Jump Test Research Articles

Psychomotor Therapy Using the Body Schema for the Intellectually Disabled at the A.D.A.R-Tubahoze Centre

This study is the preliminary research focused on psychomotor therapy and body schemas for the intellectually disabled, hence the motor dimension with a test of balance, coordination and jumping in the pre-test and post-test of a BPM measurement at 60, 90 and 120 (BPM) with the YO and YC. The cognitive dimension with, for example, the Berces and Lezine test of body control and latero-spatial organization, the Piaget and Head tests of gesture imitation and latero-spatial organization. The affective dimension revolving around self-esteem was measured with the self-perception profile for adults with intellectual disabilities (SPPD) on physical appearance, athletic competence and psychomotor competence. At the end of the verification of research question and using methodological approach adopted on the present study on the motor dimension, the cognitive dimension and the affective dimension; it was found that with the motor dimension on the balance test, a trend on the performance of our intellectually disabled patients from A.D.A.R-Tubahoze centre during the psychomotor therapy sessions was tested positive in the post-test compared to the pre-test (BYO and BYC).With regard to the coordination test (CYO and CYC) at post-test and pre-test, the statistical frequencies with overall averages show that our intellectually impaired patients tended to obtain better results at post-test than at pre-test; this shows a success in the applicability of motor therapy to coordination disorder in intellectually impaired patients. Similarly, a positive performance trend was shown in the results of the jumping test at post-test than at pre-test. The trend in the results of the jump test (JYO and JYC) in the post-test than in the pre-test would have shown a positive result after our therapeutic-motor sessions with the IDs of the A.D.A.R. centre. From the cognitive dimension, using the test of imitation of gestures and lateral-spatial on different movements, has a score of 10 points in the test of imitation of simple gestures of hand movements, it would have been observed in MID patients that the test proved positive; with the Piaget’s Head test of latero-spatial organization administered to MID which was evaluated at a score of 40 points, had as a positive performance to all patients who took this test. The results of our work on the affective dimension of the dominant modality “Rather true”, was observed on items 12, 16, 20 and 24 of self-esteem, with physical appearance vis-à-vis items (5,10,18 and 22) and items 5 and 9 and then items 17, 13 and 1 of athletic competence; from items with a “Rather positive” modality with items 11, 3 and 2 3, 7, 15 and 19 of our MID patients that a positive trend on positive appreciation was satisfactorily observable.

Physical Condition of Persid Jember Players Based on Playing Position

Football attracts the attention of many people because of its level of popularity. Football has spread throughout the world and is played by millions of people from children to adults, including in Indonesia. Football competitions in Indonesia are divided into League 1, League 2 (professional) and League 3 (amateur). Persid Jember is an amateur club member of the PSSI East Java (Jatim) Provincial Association (Asprov) which competes in the 2021 East Java League 3. This research aims to determine the physical condition of Persid Jember players in 2021 based on playing position. Tests and measurements were carried out to collect data on leg muscle power using the Standing Long Jump Test, speed using the 30 meter run, agility using the Illinois Agility Test and aerobic endurance using the Multistage Fitness Test (MFT). Analysis of descriptions with the average of each playing position was carried out in this study. The research results show that there are differences in physical conditions between playing positions, but the most significant is that the goalkeeper position is the lowest among the other positions. This research needs to be developed on larger research subjects considering the limitations of only one club.

The Investigation of the Effects of Short-Term Body Weight Loss on Elite Wrestlers on Anaerobic Performance and Reaction Time in Tournament Conditions

