (P-50, P-60, P-70, . . . P-200). The low-volume stimulus was effective in potentiating HBJ (2% to 5%) but not CMJ (0% to -7%) performance (P < .001). The HBJ performance enhancements were maintained throughout the entire high-volume session, while CMJ realized small but significant decrements (-5% to -7%) in jump height P-50 to P-80 before recovering to presession values. Moreover, increases in eccentric impulse (5% to 24%; P < .001) in both sessions were associated with decreased or maintained concentric impulse, indicating a breakdown in performance-augmenting mechanisms and less effective power transfer concentrically after moderate volumes. Practitioners should consider kinetic differences between HBJ and CMJ with increasing volume to better inform and understand session dosing strategies.

Recovery during Successive 120-min Football Games: Results from the 120-min Placebo/Carbohydrate Randomized Controlled Trial.

This study aimed to examine the recovery kinetics (i.e., time-dependent changes) of performance-related variables between two 120-min male football games performed 3 d apart with and without carbohydrate supplementation. Twenty male players (20 ± 1 yr; body fat, 14.9% ± 5.1%; maximal oxygen consumption, 59.4 ± 3.7 mL·kg -1 ·min -1 ) participated in two 120-min football games (G1, G2) according to a randomized, two-trial, repeated-measures, crossover, double-blind design. Participants received carbohydrate/placebo supplements during recovery between games. Field activity was monitored during the games. Performance testing and blood sampling were performed before and at 90 and 120 min of each game. Muscle biopsies were collected at baseline and at 90 and 120 min of G1 and pre-G2. Compared with G1, G2 was associated with reduced total distance (10,870 vs 10,685 m during 90 min and 3327 vs 3089 m during extra 30 min; P = 0.007-0.038), average (6.7 vs 6.2 km/h during extra 30-min game-play; P = 0.007) and maximal speed (32.2 vs 30.2 km/h during 90 min and 29.0 vs 27.9 km/h during extra 30 min; P < 0.05), accelerations/decelerations ( P < 0.05), and mean heart rate ( P < 0.05). Repeated sprint ability ( P < 0.001), jumping ( P < 0.05), and strength ( P < 0.001) performance were compromised before and during G2. Muscle glycogen was not restored at G2 baseline ( P = 0.005). Extended game-play reduced lymphocyte, erythrocyte counts, hematocrit, hemoglobin, reduced glutathione ( P < 0.05) and increased delayed onset of muscle soreness, creatine kinase activity, blood glycerol, ammonia, and protein carbonyls ( P < 0.05) before and during G2. Pax7 + ( P = 0.004) and MyoD + cells ( P = 0.019) increased at baseline G2. Carbohydrate supplementation restored performance and glycogen, reduced glycerol and delayed onset of muscle soreness responses, and increased leukocyte counts and Pax7 + and MyoD + cells. Results suggest that extended football games induce a prolonged recovery of performance, which may be facilitated by carbohydrate supplementation during a congested game fixture.

Determining the Relationship between Squat Jump Performance and Knee Angle in Female University Students.

The Squat Jump (SJ) test is widely recognized as a reliable test for assessing lower-limb explosive strength. However, uncertainty persists in the literature regarding the optimal starting positions for maximizing vertical jump performance. This uncertainty is exacerbated by a disproportionate focus on athletes in existing studies, with insufficient consideration being given to non-athletic women. To address this gap, this study investigated the influence of leg starting angle on explosive jump height in a homogeneous sample of non-athletic women. Thirty-two female students enrolled in a Sports Science master's degree program at the University of Salerno participated in the study. Descriptive statistics were employed to summarize data on various variables, and Pearson's correlations were calculated to assess the relationship between knee angle in the starting position and achieved jump height. The study revealed that different starting positions had a noteworthy impact on jump height among the participants. A strong negative correlation (-0.701) was identified between Squat Jump elevation and the knee angle in the starting position. Notably, 62.5% of the subjects opted for a starting knee position of approximately 70 degrees, with all of them consistently achieving a jump height associated with this specific angle. These findings provide valuable insights into the relationship between leg starting angle and explosive jump height in non-athletic women. The observed correlation underscores the significance of the starting position in Squat Jump performance. The prevalence of a specific knee angle choice among participants suggests potential implications for training and performance optimization in this sample.

Is There a Relationship Between Birth Quartile and Vertical Jump Performance Among Young Male Elite Volleyball Athletes?

