Reliability, Usefulness, and Validity of a Repeated Sprint and Jump Ability Test

Transcription

1 ORIGINAL INVESTIGATIONS International Journal of Sports Physiology and Performance, 2010, 5, 3-17 Human Kinetics, Inc. Reliability, Usefulness, and Validity of a Repeated Sprint and Jump Ability Test Martin Buchheit, Matt Spencer, and Said Ahmaidi Purpose: Two studies involving 122 handball players were conducted to assess the reliability, usefulness, and validity of a repeated shuttle-sprint and jump ability (RSSJA) test. The test consisted of 6 ( m) sprints departing on 25 s, with a countermovement jump performed during recovery between sprints. Methods: For the reliability and usefulness study, 14 well-trained male handball players performed the RSSJA test 7 d apart. Reliability of the test variables was assessed by the typical error of measurement, expressed as a coefficient of variation (CV). The minimal changes likely to be real in sprint time and jump power were also calculated. For the validity study, players of seven s (national to international levels, women and men) performed the RSSJA test. Results: CV values for best and mean sprint time were 1.0% (90% CL, 0.7 to 1.6) and 1.0% (90% CL, 0.7 to 1.4). CV values for best and mean jump peak power were 1.7% (90% CL, 1.2 to 2.7) and 1.5% (90% CL, 1.1 to 2.5). The percent sprint and jump decrements were less reliable, with CVs of 22.3% (90% CL, 15.7 to 38.3) and 34.8% (90% CL, 24.2 to 61.8). Minimal changes likely to be real for mean sprint time and jumping peak power were 2.6% and 4.8%. Qualitative analysis revealed that the majority of between- differences were rated as almost certain (ie, 100% probability that the true differences were meaningful) for mean sprint and jump performances. Conclusion: The RSSJA test is reliable and valid to assess repeated explosive effort sequences in sports such as handball. Test results are likely to be representative of gender and competition level; thus the test could be used to discriminate across playing standards and monitor fitness levels. Keywords: handball, speed testing, jumping ability, agility, repeated efforts sequence In sports such as basketball, handball, or netball, players have to repeat sequences of short explosive efforts, such as sprints (<15 m) with frequent changes in direction 1 4 followed by maximal jumping movements. Furthermore, planned jumps occur predominantly after high-intensity runs, such as throwing in the air after a fast strike in handball. 2 In addition, repeated sprint ability has been shown to be associated Buchheit is with the Laboratory of Exercise Physiology and Rehabilitation, Faculty of Sport Sciences, University of Picardie, Jules Verne, Amiens, France. Spencer is with Jerv Football Club, Grimstad, Norway. Ahmaidi is with the Laboratory of Exercise Physiology and Rehabilitation, Faculty of Sport Sciences, University of Picardie, Jules Verne, Amiens, France. 3

