Phases
The five phases of a sprint.
A sprint is not one movement repeated. It is five distinct mechanical problems solved in sequence, and the same measurement can be correct in one phase and a serious fault in the next. This is why Stride reports every result against the phase it was taken in rather than averaging across a run.
- 01Block startSet position to second ground contactThe block start is the phase from the set position through block clearance and the first two ground contacts, in which the sprinter converts a static position into forward velocity against the blocks.
- 02Drive phaseRoughly the first 10–20 mThe drive phase is the portion of a sprint immediately after block clearance in which the athlete is still accelerating hard from a forward-leaning position, with the foot landing behind the centre of mass and contact times still long.
- 03TransitionRoughly 20–35 mThe transition is the phase between the drive phase and maximum velocity, in which the sprinter moves from a forward-leaning, push-dominant action into an upright, reactive one.
- 04Maximum velocityRoughly 35–70 mMaximum velocity is the phase of a sprint in which the athlete reaches and briefly holds their highest speed, running upright with short ground contacts, long flight times, and the foot landing close to beneath the hips.
- 05DecelerationRoughly the final 20–30 mDeceleration is the final phase of a sprint in which velocity falls away from the athlete’s maximum, driven by neuromuscular fatigue rather than by any deliberate change in effort.
Why phase matters more than the number
A trunk angle of 42° from vertical is exactly right on the first step out of blocks and a serious fault at 60 m. A ground contact of 0.19 s is correct on the first contact and impossibly slow at maximum velocity. A tool that reports one average value for a whole run has discarded the only context that made the number meaningful.
The measurements themselves are defined on the what we measure page, each with its typical elite range and the research behind it.