Athletes, who engage in wrestling, perform weight adjustment before the competitions like all weight loss category sports. For this reason, weight management is a very important factor prior to matches. When the studies on weight loss are examined, it is seen that athletes lose weight in a short time close to the competition. This study aimed to investigate the effects of short-term body weight loss in elite wrestlers on anaerobic performance and reaction time during tournament conditions. Ten experienced international level male wrestlers participated as a volunteer in this study. Participants lost 5% of their body weight within 48 hours, in 72 hours; 1 kg tolerance was given over 5% of body weight. During this process, body composition measurement, Wingate anaerobic performance test (WAnT), Countermovement Jump (CMJ), and visual and auditory reaction tests were conducted. In this study, a randomized crossover design was used and applications lasted four days. Two-way ANOVA with repeated measures was used for statistical analysis. Due to short-term body weight loss in body composition, total body water (TBW) and fat-free mass (FFM) were significantly reduced. In contrast, there was no statistically significant difference in body fat percentage (BF %), visual and auditory reaction time, CMJ and average power (AP). However, there was a significant increase was seen in Peak power (PP) and fatigue index (FI). The results indicate that 5% loss of body weight within 48 hours caused significant changes in body composition and negatively affected the fatigue index. For this reason, athletes who lose weight should avoid rapid weight-loss practices that will cause sudden changes in body composition in order to maintain their athletic performance.

Warm-up is an efficient strategy to prevent diurnal variation of short-term maximal performance in young basketball players

ABSTRACT The objectives of this study were to investigate: 1) whether there were morning-to-evening differences in short-term maximal performance and 2) the impact of prolonged and specific warm-up on short-term maximal performance diurnal variations in young basketball players. Fifteen basketball players of both sexes (Male = 8; Female = 7; age: 14.4 ± 0.46 yr; weight: 64.7 ± 7.1 kg; height: 175.2 ± 6.6 cm; BMI: 21.1 ± 1.9 kg/m2) completed the following short-term maximal performance tests: CMJ with and without arm swing, Lane Agility Drill, Zig-Zag agility test with and without the ball, Sprint 20 m with and without the ball with the passage at 5 and 10 m. All tests were performed after the 15-min standard warm-up procedure (with static stretching) and/or 25-min specific warm-up (with prolonged running and dynamic stretching) in the morning and evening. Vertical jumping tests and all change-of-direction speed tests (with and without a ball) with superior responses were achieved in the evening after standard warm-up among all participants (p < 0.05). In contrast, superior short-term maximal performance was observed in the morning after prolonged and specific warm-up protocol (p < 0.05). It was concluded that specific and prolonged warm-up protocols are suitable strategy to prevent diurnal variation in short-term maximal performance in young basketball players.

Impact of a short-term nitrate and citrulline co-supplementation on sport performance in elite rowers: a randomized, double-blind, placebo-controlled crossover trial.

Citrulline (CIT) and beetroot extract (BR) have separately shown benefits in rowing performance-related outcomes. However, effects of combined supplementation remain to be elucidated. The main purpose of this research was to study the effects of 1week of daily co-supplementation of 3.5g BR (500mg NO3-) plus 6g CIT on aerobic performance, maximal strength, and high-intensity power and peak stroke in elite male rowers compared to a placebo and to a BR supplementation. 20 elite rowers participated in this randomized, double-blind, placebo-controlled crossover trial completing 1week of supplementation in each group of study: Placebo group (PLAG); BR group (BRG); and BR + CIT group (BR-CITG). 3 main physical tests were performed: aerobic performance, Wingate test and CMJ jump, and metabolic biomarkers and physiological outcomes were collected. The Wingate all-out test showed no between-condition differences in peak power, mean power, relative power, or fatigue index (P > 0.05), but clearance of lactate was better in BR-CITG (P < 0.05). In the performance test, peak power differed only between PLAG and BR-CITG (P = 0.036), while VO2peak and maximum heart rate remained similar. CMJ jumping test results showed no between-condition differences, and blood samples were consistent (P > 0.200). Supplementation with 3.5g of BR extract plus 6g of CIT for 7days improved lactate clearance after Wingate test and peak power in a performance test. No further improvements were found, suggesting longer period of supplementation might be needed to show greater benefits.

The reliability of a linear position transducer for measuring countermovement jump performance in national-level road cyclists.

