Reliability and validity of a new repeated Agility test as a measure of anaerobic and Explosive power

Research Unit, School and University Sportive Practices and Performance, Higher Institute of Sports and Physical Education, Kef, Tunisia.
The Journal of Strength and Conditioning Research (Impact Factor: 2.08). 02/2011; 25(2):472-80. DOI: 10.1519/JSC.0b013e3182018186
Source: PubMed


The aim of this study was to evaluate the reliability and validity of a repeated modified agility test (RMAT) to assess anaerobic power and explosiveness. Twenty-seven subjects (age: 20.2 ± 0.9 years, body mass: 66.1 ± 6.0 kg, height: 176 ± 6 cm, and body fat: 11.4 ± 2.6%) participated in this study. After familiarization, subjects completed the RMAT consisting of 10 × 20-m maximal running performances (moving in forward, lateral, and backward) with ~25-second recovery between each run. Ten subjects performed the RMAT twice separated by at least 48 hours to evaluate relative and absolute reliability and usefulness of the test. The criterion validity of the RMAT was determined by examining the relationship between RMAT indices and the Wingate anaerobic test (WAT) performances and both vertical and horizontal jumps. Reliability of the total time (TT) and peak time (PT) of the RMAT was very good, with intraclass correlation coefficient > 0.90 and SEM < 5% and low bias. The usefulness of TT and PT of the RMAT was rated as "good" and "OK," respectively. The TT of the RMAT had significant correlations with the WAT (peak power: r = -0.44; mean power: r = -0.72), vertical jumps (squat jump: r = -0.50; countermovement jump: r = -0.61; drop jump (DJ): r = -0.55; DJ with dominant leg: r = -0.72; DJ with nondominant leg: r = -0.53) and 5 jump test (r = -0.56). These findings suggest that the RMAT is a reliable and valid test for assessing anaerobic power and explosiveness in multisprint sport athletes. Consequently, the RMAT is an easily applied, inexpensive field test and can provide coaches and strength and conditioning professionals with relevant information concerning the choice and the efficacy of training programs.