2 4 Buchheit, Spencer, and Ahmaidi to actual match performance 5 and competitive level of play. 6 Vertical jump height/ power has also been considered a relevant performance index in sports 7 and is thus considered as a discriminating variable of different competitive standard. 8 Relatively few studies have evaluated repeated sprint ability in the field, 9 12 while assessment of jump ability is generally only investigated as an isolated quality. 8,13 Although assessment of repeated sprint and jump abilities have previously been integrated, 14 the assessment of repeated effort sequences, specific of sports, has been poorly investigated and has been restricted to volleyball-specific movements. 4 Thus, to integrate the explosive effort sequences to simultaneously assess repeated sprint and jump abilities, we proposed 15 to add a universal countermovement jump during the recovery phase (within 3 s following the preceding sprint) of a commonly used shuttle-based repeated sprint ability test. 6,10 While examining the effect of different training regimens on performance of this test in young elite women handball players, we observed relative changes in repeated jump ability to be significantly higher than those in single jumping, single sprinting, and repeated sprint abilities. 15 This suggested that repeated jump ability, especially when jumps are performed immediately after maximal sprints, such as in real games, might be a highly sensitive measure to track changes in athletic performance following a training period. 15 Despite these encouraging results, 15 investigating the reliability and validity of the test was still warranted. Moreover, extending the practicability of the test to confidently monitor the progression of a player, which is generally defined as the test usefulness, was also required to increase the relevance the test. Hopkins 16 has proposed to compare the magnitude of the smallest worthwhile change in performance with the uncertainty or noise in the test result. Knowledge of the minimal change in performance likely to be real 17 has also been shown to be of great importance in a training perspective. While over-ground repeated sprint ability tests have been shown to discriminate soccer players performance across different ages and levels of competition, 6,18 it is not known whether the repeated sprint and jump test is also likely to differentiate handball players of various age, gender, and competitive play of a similar extent. Normative data are not yet available for this test, which might be of great interest for the development of talent selection and recruitment purposes. The aim of this study was thus to (1) investigate the reliability of this repeated shuttle-sprint and jump ability test, (2) determine its usefulness and practicality in the field to monitor the progression of an athlete, and (3) examine its construct validity, that is, whether repeated sprinting and jumping performances are representative of age, gender, and competitive play level. Subjects and Study Design Methods One hundred twenty-two players from four women s and three men s French handball s participated in the study (Table 1). Their maturational status was estimated via self-assessment questionnaires administrated by an experienced investigator. 19 Training details, such as weekly training hours, were also collected. All subjects played at a competitive level, from national leagues to international levels. Fourteen players from a competing in the 5th French male league

3 Repeated Sprint and Jump Ability Test 5 participated in both the reliability and construct validity study, whereas all other athletes participated in the second study only. After one familiarization trial the preceding week, 20 all tests were performed at the end of the preparatory phase, 1 wk before the start of the competitive season. All tests were preceded by a standardized warm-up including athletic drills and accelerations, which was terminated with a single sprint-jump sequence performed at maximal intensity. Testing began 2 min 30 s after this last effort, which was used as the players reference performance. The players involved in the reliability study performed the test twice, separated by 7 d. The sample size used in the reliability study was consistent with that used in previous reliability studies in the field. 11,20 All players were provided with the procedures and risks associated with participation in the study and gave their written informed consent before participation. The study was approved by the university s human research ethics committee. Repeated Shuttle-Sprint and Jump Ability Test (RSSJA). The RSSJA was designed to simulate the repeated explosive efforts commonly performed in sports. 1 3 To compare athletic profiles of players of different sports on a single protocol, we chose a test that used common sprinting distances and 180 changes of direction, as well as a universal countermovement jump (CMJ). The test consisted of six maximal m shuttle sprints ( 5 s) departing every 25 s. During the 20-s recovery between sprints, subjects had to decelerate, perform a CMJ, and then an active recovery (covering 36 m running at 2.1 m s 1 ; Figure 1). Since an arm swing may complicate comparisons between pre- and posttraining blocks, due to a change in upper body strength affecting the contribution of arm swing to CMJ performance, participants were ask to keep their hands on their hips during all jumps. The standardization of arm position during jumping is obviously important for test reliability. The depth of the countermovement jumps were self-selected to minimize intervention and thereby maximize the potential application to practical settings where time limitations may exist. Moreover, it is apparent that any change in countermovement depth does not influence jumping height. 21 All athletes were verbally encouraged throughout the test and asked to jump as high as possible. Two seconds before starting each sprint, the subjects were asked to assume the ready position (ie, center of gravity up to the front foot, placed 5 cm before the first timing gate) and await the start signal from a compact disc. 10 The best sprint time (RS best ; s) and jump height (RJ best ; cm), the mean sprint time (RS mean ; s), and jump height (RJ mean ; cm) were calculated. Peak power during CMJ was also calculated according to the following formula, which has been shown to be the most accurate to estimate peak power from jumping height, in both women and men: 22 CMJ (W) = (60.7 h [cm]) + (45.3 m [kg]) The percent sprint time (RS dec ; %) and percent jump height or peak power (RJ dec ; %) decrement were calculated, respectively, as ((mean sprint time / best sprint time 100) 100) and (100 (mean jump / best jump 100)). Sprinting times were recorded with photoelectric cells (Wireless Timing Radio Controlled, Brower Timing System, Colorado, USA), and jumping height with an Optojump (Microgate, Bolzano, Italy). 10 Statistical Analysis. The distribution of each variable was examined with the Shapiro-Wilk normality tests. Homogeneity of variance was verified by a Levene test, and data herein are presented as means and standard deviations (± SD). To examine the reliability of the test over the two consecutive trials, pairwise

