Comparison of Sprint Timing Methods on Performance, and Displacement and Velocity at Timing Initiation

Weakley, J, McCosker, C, Chalkley, D, Johnston, R, Munteanu, G, and Morrison, M. Comparison of sprint timing methods on performance, and displacement and velocity at timing initiation. J Strength Cond Res 37(1): 234-238, 2023-Sprint testing is commonly used to assess speed and acceleration in athletes. However, vastly different outcomes have been reported throughout the literature. These differences are likely due to the sprint timing method rather than differences in athlete ability. Consequently, this study compared different sprint starting methods on sprint time and quantified the velocity and displacement of the athlete at the moment timing is initiated. Starting in a staggered 2-point stance, 12 team sport athletes were required to accelerate 10 meters for 10 repetitions. During each repetition, 5 independent timing methods were triggered. The methods were (a) triggering a Move sensor; (b) starting 50 cm behind the line; (c) triggering a front-foot switch; (d) triggering a rear-foot switch; and (e) starting with the front foot on the line. Timing for each method was initiated at different points during the acceleration phase, and the displacement and velocity of the centroid of the pelvis at the point of timing initiation was assessed under high-speed motion capture. The Move sensor had the smallest displacement and lowest velocity at the point of timing initiation, whereas the front-foot trigger demonstrated the largest displacement and highest velocities. Trivial to very large effect size differences were observed between all methods in displacement and velocity at the point of timing initiation. Furthermore, small to very large differences in time to 5 m were found. These findings emphasize that sprint outcomes should not be compared, unless starting methods are identical. In addition, to detect real change in performance, consistent standardized protocols should be implemented.