Concurrent validity of single- and dual-beam timing systems for linear and change of direction speed testing in youth soccer players

Abstract

This study investigates the concurrent validity of the Sportreact single-beam timing system with a standard dual-beam system for the evaluation of linear and change of direction speed. Forty-two youth soccer players (age = 12.9 ± 1.1 years) performed linear sprints (10 and 30 m splits) and 505 Agility Test. The times were measured by both systems simultaneously. The single-beam timing system was set at a height of 64 cm from the ground, while the dual-beam system was set at 67 and 90 cm for the lower and upper beam, respectively. The results showed very high intraclass correlation coefficients for the 10 m sprint (ICC (95% CI); 0.95 (0.93–0.98)), 30 m sprint (0.99 (0.98–0.99)), and 505 Agility Test (0.98 (0.98–0.99)), with a low typical error of estimates (TEEs (%) = 2.16%, 1.12%, and 1.05%, respectively). However, TEE of 0.046 s in the 10 m sprint test overlapped the smallest worthwhile change (≈0.030 s). Bland-Altman analyses showed 95% LoA ranging from −0.086 to 0.093 s for the 10 m sprint, −0.115 to 0.106 s for the 30 m sprint, and −0.055 to 0.049 for 505 agility tests. The Sportreact single-beam timing system provides a useful tool for linear sprint (≥30 m) and change of direction speed tests only when considering heterogeneous groups but not individual athletes. However, this system should not be used interchangeably with a dual-beam systems for the assessment of linear and change of direction sprint tests in youth team sport players.