Jump tests have applications in fatigue monitoring, training intervention evaluations, and talent identification in cycling populations. Due to competitive cycling's inherent travel demands, linear position transducers (LPTs) are suitable for assessing jump performance in this population as they are a mobile and validated technology. Understanding the reliability and sensitivity of LPTs in assessing jump performance in cycling populations is required to support the development of sports science protocols. Using an LPT, this study aimed to determine the reliability and sensitivity of countermovement jump (CMJ) variables in road cyclists. Ten national-level male road cyclists performed three maximal CMJ trials twice per week for two weeks, with an LPT measuring force, power, velocity, repetition rate, vertical distance, and concentric time from each trial. Using the mean and best CMJ results from three trials per testing session, the upper limit 90% confidence interval for the coefficient of variation (CV) and smallest worthwhile change (SWC) determined inter-day and -week reliability (CV ≤ 10%) and sensitivity (acceptable sensitivity = CV ≤ SWC) for CMJ variables. Mean power and force, velocity (mean and peak), vertical distance (VD), and concentric time had acceptable inter-day and -week reliability when using either the mean or best CMJ results (CV upper limit 90% confidence interval range = 3.54-10.13%). Moreover, the CV and SWC were typically lower when based on the mean rather than the best of three CMJ trials. Lastly, poor sensitivity (CV > SWC) was evident for all CMJ variables. CMJ-derived mean power and force, velocity (peak and mean), VD, and concentric time have acceptable inter-day and -week reliability when assessed via an LPT in national-level road cyclists. When using an LPT, sports scientists should consider that, while they typically have poor sensitivity, the reliability of CMJ-derived variables improves when expressed as the mean of three trials in national-level road cyclists.

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.

Evaluating the Efficacy of Eccentric Half-Squats for Post-Activation Performance Enhancement in Jump Ability in Male Jumpers

The purpose of the present study was to investigate effect of post-activation performance enhancement (PAPE) induced by the eccentric half-squat exercise on vertical jump performance in male jumpers. The jumping height, peak power, and work were measured and evaluated in twenty male jumpers (age: 21.2 ± 1.7 years, height: 191.1 ± 3.3 cm, body mass: 81.56 ± 7.3 kg) who participated in the national championship last year. Participants performed five eccentric half-squats at 85% of their one-repetition maximum (1 RM), with a knee angle below 90°, followed by immediate and 2 min delayed jump assessments using the Squat Jump (SJ) and Countermovement Jump (CMJ) tests. Results showed that this specific PAPE protocol did not significantly improve jump performance for the SJ (Height: ES = 0.613, p = 0.462, Work: ES = 0.124, p = 0.231, Power: ES = 0.382, p = 0.125) or CMJ (Height: ES = 0.523, p = 0.368, Work ecc: ES = 0.133, p = 0.505 (only main effect time p &lt; 0.05), Work con: ES = 0.114, p = 0.101, Power ecc: ES = 0.134, p = 0.177, Power con: ES = 0.182, p = 0.195, Leg stiffness: ES = 0.095, p = 0.358) tests. Factors such as stimulus specificity, rest intervals, muscle length, and the balance between potentiation and fatigue may explain these results. This study highlights the complexity of PAPE responses and suggests that a single set of eccentric squats with a short rest may not improve jump performance in male jumpers. Further research is required to optimize the interplay between conditioning stimuli and rest periods to maximize PAPE effects in athletic performance enhancement.

The Relationship Between Various Jump Tests and Baseball Pitching Performance: A Brief Review

ABSTRACT Multidirectional ground reaction forces (GRFs) and jump tests within baseball pitchers provide insight into athletic ability and coordination to produce lower-body force and power. Lower-body power is a biomechanical feature that denotes physiological capacity through dynamic and passive tissue stretch-shortening in transferring energy from the ground through the kinetic chain. Optimized lower-body power may lessen the magnitude of forces on the upper extremity. Insufficient lower-body power may create a greater risk of upper-body injury. Lower-body power and its relationship to ball velocity have been minimally investigated, yet some research points to a correlation between jumping ability and fastball velocity. Because pitching is unilateral, practitioners should consider unilateral jumps to determine the extent of bilateral asymmetry or stride to drive leg differences that can guide training to remediate deficiencies. The purposes of this brief review are to (a) examine factors that influence vertical jump performance among baseball players, (b) examine research on pitching multidirectional GRFs, and (c) examine literature concerning jump performances to baseball pitching performance. Collectively, this review can assist coaches and practitioners in lower-body power testing and training for baseball pitchers.

