Standing-start biomechanics in elite track cycling: inertial launch dynamics at the 2022 UCI World Championships

The standing start exerts a decisive influence on track-cycling performance, yet its in-competition biomechanics remain under-documented. We analysed a descriptive case-series recorded at the 2022 UCI Track Cycling World Championships. The primary series comprised six men’s team-sprint starters; two women’s team-sprint and two men’s team-pursuit starts were retained as additional illustrative cases. High-speed video (240 Hz) and a domain-specific markerless pose-estimation pipeline were used to reconstruct whole-body centre-of-mass (CoM) motion. We descriptively examined which features of CoM timing and direction relative to gate release characterised the starts with the best immediate performance, quantified by the instantaneous front-wheel velocity at the cue, Vstart, and the time to the first 30 cm, T30cm. In the six men’s team-sprint cases, the best early starts combined predominantly horizontal CoM paths with high forward CoM velocity reached before the cue and rapid CoM deceleration around t=0. Order-of-magnitude estimates indicate that the associated inertial drive can transiently exceed the drivetrain-transmitted propulsive force. Because the sample is small and purposively selected, the analysis is descriptive rather than population-inferential. The observations nevertheless identify a mechanically coherent, coachable target: build forward body momentum before release and transfer it to the bicycle as the gate opens.