Importance of Reactive Agility and Change of Direction Speed in Differentiating Performance Levels in Junior Soccer Players: Reliability and Validity of Newly Developed Soccer-Specific Tests

Abstract

Agility is a significant determinant of success in soccer; however, studies have rarely presented and evaluated soccer-specific tests of reactive agility (S_RAG) and non-reactive agility (change of direction speed – S_CODS) or their applicability in this sport. The aim of this study was to define the reliability and validity of newly developed tests of the S_RAG and S_CODS to discriminate between the performance levels of junior soccer players. The study consisted of 20 players who were involved at the highest national competitive rank (all males; age: 17.0 ± 0.9 years), divided into three playing positions (defenders, midfielders, and forwards) and two performance levels (U17 and U19). Variables included body mass (BM), body height, body fat percentage, 20-m sprint, squat jump, countermovement jump, reactive-strength-index, unilateral jump, 1RM-back-squat, S_CODS, and three protocols of S_RAG. The reliabilities of the S_RAG and S_CODS were appropriate to high (ICC: 0.70 to 0.92), with the strongest reliability evidenced for the S_CODS. The S_CODS and S_RAG shared 25–40% of the common variance. Playing positions significantly differed in BM (large effect-size differences [ES]; midfielders were lightest) and 1RM-back-squat (large ES; lowest results in midfielders). The performance levels significantly differed in age and experience in soccer; U19 achieved better results in the S_CODS (t-test: 3.61, p < 0.05, large ES) and two S_RAG protocols (t-test: 2.14 and 2.41, p < 0.05, moderate ES). Newly developed tests of soccer-specific agility are applicable to differentiate U17 and U19 players. Coaches who work with young soccer athletes should be informed that the development of soccer-specific CODS and RAG in this age is mostly dependent on training of the specific motor proficiency.

Reliability and validity of field‐based fitness tests in youth soccer players

“…Comparable to the importance of linear sprint ability, the ability to efficiently change direction and velocity is also of significance to soccer performance (Pojskic et al, 2018), due to its multidimensional nature (Stølen et al, 2005;Strudwick et al, 2002). As discussed previously (Section 2.2.1.1), high intensity activity (including sprinting, accelerations, decelerations, and COD) has increased substantially during match play in senior soccer (Barnes et al, 2014;Bush et al, 2015).…”

Test–retest reliability of physical fitness tests among young athletes: The FITescola® battery

“…The validation of the tests that comprise the FITescola ® battery and the reliability of some tests, such as the 20 m shuttle run, horizontal jump, 4 × 10 m shuttle run, push‐up test and the sit and reach has been previously examined in youth (general population) (Artero et al, 2011; Baumgartner, Oh, Chung, & Hales, 2002; Ortega, Artero, et al, 2008; Ruiz et al, 2011; Vanhelst et al, 2016). Although some of the tests comprising the FITescola ® battery (e.g., the speed test) were tested for reliability in athlete samples from specific sports (e.g., football) (Pojskic et al, 2018), the reliability of the FITescola ® battery as a whole was never tested among young athletes.…”

Reliability of Change of Direction and Agility Assessments in Youth Soccer Players

“…The COD tests examined within this study demonstrated a better intersession reliability than previously reported [18,28,50]. The better reliability demonstrated could potentially be explained due to the high performance standard of this sample, previously proposed as an influencer of test reliability in adolescent athletes [35,51].…”

“…Considering the varied physical demands imposed by different COD tests [10,15,16], the shorter test duration and singular acute change of direction may explain the improved intersession reliability we observed for the Y-SprintPRE compared to previous research [28,50]. The ability to change direction is angle dependent and affected by entry velocity into the COD [10,15,16].…”

“…The ability to change direction is angle dependent and affected by entry velocity into the COD [10,15,16]. Consequently, the technique and loading required during execution of a 45 • cut during forward sprinting (as required by the Y-SprintPRE) compared to a 90 • -180 • COD (as required by tests included in comparable research) [15,28,50] will vary. We suggest that the Y-SprintPRE places a greater emphasis on linear sprint ability, potentially reducing the challenge placed upon the typically underdeveloped eccentric strength qualities and limited movement competency observed in youth athletes [18,30,34,36,37].…”