4 Table 1 Subject characteristics Group n Age (y) Tanner stage Stature (cm) Weight (kg) Training practice (h wk 1 ) Regional elite young women s ± 1.1 III = 1, IV = 13, V = ± ± Women s French national under 16 yr ± 0.6 III = 5, IV = 22, V = ± ± Women s French national under 18 yr ± 0.5 III = 3, IV = 13, V = ± ± Women s 2nd league ± 5.1 IV = 2, V = ± ± Regional elite young men s ± 1.1 III = 3, IV = 8, V = ± ± Men s 5th league ± 4.2 IV = 1, V = ± ± Men s 2nd league ± 4.7 IV = 1, V = ± ± Note. Values are mean ±SD. Age, pubertal development (Tanner stage), anthropometric parameters, and training practice of athletes playing for the seven s. 6

5 Repeated Sprint and Jump Ability Test 7 Figure 1 Schematic of the shuttle sprint- and jump-based repeated effort ability test. comparisons were first applied to determine any learning effect or systematic bias with paired t test. The magnitude of differences between consecutive trials was also expressed as standardized mean difference (Cohen effect sizes, ES). The criteria to interpret the magnitude of the ES were as follows: <0.2 trivial, 0.2 to 0.5 small, 0.5 to 0.8 moderate, >0.8 large. 23 The spreadsheet of Hopkins 24 was also used to determine the change in the mean between trials and the typical error of measurement (TE, s or cm), expressed as a coefficient of variation (CV, %). Numerous earlier studies have reported biomechanical variables with CVs below 5% as reliable. 9,11 13 It is important to acknowledge that having the best reliability does not mean a variable is the most useful at measuring something valuable, as a number of physiological measures have high reliability but some are not sensitive measurement tools. 23 As a result, a CV <5% was set as the criterion to declare a variable as reliable. The usefulness of the test was assessed while comparing the SWC (0.2 multiplied by the between-subject deviation, based on Cohen s effect size principle) with the typical error. 23 If the typical error was below the SWC, the test was rated as good ; if the typical error was similar to the SWC, the rating was OK ; and if the typical error was higher that the SWC, a rating of marginal was given. 16 The smallest difference needed to be considered real (MD, corresponding to a change likely to be almost certain ) was calculated as TE To examine the construct validity of the test, possible differences in the reliable parameters of the various playing levels were assessed with a one-way ANOVA ( factor with seven levels). When a significant main effect was identified, a Tukey post hoc test was used to further delineate differences between s (Minitab 14.1 Software, Minitab Inc, Paris, France). For all analyses, the level of significance was set at P < In addition to this null-hypothesis testing, s performance were also assessed for clinical significance using an approach based on the magnitudes of differences. 25 Between- differences in mean sprint times and jumping peak powers were thus assessed using 90% confidence limits and the chance that the true (unknown) values for a given were better or poorer than these for the six