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%).

Effects of adding dual-task or sport-specific task constrains to jump-landing tests on biomechanical parameters related to injury risk factors in team sports: a systematic review.

Jumping and landing tests are frequently used as a tool to assess muscle function. However, they are performed in a controlled and predictable environment. The physical tests commonly used as part of the criteria for return to sport after injury are often performed with little or no cognitive load and low coordinative demand compared to game-specific actions. The aim of this systematic review was to examine the influence of performing a dual task (DT) or sport-specific task constrains during jump-landing tests on biomechanical variables related to lower limb injury risk in team sports. This systematic review followed the specific methodological guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The search was conducted in the databases Medline (PubMed), Web of Science, Cochrane Plus, and SportDiscus for studies published from 2013 until June 30, 2023. To be eligible, studies had to include: (1) kinematic and/or kinetic assessment of injury risk factors in the lower extremity; (2) a comparison between a simple jump or landing test and a DT jump or landing test which included cognitive information. The risk of bias in the selected articles was analyzed using the recommendations of the Cochrane Collaboration. Of the 656 records identified, 13 met the established criteria. Additionally, two more articles were manually included after screening references from the included articles and previous related systematic reviews. Regarding the Risk of bias assessment, 12 studies did not surpass a score of 3 points (out of a total of 7). Only three studies exceeded a score of 3 points, with one article achieving a total score of 6. From the included studies, comparative conditions included actions influenced by the inclusion of a sports ball (n=6), performing tasks in virtual environments or with virtual feedback (n=2), participation in cognitive tasks (n=6), and tasks involving dual processes (n=7). The execution of decision-making (DM) during the jump-landing action resulted in biomechanical changes such as lower peak angles of hip flexion and knee flexion, along with increased vertical ground reaction force, knee abduction, and tibial internal rotation. Regarding limitations, discrepancies arise in defining what constitutes DT. As a result, it is possible that not all studies included in this review fit all conceptual definitions of DT. The inclusion of DT or constraints in jump-landing tests significantly alters biomechanical variables related to lower extremity injury risk in team sports. In future research, it would be beneficial to incorporate tasks into jumping tests that simulate the specific cognitive demands of team sports. This systematic review was registered in PROSPERO (registration number: CRD42023462102) and this research received no external funding.

Countermovement Jump and Isometric Strength Test–Retest Reliability in English Premier League Academy Football Players

Purpose: To examine the test–retest reliability of countermovement jump (CMJ) and isometric strength testing measures in elite-level under-18 and under-23 academy football players. Methods: A total of 36 players performed 3 maximal CMJs and isometric abductor (IABS), adductor (IADS), and posterior chain (IPCS) strength tests on 2 separate test days using dual force plates (CMJ and IPCS) and a portable strength testing device (IABS and IADS). Relative (intraclass correlation coefficient) and absolute (coefficient of variation, standard error of the measurement, and minimal detectable change [MDC%]) reliabilities for 34 CMJ, 10 IABS, 10 IADS, and 11 IPCS measures were analyzed using between-sessions best, mean, and within-session methods. Results: For all methods, relative reliability was good to excellent for all CMJ and all IADS measures and poor to good for all IABS and IPCS measures. Absolute reliability was good (ie, coefficient of variation &lt; 10%) for 27 (best) and 28 (mean) CMJ variables and for 6 (IABS and IADS) and 2 (IPCS) isometric measures. Commonly used CMJ measures (jump height, eccentric duration, and flight-time:contraction-time ratio) had good to excellent relative reliability and an MDC% range of 14.6% to 23.7%. Likewise, commonly used isometric peak force measures for IABS, IADS, and IPCS had good to excellent relative reliability and an MDC% range of 22.2% to 26.4%. Conclusions: Commonly used CMJ and isometric strength measures had good test–retest reliability but might be limited by their MDC%. Rate-of-force-development measures (for all isometric tests) and impulse measures (IPCS) are limited by poor relative and absolute reliability and high MDC%. MDC% statistics should be considered in the context of typical responsiveness.