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Available from: Zied Gharbi, Jan 11, 2014
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    • "In this context, in order to perform successfully, team sport players need to be good movers in different directions, and often, in confined spaces [5]. Thus, improving the change of direction speed (CODS) of soccer players has become a focus of training programmes and consequently, many studies have been conducted to enhance and assess this athletic quality [6], [7]. "
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    ABSTRACT: Agility is a determinant component in soccer performance. This study aimed to evaluate the reliability and sensitivity of a "Modified Illinois change of direction test" (MICODT) in ninety-five U-14 soccer players. A total of 95 U-14 soccer players (mean ± SD: age: 13.61±1.04 years; body mass: 30.52±4.54 kg; height: 1.57±0.1 m) from a professional and semi-professional soccer academy, participated to this study. Sixty of them took part in reliability analysis and thirty-two in sensitivity analysis. The intraclass correlation coefficient (ICC) that aims to assess relative reliability of the MICODT was of 0.99, and its standard error of measurement (SEM) for absolute reliability was <5% (1.24%). The MICODT's capacity to detect change is "good", it's SEM (0.10 s) was ≤ SWC (0.33 s). The MICODT is significantly correlated to the Illinois change of direction speed test (ICODT) (r = 0.77; p<0.0001). The ICODT's MDC95 (0.64 s) was twice about the MICODT's MDC95 (0.28 s), indicating that MICODT presents better ability to detect true changes than ICODT. The MICODT provided good sensitivity since elite U-14 soccer players were better than non-elite one on MICODT (p = 0.005; dz = 1.01 [large]). This was supported by an area under the ROC curve of 0.77 (CI 95%, 0.59 to 0.89, p<0.0008). The difference observed in these two groups in ICODT was not statistically significant (p = 0.14; dz = 0.51 [small]), showing poor discriminant ability. MICODT can be considered as more suitable protocol for assessing agility performance level than ICODT in U-14 soccer players.
    PLoS ONE 04/2014; 9(4):e95773. DOI:10.1371/journal.pone.0095773 · 3.23 Impact Factor
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    • "In the last decade, it has been widely regarded that repeated sprint ability (RSA) is considered a relevant fitness component in team sports (Buchheit et al., 2010a; Buchheit et al., 2010b; Castagna et al., 2007). In this context, a various range of testing protocols were used to either evaluate RSA (Haj-Sassi et al., 2011; Spencer et al., 2011), or as a tool of training program prescription (Buchheit et al., 2010c). Nevertheless, fitness attributes and energetic requirements of RSA are still a subject of debate among researchers and fitness coaches (Gaitanos et al., 1993; Spencer et al., 2011). "
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    ABSTRACT: The aims of this study were firstly, to examine the relationship between repeated sprint performance indices and anaerobic speed reserve (AnSR), aerobic fitness and anaerobic power and secondly, to identify the best predictors of sprinting ability among these parameters. Twenty nine subjects (age: 22.5 ± 1.6 years, body height: 1.8 ± 0.1 m, body mass: 68.8 ± 8.5 kg, body mass index (BMI): 22.2 ± 2.1 kg•m-2, fat mass: 11.3 ± 2.9 %) participated in this study. All participants performed a 30 m sprint test (T30) from which we calculated the maximal anaerobic speed (MAnS), vertical and horizontal jumps, 20m multi-stage shuttle run test (MSRT) and repeated sprint test (10 × 15 m shuttle run). AnSR was calculated as the difference between MAnS and the maximal speed reached in the MSRT. Blood lactate sampling was performed 3 min after the RSA protocol. There was no significant correlation between repeated sprint indices (total time (TT); peak time (PT), fatigue index (FI)) and both estimated VO2max and vertical jump performance). TT and PT were significantly correlated with T30 (r=0.63, p=0.001 and r=0.62, p=0.001; respectively), horizontal jump performance (r = -0.47, p = 0.001 and r = -0.49, p = 0.006; respectively) and AnSR (r=-0.68, p= 0.001 and r=-0.70, p=0.001, respectively). Significant correlations were found between blood lactate concentration and TT, PT, and AnSR (r=-0.44, p=0.017; r=-0.43, p=0.018 and r=0.44, p=0.016; respectively). Stepwise multiple regression analyses demonstrated that AnSR was the only significant predictor of the TT and PT, explaining 47% and 50% of the shared variance, respectively. Our findings are of particular interest for coaches and fitness trainers in order to predict repeated sprint performance by using AnSR that can easily identify the respective upper performance limits supported by aerobic and anaerobic power of a player involved in multi-sprint team sports.
    Journal of Human Kinetics 03/2014; 40(1):139-48. DOI:10.2478/hukin-2014-0016 · 1.03 Impact Factor
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    ABSTRACT: INTRODUCTION Although talent identification has been a popular topic in science and soccer, there is no consensus whether future success can be predicted by physiological tests at an early age (Le Gall et al., 2010; Williams & Reilly, 2000). For this reason, the purpose of the following study was to compare physiological characteristics among 14- to 17-year-old pre-selected soccer players in terms of subsequent career success. METHOD In 2001, the Austrian Football Association, the Department of Sport Science (University of Salzburg) and the IMSB (Vienna) launched a project targeting the development of talented soccer players who attended youth soccer academies throughout Austria. Since then, approximately 5,000 players ranging in age from 13 to 18 years were measured biannually in straight-line sprint (5, 10 and 20 m), 5 x 10 m line-to-line sprint (LL), hurdles agility run (AR), foot tapping (FT), counter movement jump (CMJ), drop jump (DJ), reaction test (RT), 2 kg standing medicine ball throw (MBT), sit and reach test (SR) and 20 m multi-stage endurance run (ER). 359 outfield players, ages 14 – 17, remained to be analyzed in a longitudinal design. Furthermore, these pre-selected academy players were retrospectively categorized based on whether they had been drafted into a youth national team (Under 18 to 21, n = 107) or not. The differences between Group (i.e. ‘selected’ vs. ‘non-selected’) and across Age (i.e. 14, 15, 16, 17 years) were analysed using a separate ANOVA for each variable. RESULTS The main effect for Age was significant (p < .01) for all comparisons. A significant main effect for Group was found in LL, F(1, 336) = 11.34, p < .01, p η2 = .03, (1-β) = .92, in AR, F(1, 313) = 6.72, p = .01, pη2 = .02, (1-β) = .73, in CMJ, F(1, 341) = 6.52, p = .01, pη2 = .02, (1-β) = .72, and in MBT, F(1, 340) = 16.34, p < .01, pη2 = .05, (1-β) = .98 in favour of selected players. Furthermore, a significant Group x Age interaction was observed displaying a greater increase for selected group in 5 m, F(3, 1050) = 4.77, p < .01, pη2 = .01, (1-β) = .90, in 10 m, F(3, 1050) = 5.19, p < .01, pη2 = .02, (1-β) = .93, in 20 m, F(3, 1050) = 4.75, p < .01, pη2 = .01, (1-β) = .90, and in MBT, F(3,1020) = 3.41, p = .02, pη2 = .01, (1-β) = .77. CONCLUSION Regarding talent identification, we conclude that performance in soccer specific sprint tests (LL, AR), as well as in CMJ and in MBT at a young age has a small but crucial impact on future career success of elite soccer players. Concerning talent development, selected players showed higher improvements in straight-line sprint and in MBT during 5-year-academy-delay. Further research is needed to clarify these differences in development. Le Gall F, et al. (2010). J Sci Med Sport, 13, 90-95. Williams AM, Reilly T. (2000). J Sports Sci, 18, 657-667.
    16 th Annual Congress of the European College of Sport Science (ECSS)16 th Annual Congress of the European College of Sport Science (ECSS); 01/2011
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