6 8 Buchheit, Spencer, and Ahmaidi other s was calculated. 25 The quantitative chances for a of having better or poorer performance were assessed qualitatively as follows: <1%, almost certainly not; 1% to 5%, very unlikely; 5% to 25%, unlikely; 25% to 75%, possible; 75% to 95%, likely; 95 to 99, very likely; >99%, almost certain. If the chance of having better and poorer performances were both >5%, the true difference was assessed as unclear. For all pairwise comparisons, thresholds for clinical differences were calculated as 0.2 the pooled SD of the two groups of interest. Results Maximal Effort at the Start of the Repeated Sequences Best sprint time and jump height recorded during the RSSJA test were ± 1.8% and 98.9 ± 2.2% of the reference performances undertaken once before the test, respectively. There was also no significant difference between performances during the test and the reference trial (P =.39 and.26 for best sprint time and jump height, respectively). Short-Term Reliability The pairwise analysis revealed no significant differences between the two trials (all P >.05), regardless of the performance variable assessed. Differences in all indices between repeated trials displayed trivial ES. All other reliability variables are presented in Table 2. Values for TE and CV were low for best and mean sprint time and jump height/power. Conversely, percent sprint and jump decrements displayed very high CV values (>20%). Coefficients of variation were consistently lower for jumping ability when expressed in watts compared with centimeters. Test Usefulness Changes in performance likely to be real are presented in Table 2. Construct Validity Since %Dec measures displayed poor reliability for both sprint and jump performance, this variable was not used in the construct validity analysis. Figures 2 and 3 illustrate sprint and jump performance of the test in the seven different s. The one-way ANOVA revealed a significant effect (all P <.001), with s ranked in the expected order. Between- differences highlighted by the post hoc analysis are given in Figures 2 and 3. Magnitude-based inferences for differences between s/levels in mean sprint times and peak jumping power are presented in Tables 3 and 4, respectively. The qualitative analysis revealed that all between- differences were rated as almost certain for mean sprint times, with the exception of the Women s 2nd league vs the Regional elite young men s comparison (Table 3). Furthermore, all between- differences were rated as almost certain for mean peak jumping power, with the exception of the Women s 2nd league vs Women s French national under 18 yr and Regional elite young men s vs Men s 5th league comparisons, where differences were unclear (Table 4).

7 Table 2 Measures of reliability for repeated sprints and jumps during the RSSJA test in the 5th French men s handball league RS best RS mean RS %Dec RJ best RJ mean RJ %Dec Height Power Height Power Height Power TE (90% CL) 0.05 s ( ) 0.05 s ( ) 0.61% ( ) 1 cm ( ) 58 W (42 94) 0.9 cm ( ) 55 W (40 89) 2.0% ( ) 1.6% ( ) CV (90% CL) 1.0% ( ) 1.0% ( ) 22.3% ( ) 2.9% ( ) 1.7% ( ) 2.9% ( ) 1.5% ( ) 21.2% ( ) 34.8% ( ) Difference (90% CL) 0.05 s ( ) 0.02 s ( ) 0.48% ( ) 0.5 cm ( ) 32 W ( 72 16) 1.4 cm ( 2.1 to 0.6) 82 W ( ) 0.2% ( ) 0.1% ( 1.5 to 1.2) ES (rating) SWC (%) (test rating) 0.05 s (1.1%) (OK) 0.05 s (1.0%) (OK) 0.22% (8.9%) (marginal) 0.9 cm (2.8%) (OK) 131 W (3.8%) (good) 0.9 cm (3.5%) (good) 125 W (3.9%) (good) 0.7% (6.4%) (marginal) 0.5% (8.1%) (marginal) MD 0.13 s ( 2.63%) 0.13 s ( 2.63%) 1.68% ( 45.5%) +2.7 cm (+7.9%) +161 W (+4.6%) +2.5 cm (+8.5%) +153 W (+4.8%) 5.8% ( 48.4%) 4.5% ( 63.8%) Note. Typical error of measurement (TE), TE expressed as a coefficient of variation (CV), difference in mean between the two trial, effect size (ES) and ES rating (see Methods), smallest worthwhile change (SWC) and rating of the test (see Methods), minimal difference needed to be considered as real (MD) calculated for best sprint time (RS best ; s) and jump height (RJ best ; centimeters and watts), mean sprint time (RS mean ; s) and jump height (RJ mean ; centimeters and watts), and percent sprint time (RS %Dec ; %) and jump height (RS %Dec ; %) decrement. 9