Vertical jump is an important skill that influences volleyball performance. In this study, we analyzed the relationship between vertical jump performance and birth quartile of Brazilian male youth volleyball players. We calculated chi-square goodness-of-fit tests to compare the athletes' birthdate distributions in quarters of their birth years (Q1, Q2, Q3, and Q4) according to player age categories (U17, U18, U19, and U21). We calculated one-way ANOVAs to compare spike jump and block jump heights of players born in different quarters of the same year. Overall, we found a relative age effect (i.e., more players with birth dates early in the birth year) in U17 (p < .001), U18 (p < .001), U19 (p < .001), and U21 (p = .04). Regarding vertical jump performance, U18 athletes born in Q2 reached higher spike jump heights (p = .006) and block jump heights (p = .002) than athletes born in Q4, and U19 athletes born in Q1 reached higher block jump heights than athletes born in Q3 (p = .049). There were no significant differences in vertical jump performance across birth quartiles among U17 and U21 athletes. Thus, a relative age effect was present in all age categories but not always reflected in vertical jump performance. Volleyball coaches and policymakers are still advised to employ strategies to ensure fairer opportunities for players born later in the year of their eligibility dates, as we found RAE to be sometimes, but not always, related to higher spike or block jump heights even among these older adolescents and young adult athletes.

Effects on strength, jumping, reaction time and perception of effort and stress in men´ s top-20 World Padel Competitions

Paddle tenis has experienced significant growth in recent years, becoming one of the most popular and globally expanding sports. This study aims to examine the physiological performance and subjective perception of stress and fatigue in top-20 padel players during matches. Seven elite players participated in the study. Various variables were evaluated, such as subjective perception of effort and stress, isometric grip strength, reaction time, and jump performance, both before and after the matches. The results showed significant increases in subjective perception of effort, perceived stress, and performance in vertical countermovement and squat jumps, as well as in horizontal jumps after the matches. However, no significant changes were observed in reaction time, free-arm jumps, and grip strength (although significant differences were observed between the dominant and non-dominant hand). These findings suggest that the physical conditioning of high-level padel players allows them to endure the fatigue of matches. The differences between the dominant and non-dominant hand indicate asymmetries due to the one-sided nature of this sport. Reaction time did not decrease, suggesting that the level of fatigue was not sufficient to limit the information processing of these athletes. Perceived stress, with widely dispersed values far from the maximum, was consistent with the reaction and adaptation times of the players. The repeated decelerations and accelerations from the backcourt to the net (and vice versa) did not produce excessive fatigue but rather muscular activation, which was evident in horizontal jumps. These findings contribute to understanding the physiological aspects of padel and can be used for the development of training programs that optimize performance and minimize the perception of fatigue in players.

Effect of Music and Lemon Aroma on Anaerobic Power and Balance of Athletes After Exhausting Activity

Background: The aim of this study was to investigate the effect of lemon aroma (LA) and music on anaerobic power and balance in athletes following sporting activity. Recognizing the potential influence of sensory stimuli on performance, we sought to contribute valuable insights into optimizing recovery strategies for athletes. Objectives: The primary objective was to assess the effects of LA and music on anaerobic power and balance, employing a comprehensive set of physical fitness factors. Methods: Twelve male amateur athletes were randomly included in our study. These individuals were given LA, music, and with no supplementation (control) for 72 hours, followed by a standardized recovery phase using a Monarch ergometer, and lactic acid levels were measured after the intervention to assess the physiological effect. Balance analysis covering both static and dynamic conditions was performed using a specialized balance machine. Isometric dynamometer measurements and detailed assessments of Sargent's jumping performance were performed to analyze physical fitness factors. Results: Significant differences were observed in balance parameters, with both static balance (SB) and dynamic balance (DB) registering higher values in the control time (P = 0.006; P &lt; 0.001, respectively). Lemon aroma exposure resulted in the highest values for peak power (PP) and relative PP (RPP) (P &lt; 0.001; P &lt; 0.001, respectively). Conversely, in the control time exhibited the lowest values for relative anaerobic power (RAP) and vertical jump (VJ). Conclusions: The findings suggest a positive influence of stimulating aroma (lemon) and music elements on sportive performance. Lemon aroma was associated with enhanced anaerobic power, while the control group exhibited superior balance outcomes. These results underscore the potential benefits of incorporating sensory interventions into athletes' recovery protocols for optimized performance.

Exploring the Implications of Inter-Limb Asymmetries on Sprint, Agility, and Jump Performance in Young Highly-Trained Basketball Athletes: Is There a Relevant Threshold?

Background and Objectives: This study aimed to investigate the magnitude of vertical jump inter-limb asymmetries among young highly-trained basketball athletes and to analyze its impact on sport performance, specifically in sprints, agility, and vertical jumps. Materials and Methods: A unilateral countermovement jump (CMJ) was employed to determine Inter-limb Index Asymmetry (IAI) in 320 participants aged from 14 to 18 years, from the Valencia Basket youth academy. IAI was categorized into three groups: 0-9.9%, 10-14.9%, and >15%. The relationship between IAI and performance variables was analyzed through correlation studies (Pearson or Spearman's). The influence of IAI magnitude was assessed using ANOVA or Kruskal-Wallis analysis, with leg dominance as a covariable. SPSS Statistics version 26 was used for analysis. Results: Among all the participants, the mean IAI was 10.6%. Correlation studies revealed non-significant values (p < 0.05) between IAI and sport performance variables. The three IAI magnitude groups did not show statistically significant differences in sprint, agility, and jump outcomes. Leg dominance did not seem to influence performance outcomes, except for unilateral CMJ. Conclusions: The results obtained challenge the assumption that an IAI above 10% negatively affects sprint, agility, or jump performance in young basketball athletes. Notably, the magnitude of IAI did not influence sport performance parameters, suggesting that the 10-15% threshold from previous studies may not be applicable to this population. The study emphasizes the need to understand lower-limb asymmetries in the context of specific sport task performance, considering the potential evolution over time among affected young athletes.