Effects of Repeated Jump Testing and Diurnal Changes on Subsequent Countermovement Jump and Squat Jump Output and Force-Time Characteristics

Abstract Harrison, PW, James, LP, Jenkins, DG, Holmberg, PM, and Kelly, VG. Effects of repeated jump testing and diurnal changes on subsequent countermovement jump and squat jump output and force-time characteristics. J Strength Cond Res 38(1): 174–179, 2024—The aim of this brief study was to investigate the effects of repeated jump testing on performance over 2 consecutive days while considering the possibility of diurnal changes. Fourteen male subjects and 14 recreationally active female subjects completed countermovement jump (CMJ) and squat jump (SJ) testing on 5 occasions (baseline [0,800], 5 minutes [0,820], 8 hours [1,600], 24 hours [0,800], and 32 hours [1,600]) over 32 hours. An additional rested baseline test was conducted on a separate day in the afternoon (1,600) to compare jump performance between morning and afternoon baseline values. Excluding small decreases in CMJ height at 24 hours (p = 0.292, Cliff’s delta = −0.225) in male subjects and similar decreases in CMJ height at 5 minutes (p = 0.034, Cliff’s delta = −0.245) in addition to SJ height:contraction time at 32 hours (p = 0.126, Cliff’s delta = 0.153) in female subjects, findings generally showed no changes in jump performance over multiple assessments. Squat jump metrics may have showed small improvements between morning and afternoon baseline values in male subjects (SJ height:contraction time [p = 0.030, Cliff’s delta = 0.225]) and female subjects (SJ height [p = 0.013, Cliff’s delta = 0.173] and SJ height:contraction time [p = 0.091, Cliff’s delta = 0.163)]. As jump performance was largely unaffected by repeated jump testing, the present findings support the use of monitoring practices and research designs that require multiple jump assessments within acute periods (∼32 hours).

Estimating Muscle Fiber-Type Composition in Elite Athletes: A Survey on Current Practices and Perceived Merit.

To gather information on practices and perceptions of high-performance experts regarding their athletes' muscle fiber-type composition (MFTC) and its estimation. A questionnaire on the noninvasive versus invasive estimation of MFTC was completed by 446 experts including coaches and sport-science/sports-medicine staff. Moreover, the perceived importance of MFTC for training and performance optimization was assessed. Differences between sport types (individual and team sports) were analyzed using chi-square tests. Forty percent of the experts implemented MFTC assessment in pursuit of performance optimization, while 50% did not know their athletes' MFTC but expressed a desire to implement it if they would be able to assess MFTC. Ten percent did not perceive value in MFTC assessment. Only 18% of experts believed thattheir athletes would undergo a muscle biopsy, leading to the adoption of alternative noninvasive techniques. Experts primarily relied on their experience to estimate MFTC (65%), with experts working in individual sports using their experience more frequently than those working in team sports (68% vs 51%; P = .009). Jump tests emerged as the second-most commonly employed method for estimating MFTC (56%). When only considering experts who are currently using MFTC, 87% use MFTC to individualize training volume and 84% to individualize training intensity. Experts value MFTC assessment primarily to individualize training but mainly rely on noninvasive methods to estimate MFTC. Some of these methods lack scientific validity, suggesting a continuing need for education and further research in this area.

The Synergistic Effect of Muscle, Coordination, and Concentration on the Effectiveness of Jump Floating Serve: A Path Analysis Approach