8 10 Buchheit, Spencer, and Ahmaidi Figure 2 Best (RS b ) and mean (RS m ) sprint times for athletes playing in the seven different s. (a) Significant difference (P <.05) vs Women s French national U-16, (b) vs Women s French national U-18, (c) vs Women s 2nd league, (d) vs Regional elite young mean, (e) Men s 5th league, and (f) Men s 2nd league. Values are mean ± SD. Discussion The main findings of the current study reveal that best and mean sprinting and jumping performances during RSSJA showed good reliability, whereas the decrement scores showed poor reliability. Regarding the usefulness of this test to monitor the progression of an athlete, we estimated that performance improvements of at least 2.6% and 4.8% in mean sprint time and estimated jump peak power have to be detected to attain an almost certain beneficial increase in performance. Moreover, the test showed construct validity since test results were representative of gender and competitive play level. Test Reliability The reliability of the repeated shuttle-sprint and jump ability test was very good with the absence of any systematic bias (ie, the between-test differences were rated as trivial based on effect size calculation) and CV values approximately 1.0% for sprints. The CV for mean repeated sprint performance was similar to that reported previously (0.7%, %, 9 and 2.4% 4 ). This confirms that jumping during recovery has no likely adverse effect on repeated sprint reliability. 4 The current study

9 Repeated Sprint and Jump Ability Test 11 Figure 3 Best (RJ b ) and mean (RJ m ) jumping power (W) for athletes playing in the seven different s. (a) Significant difference (P <.05) vs Women s French national U-16, (b) vs Women s French national U-18, (c) vs Women s 2nd league, (d) vs Regional elite young mean, (e) Men s 5th league, and (f) Men s 2nd league. Values are mean ± SD. examined, for the first time, the reliability of repeated countermovement jumping performance, when conducted immediately after maximal sprints with changes of directions as is evident during competition. 1 3 A learning effect was not apparent for best and mean jumping height, but CV values (3%) tended to be slightly higher than for sprint performance. Conversely, estimated peak power values led to lower CV values (1.5% for mean CMJ peak power), which were similar to those of repeated sprints. This apparent higher reproducibility of peak power compared with jumping height was in fact related to the subject s body mass, which is used as a constant in peak power calculation 22 and is not likely to change considerably between measurements. Thus, the lower CV observed for power values does not account for an accurate lower error of measurement and it is more likely that the ability to detect change relative to the random error is approximately the same in both instances. Since jumping height and peak power are two measures commonly used in the field to assess jumping capacities, we intended to provide CV and normative values for both measurements. Nevertheless, CV values in the current study were slightly higher than those reported for repeated countermovement jumps without prior sprints (1.9%) 13 or for a volleyball-specific test in elite Australian players (0.5%). 4 We can hypothesize that the subjects training background, sporting activity, explosive efforts sequence type, or jump height measurement device might