Effect of Ball Inclusion in Drop Vertical Jump Test on Performance and Movement Variability in Basketball Players

The aim of this study was to assess and compare performance and movement variability (MV) in both bilateral and unilateral vertical drop jumps (DVJs) under conditions involving the incorporation or exclusion of ball catching. Twelve amateur basketball players were recruited for participation in the study (seven females and five males). Participants performed three jumps in each of the six conditions analyzed in randomized order: bilateral DVJ without (BNB) and with ball (BB); unilateral DVJ right leg without (RNB) and with ball (RB); and unilateral DVJ left leg without (LNB) and with ball (LB). MV and DVJ performance parameters were analyzed with an accelerometer and a force platform. MV was quantified using the sample entropy (sample entropy; SampEn) derived from the acceleration of the lower back. Differences between the different DVJ conditions were determined with the Wilcoxon test, with a significance level set at p &lt; 0.05. The comparisons were also assessed via standardized mean differences (Cohen’s d). No significant differences were observed in jump height, contact time and reactive strength index between conditions. However, the RB condition reported higher MV compared to RNB (effect size = 0.79; p = 0.016). Similarly, LNB showed greater MV compared to RNB (effect size = −0.62; p = 0.042). The inclusion of the ball in the DVJ increased the MV in the bilateral condition and in the right leg, but not in the unilateral condition with the left leg. The asymmetry between legs (right vs. left) in MV values in NOBALL conditions was higher (≈15%) compared to the BALL condition (≈5%).

The Comparative Study on Effectiveness of Plyometric Vs Pilates Exercises on Increasing Vertical Jump Performance among Basketball Players

The Comparative Study on Effectiveness of Plyometric Vs Pilates Exercises on Increasing Vertical Jump Performance among Basketball Players

Contextual factors in understanding the jumping performance of young football goalkeepers

The aim of this study was to examine the effect of various contextual factors, such as relative age, biological maturation, or competitive level, on the jumping performance of young football goalkeepers. Vertical jump performance was evaluated in a selection of goalkeepers (n = 110) from U-14 and U-16 category teams. The sample was categorized by relative age, biological maturation, and competitive level. The results revealed a trend in the overall sample towards an overrepresentation of goalkeepers born in the early months of the year. Maturity status influenced the most in jumping performance of young goalkeepers (SJ: F = 11.27, p < .001, ηp2 = 0.187; CMJ: F = 8.72, p < .001, ηp2 = 0.162; AJ: F = 8.37, p < .001, ηp2 = 0.146), while the birth quartile had no effect on the jumping performance in the sample. Statistical differences were significant for SJ and CMJ between competitive level groups in the U-14 group only. (F = 5.37, p = .008, ηp2 = 0.186) and CMJ (F = 4.54, p = .016, ηp2 = 0.159). This study showed a greater association between maturation and jumping performance in young football goalkeepers rather than with relative age, which could influence the selection process in this field position at early ages.

Effect of 1-Week Weight Loss While Maintaining Total Body Water on Jump Performance.

Jumping performance is influenced by body composition and excess fat mass impairs performance. Maintaining optimal fat mass and fat-free mass (FFM) is crucial for enhancing jump height. However, there is limited evidence on short-term weight loss programs that reduce fat mass without water restriction and their effects on muscle function and jumping performance. This study aimed to clarify the effects of a 1-week weight loss program on jumping height and muscle function of volleyball players. The weight loss group engaged in two 40 min slow-paced jogging sessions in addition to their daily training routine. Energy intake was restricted without limitations on water intake. Total body water and body composition using the deuterium dilution method, muscle strength, and jump height before and after 1 week were evaluated for those in the weight loss and control groups. Body mass was significantly reduced in the weight loss group (-2.7 ± 1.3%, p < 0.05) with a significant reduction in fat mass (-17.7 ± 10.7%, p < 0.05). Meanwhile, there were no significant changes in total body water or FFM. Muscle strength and power tests indicated no significant differences between the groups; no notable differences were observed in handgrip strength or knee extension torque. The height of a single vertical and continuous jump remained consistent pre- and postintervention in the control group. In the weight loss group, although the height of a single vertical jump exhibited a slight decline postintervention, the height of a continuous jump displayed no significant changes. The short-term weight loss program significantly reduced fat mass without compromising muscle function, which is crucial for sports performance. These findings may benefit other athletes who require fat mass reduction while maintaining muscle function and help create new programs during specific training phases.