The research addresses the low proficiency in executing jump floating serves among volleyball players, influenced by factors such as arm muscle explosive power, leg muscle explosive power, hand-eye coordination, and concentration. The study aimed to evaluate the impact of these factors on players' jump floating serve abilities. Using a quantitative approach and survey method, data were collected from 24 male volleyball players at Padang State University. The instruments included the jump floating serve test, One Hand Medicine Ball Put for arm muscle explosive power, Vertical Jump Test for leg muscle explosive power, ball throw response for hand-eye coordination, and Grid Concentration Test for concentration. Path analysis was utilized for data analysis. The results revealed: (1) a significant direct impact of arm muscle explosive power on jump floating serve ability (Py1= 0.358), (2) no significant direct impact of leg muscle explosive power on jump floating serve ability (Py2= 0.119), (3) a significant direct impact of hand-eye coordination on jump floating serve ability (Py3= 0.343), and (4) a significant direct impact of concentration on jump floating serve ability (Py4= 0.251). Additionally, there were no direct effects of arm muscle explosive power, leg muscle explosive power, or hand-eye coordination on concentration (P41= 0.043, P42= 0.242, P43= 0.427). However, indirect effects on jump floating serve ability through concentration were found for arm muscle explosive power (ꜫ1 = 0.090), leg muscle explosive power (ꜫ2 = 0.029), and hand-eye coordination (ꜫ3 = 0.107).

EFFECTS OF PHYSICAL AND COGNITIVE FACTORS ON REACTIVE AGILITY IN PROFESSIONAL FOOTBALL PLAYERS

Amaç: Bu çalışmanın birincil amacı futbolcularda fiziksel ve kognitif faktörlerin reaktif çeviklik üzerine etkisini incelemek; ikincil amacı ise futbolda alt ekstremite yaralanma riski düşük olan ve yüksek olan futbolcularda reaktif çeviklik parametrelerini karşılaştırmaktır. Yöntem: Çalışmaya 30 profesyonel futbol oyuncusu dahil edildi. Tüm katılımcılara fiziksel ve kognitif değerlendirmeler uygulandı. Reaktif çeviklik değerlendirmesinde görsel uyaran ve fotoselli kapılar içeren Reaktif Çeviklik Testi (RÇT) kullanıldı. Tablet temelli sağ/sol diskriminasyonu, Dikey Sıçrama Testi, T Çeviklik Testi (T-Test), Y Denge Testi (Y-Denge), 20 m Sprint Testi ve Hamstring Eksentrik Kuvveti değerlendirildi. Yaralanma risk analizi için ise Tuck Jump Testi kullanıldı. Sonuçlar: Çalışmamızda RÇT hareket süresi parametresi ile Y-Denge testi komposit, posteromedial ve posterolateral uzanma skoru ve sağ/sol diskriminasyonu doğruluk oranı arasında negatif yönde; T-Test ile pozitif yönde bir ilişki vardı (p

The Countermovement Rebound Jump: Between-Session Reliability and a Comparison With the Countermovement and Drop Jump Tests.

Xu, J, Turner, A, Comyns, TM, Chavda, S, and Bishop, C. The countermovement rebound jump: Between-session reliability and a comparison with the countermovement and drop jump tests. J Strength Cond Res 38(4): e150-e159, 2024-The countermovement jump (CMJ) and drop jump (DJ) are widely used jump tests to evaluate an athlete's neuromuscular performance. Nevertheless, conducting both the CMJ and the DJ assessments during one testing session can demand a considerable time investment that practitioners or coaches might not always have available. This study investigated whether the countermovement rebound jump (CMRJ) could be considered a viable alternative to the CMJ and DJ tests, respectively. Thirty-three physically active students volunteered as subjects (age: 27.2 ± 5.9 years, height: 1.78 ± 0.8 cm, body mass: 77.5 ± 11.5 kg), with 18 jumps completed for each subject across 2 testing sessions. The jump height (JH) and strategy-based metrics (time to take-off [TTTO], countermovement depth [CM depth], and reactive strength index [RSI] modified for CMJ and the first jump of the CMRJ; leg stiffness [ Kleg ], ground contact time [GCT], and RSI for DJ and the second jump for the CMRJ) were calculated simultaneously via the impulse-momentum, flight time, double integration, and motion capture methods. All variables were examined by repeated-measures analysis of variance, 2-way random effects model intraclass correlation coefficient (ICC), coefficient of variation (CV), and standard error of measurement, with the significance set at p ≤ 0.05. All 3 jump tests showed good-to-excellent relative reliability (ICC = 0.79-0.98) and good-to-moderate CV (≤9.83), with the only exception being Kleg measured during the DJ and in the second jump of the CMRJ assessment (CV ≤ 16.01%). Of all measured metrics, significant differences were only observed regarding TTTO between jumps ( p ≤ 0.027, effect size [ES] ≤ 0.49). The comparison of calculation methods indicated that the JH calculated by 4 methods were not significantly different between jump actions ( p ≥ 0.254). These findings support the use of the CMRJ as a reliable alternative to the CMJ and DJ tests. However, practitioners should be mindful of using Kleg as a metric, whereas practitioners are also advised to allocate sufficient familiarization trials before implementing the CMRJ into their routine test batteries.