10 Table 3 Magnitude-based inferences for mean differences in mean sprint time as a function of gender, age, and playing level Regional elite young women s Women s French national under 16 y Women s French national under 18 y Women s 2nd league Regional elite young men s Men s 5th league Men s 2nd league Regional elite young women s 5.1% ( 7.3, 2.7) 8.1% ( 10.4, 5.8) 12.2% ( 15, 9.3) 12.8% ( 15.1, 10.4) 14.3% ( 16.3, 12.2) 17.8% ( 19.8, 15.8) Women s French national under 16 y 3.2% ( 5.5, 0.9) 0/5/94 7.5% ( 10.3, 4.6) 8.1% ( 10.5, 5.7) 9.7% ( 11.7, 7.6) 13.4% ( 15.3, 11.4) Women s French national under 18 y 4.4% ( 7.4, 1.3) 0/4/96 5.1% ( 7.6, 2.5) 0/1/99 6.7% ( 8.8, 4.5) 10.5% ( 12.6, 8.4) Women s 2nd league 0.7% ( 3.9, 2.7) 19/39/42 2.4% ( 5.3, 0.7) 4/18/78 6.4% ( 9.2, 3.5) Regional elite young men s 1.7% ( 4.2, 0.9) 5/23/72 5.8% ( 8.2, 3.3) Men s 5th league 4.1% ( 6.2, 2.0) 0/1/99 Note. Values represent mean difference (90% CL) and percentage chance of having better/trivial/poorer values than the other s obtained from qualitative analysis. 12

11 Table 4 Magnitude-based inferences for mean differences in mean peak jumping power as a function of gender, age, and playing level Regional elite young women s Women s French national under 16 y Women s French national under 18 y Women s 2nd league Regional elite young men s Men s 5th league Men s 2nd league Regional elite young women s 9.3% ( 15.8, 2.2) 0/6/ % ( 20.8, 7.3) 0/1/ % ( 21.3, 6.7) 0/1/ % ( 34.0, 19.9) 31.2% ( 36.8, 25.0) 43.9% ( 47.9, 39.7) Women s French national under 16 y 5.5% ( 11.8, 1.3) 2/23/75 5.5% ( 12.6, 2) 4/23/ % ( 26.7, 12.3) 24.1% ( 29.7, 18.0) 38.2% ( 41.9, 34.2) Women s French national under 18 y 0.1% ( 7.8, 8.4) 28/44/ % ( 22.7, 6.9) 0/1/ % ( 25.9, 12.9) 34.6% ( 38.8, 30.1) Women s 2nd league 15.1% ( 23.1, 6.4) 0/1/ % ( 26.4, 12.3) 34.6% ( 39.3, 29.5) Regional elite young men s 5.3% ( 14.2, 4.4) 7/27/ % ( 29.4, 15.8) Men s 5th league 18.6% ( 24.5, 12.2) Note. Values represent mean difference (90% CL) and percentage chance of having better/trivial/poorer values than the other s obtained from qualitative analysis. 13

12 14 Buchheit, Spencer, and Ahmaidi explain these slight differences. Even though the use of a force plate would have been more precise to measure jumping power, 14 we believe that the methodology used here to measure jumping height via any field device (eg, Optojump, vertex, yardstick, or contact matt, and valid conversion equations for both genders 22 ) is more accessible and affordable in the field for coaches and trainers. The poor reliability of performance decrement in mean sprinting times and jumping power were comparable to sprint data reported previously (14.9% 11 and 30.2% 9 ). The current study also shows for the first time that the reliability of repeated jump decrement is poor, regardless of the measure used (ie, height vs power). Finally, the sample size used here to assess the reliability of the test could be considered as small. 23 However, the fact that we found good reliability suggests that increasing the sample size would not have had a much greater effect on the results. Test Usefulness Because typical error was not higher than that calculated for the smallest worthwhile change, the usefulness of the test was rated as OK and good for best and mean sprint time and jump height (Table 2). From a practical viewpoint, to ascertain meaningful or almost certain changes in performance, it is therefore suggested that a performance improvement of at least 2.6% ( 0.13 s) and 4.8% (+153 W), or 8.5% (+2.5 cm), in mean sprint time and jump peak power (or height) have to be detected to attain a real 17 increase in performance. Calculation of this minimal difference needed to be real can be considered as very conservative compared with other approaches. 16 Nevertheless, interpreting changes in performance based on smaller threshold values, as the smallest worthwhile change, for example half of a CV or TE 2, would require the use of specifically designed spreadsheets, which may be impractical in the field setting. We thus propose to provide coaches with thresholds that were almost certain (approximately 100%) to be representative of a true change/difference in performance. The calculated minimal values in the current study are consistent with the magnitude of changes in repeated shuttle-sprint performance observed after a short training period in elite junior soccer ( 2.2% 9 ), elite adolescents ( 2.0% 10 and 3.9% 26 ) and adult handball ( 2.8% 27 ) players. Conversely, in accordance with Spencer, 11 percent decrement of sprint (and jump) were likely to be worthless. The test was rated as marginal for this index, because of the considerable noise within this measurement variable. Test Validity As expected, the younger women playing at the lower handball level displayed significantly and almost certainly the lowest repeated sprint (Figure 2 and Table 3) and jumping (Figure 3 and Table 4) abilities when compared with the women s s of a higher level and all of the men s s. Conversely, the adult men playing in the highest league had significantly and almost certainly the best performances when compared with all other s. The fact that magnitude-based inferences showed meaningful differences in performance between almost all s (Table 3 and 4), but not the ANOVA and post hoc analyses (Figure 2 and 3), confirms that a null-hypothesis-based approach might be too conservative and is not likely to be the best method to assess differences in performance in sport science. 25,28 Even though the current study is the first to report measures of overall repeated

