Influence of Test Distance on Change of Direction Speed Test Results.

This study assessed the relationships between linear running velocity and change of direction (CoD) ability and how assessing CoD ability over distances ≤5 m influences test reliability. Participants (n = 15) from amateur rugby league teams performed 3 trials of a 20-m sprint test (light gates at 5, 10, and 20 m) and 6 trials of the 5-0-5 agility test. Twelve participants repeated the 5-0-5 test several weeks later. A three-dimensional motion capture system (250 Hz) was used to track the center of mass at 0.3, 0.5, and 1.0 m either side of the turn and identify specific CoD phase times. Pearson's correlations showed strong significant relationships between the 5-0-5 time and 5-m (r = 0.89, p < 0.001), 10-m (r = 0.91, p < 0.001), and 20-m sprint times (r = 0.93, p < 0.001). However, the strength of these relationships decreased (r < 0.65, p > 0.05) when CoD ability was measured over distances less than 0.5 m. Analysis of coefficient of variation (CV%) data indicated that the 5-0-5 test had high intratest (CV% = 2.8) and intertest reliability (CV% = 1.3), with these data decreasing for distances less than 1 m (CV% = 3.5-6.9). Specific movement phase times were the least reliable measures of CoD ability (CV% = 4.7-53.6). Results suggest a bias between high-speed linear running ability and 5-0-5 time. However, an effective compromise can be found between test reliability and the external validity by assessing CoD ability over 1 m. Findings indicate that the current practice of assessing CoD ability over large distances in questionable.