Adenosine and its derivatives improve exercise performance and exert anti-fatigue effects via AMPK/PGC-1α signaling pathway in mice

Studies of the AMPK/PGC-1α signaling pathway and exercise-induced metabolism have facilitated the development of anti-fatigue agents and exercise mimetics. In this work, adenosine and its 22 derivatives, typical of substitutions at the hydroxyl group of the sugar moiety, were firstly evaluated as anti-fatigue agents. In the running wheel tests, adenosine and most derivatives demonstrated a significant increase in the exhaustion distance when compared to the control group. Particularly, the optimized compound 2 exhibited a 3.1-fold increase in exhaustion distance compared to the positive control group treated with AICAR, and a remarkable 9.8-fold increase compared to the blank control group. Furthermore, improved performances were observed in weight-loaded swimming, high jumping, hanging wire, and tail suspension tests. Compound 2 not only reduced levels of lactic acid (LA) and blood urea nitrogen (BUN), but also preserved hepatic and muscle glycogen content during exercise. Notably, compound 2 activated AMPK/PGC-1α pathway without stimulating the central nervous system. Moreover, compound 2 demonstrated a favorable safety in vivo at a dose of 1.96 × 10-5 mol/kg for 21 days. This study unveils, for the first time, the ability of adenosine and its derivatives to resist exercise-induced fatigue, thereby providing promising lead compounds for the development of drugs aimed to prevent and treat fatigue-related diseases. Moreover, it sheds light on the potential therapeutic approaches utilizing endogenous substance.

Tests for Jumps in Yield Spreads

This article studies high-frequency econometric methods to test for a jump in the spread of bond yields. We propose a coherent inference procedure that detects a jump in the yield spread only if at least one of the two underlying bonds displays a jump. Ignoring this inherent connection by basing inference only on a univariate jump test applied to the spread tends to overestimate the number of jumps in yield spreads and puts the coherence of test results at risk. We formalize the statistical approach in the context of an intersection union test in multiple testing. We document the relevance of coherent tests and their practicability via simulations and real data examples.

The Correlational Study of the Vertical Jump Test and Wingate Cycle Test as a Method to Assess Anaerobic Power in Road Cyclists

Road Cycling is an important sport that uses anaerobic and aerobic metabolism and especially sprinter cyclists have higher anaerobic capacity. The assessment of anaerobic power in cyclists often involves the use of the vertical jump and Wingate cycle tests. The lack of research in the field of cycling-specific tests to assess anaerobic performance has led to the improvement of existing research. The objective of this research was to investigate the correlation between the vertical jump test and the Wingate anaerobic cycling tests, both of which are often used to assess anaerobic power in road cyclists. A correlation study was conducted on 15 athletes of the Turkish national road cycling team in the 14-16 age group (15.107 ± 0.717 (SD)). The sample of the study was determined by using the convenient sampling method. On the first day, anthropometric measurements and the vertical jump test were conducted. The Wingate cycle ergometer test, lasting for a duration of 30 seconds, was administered to the participants on the second day. The computer application was used to determine the 30-second peak and average anaerobic power during the test. The results acquired from the study revealed a statistically significant positive relationship between the vertical jump performance and the peak power production measured during the Wingate cycle test (r=0.321, p&amp;lt;0.05). The findings indicate that vertical jump tests may serve as suitable field measurements of anaerobic power for road cyclists, as an alternative to the laboratory-based Wingate anaerobic test.