Support

Questions, issues, or feedback about Impulse. Most things are answered below — for everything else, reach out directly.

Getting started

How do I film a sprint for analysis?

Record at 240fps, from the side, with the camera propped still at roughly hip height. Distance from the camera varies by height, but you should be able to comfortably see the athlete head to toe, with three to four full steps in frame. Impulse analyzes the first three steps exactly.

What iPhone do I need?

Any iPhone capable of shooting 240fps slow-motion video on the back camera works — that's the iPhone 6 or later. If your phone can shoot Slo-Mo at 240fps in the Camera app, it'll work with Impulse.

Can I record directly in the app, or do I need to film separately?

For now, Impulse works with footage you've already captured in your camera roll — film your sprint first, then upload the clip.

Understanding your results

What do shin angle, ground contact time, and flight time actually mean?

For full definitions of every metric, check the glossary at the bottom of the Lab section in the app.

How exactly is shin angle measured?

Shin angle is measured from your heel to your knee, relative to vertical, at the instant your foot contacts the ground.

Why don't I see elite benchmarks for every metric?

Elite benchmarks across all three metrics are still in progress. Impulse is the first app tracking shin angle, contact time, and flight time this precisely on a phone — which means the benchmarks don't already exist somewhere. We're building them ourselves.

Troubleshooting

Why did my video fail to process?

This is usually a connection issue — if you're on weak cellular data, the upload can time out before it reaches our backend. Try again on Wi-Fi.

Why does the pose tracking look off, or my numbers seem unusually high or low?

Tracking is occasionally imperfect. The most common cause is lighting — dim or uneven indoor gym lighting can make it harder for the pose model to track the athlete cleanly. If you get a strangely long ground contact or flight time, it's usually a tracking miss, not a real number.

What should I do if a result looks wrong?

Re-film in brighter, more even lighting. Also double check you're recording at 240fps, running parallel to the camera rather than toward or away from it, and that the camera itself isn't moving during the clip.

Data & privacy

Is my video footage stored?

No — footage isn't stored. See the Privacy Policy for full details.

Is my data shared with anyone?

No, your data is not shared.

How do I share my results?

Every session result has a share button at the top of the screen.

How do I delete my data or account?

There's no account to delete — Impulse doesn't create one. Session data lives locally on your device, so deleting it is as simple as removing the app or clearing its data in your device settings.

Pricing

Is Impulse free?

Yes — Impulse is free for the foreseeable future.

Still need help?

Send a message and you'll hear back directly — Impulse is built by one person, so replies come from the person who built it.