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

ABSTRACT

This study aimed to establish between-day reliability and validity of commonly used field-based fitness tests in youth soccer players of varied age and playing standards, and to discriminate between players without (“unidentified”) or with (“identified”) a direct route to professional football through their existing club pathway. Three-hundred-and-seventy-three Scottish youth soccer players (U11–U17) from three different playing standards (amateur, development, performance) completed a battery of commonly used generic field-based fitness tests (grip dynamometry, standing broad jump, countermovement vertical jump, 505 (505COD) and T-Drill (T-Test) change of direction and 10/20 m sprint tests) on two separate occasions within 7–14 days. The majority of field-based fitness tests selected within this study proved to be reliable measures of physical performance (ICC = 0.83–0.97; p < .01). However, COD tests showed weaker reliability in younger participants (ICC = 0.57–0.79; p < .01). The field-based fitness testing battery significantly discriminated between the unidentified and identified players; χ² (7) = 101.646, p < .001, with 70.2% of players being correctly classified. We have shown field-based fitness tests to be reliable measures of physical performance in youth soccer players. However, results from the 505COD and T-Test change of direction tests may be more variable in younger players, potentially due to complex demands of these tests and the limited training age established by these players. While the testing battery selected in this study was able to discriminate between unidentified and identified players, findings were inconsistent when attempting to differentiate between individual playing standards within the “identified” player group (development vs. performance).

Key words:

• Selection
• performance
• discriminate
• profiling
• adolescent
• development

Acknowledgements

The results of the current study do not constitute the endorsement of any product by the authors or the journal. This paper presents independent research and the views expressed are those of the authors. The authors wish to thank the players, coaches, and staff from the participating teams for their efforts and co-operation during the data collection of this study.

Disclosure statement

No potential conflict of interest was reported by the authors.