Tool

WINertia

WINertia is our in-browser sprint analysis tool. Upload a video from any phone, hit play, and get a live skeleton overlay plus the mechanics that actually decide races — no app install, no cloud upload of your data.

Analyze a video See plans

Pose overlay

Google BlazePose runs on-device to draw a real-time skeleton on top of your sprint footage.

Cadence

Steps per minute, computed automatically from ankle strike detection over a rolling 10-second window.

Stride length

Estimated stride distance relative to hip width — track opening length rep to rep and week to week.

Hip drop

Pelvic tilt angle at each foot strike. A key marker for glute-med strength and single-leg stiffness.

Ground contact

Estimated GCT in milliseconds. The single biggest separator between developmental and elite sprinters.

Manual timer + splits

Tap to mark start, splits, and finish while watching. Save them to the video for later comparison.

How to use it

Upload a side-on video on My Videos. 60–120 fps works best.
Open the video and click Open WINertia analysis.
Press play. The skeleton draws live and the metrics card refreshes 4×/second.
Use the manual timer to mark 10m / 30m / finish splits and save them.
Share the video with your coach for a timestamped comment review.

What it isn't

WINertia is a coaching aid, not a laser timing system. GCT and stride are pose-derived estimates — great for spotting trends and asymmetries, not for submitting to a record book. For hard numbers, pair it with your electronic timing and use WINertia to understand why the numbers moved.