13 Repeated Sprint and Jump Ability Test 15 explosive sequences in sport players of different age, gender, and competitive play levels, the present data are in accordance with previous observations that have shown strength, (repeated) speed, power, and aerobic qualities to differ between gender and competitive levels in handball, 29 volleyball, 4 basketball, 30 and soccer. 6,8 For instance, Mujika et al 8 reported age- and gender-specific differences in performance on several explosiveness-related field tests such as vertical jump, 15-m sprint time, or agility test, with younger women tending to display the worst performance. Furthermore, professional Italian soccer players have been shown to have better repeated sprint performance than amateur players. 6 Similar results were also reported by Abrantes et al, 18 using Bangsbö s repeated sprints test (ie, m, departing every 25 s) that clearly discriminated Portuguese elite, regional adults, junior, and adolescent soccer players. In the only study that measured the ability to repeat explosive efforts, Sheppard et al 4 showed that Australian national players have higher and faster performances than players from the development national. In summary, the present findings support the general view that an athlete s ability to repeat explosive efforts is related to general fitness level, partly attributable to gender, natural ability, training history, and maturation process. Finally, performing repeated-shuttle runs might be considered as extreme changes of directions, when compared with those commonly observed in the field. Furthermore, performing countermovement jumps may not best represent the jumping patterns during games. However, the intension of this test is that it is generic and can be used to compare the athletic profiles of relevant sports. Compared with a sport-specific test (eg, Sheppard et al 4 ), the RSSJA test involves standard and common running distances, changes of directions, and jumping movements so that players from different sports can easily cope with the protocol. While the present findings support the construct validity of the RSSJA test for handball players, investigating players from other sports such as basketball or netball at different playing levels would elaborate on the construct validity of the test. Practical Applications and Conclusions The RSSJA test is reliable and valid to assess repeated explosive effort sequences (ie, repeated sprint and jump abilities simultaneously) in sports such as handball. Owing to the low typical errors of measurement, the RSSJA test is appropriate to monitor changes in an athlete s sprinting and jumping performance throughout a season. It is suggested that a performance improvement of at least 2.6% ( 0.13 s) and 4.8% (+153 W) in mean sprint time and estimated jump peak power have to be detected to determine an almost certain increase in performance. In addition, since test results are likely to be representative of gender and playing level, the use of the test in talent identification purposes is also of interest. Acknowledgments The authors thank Irmant Cadjjiov for his assistance with manuscript preparation and the subjects for their enthusiastic participation. We also thank Pierre Mangin, head coach of the Women s French national handball, and Christine Renaud, Arnaud Parisy, and Francois Berthier for their support during the experimentations.

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