Sprint Acceleration Analysis
Impulse
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Different sports, same three steps. Whoever accelerates faster off the mark usually wins the play.
Shin angle, ground contact time, and flight time — measured frame by frame, no lab required.
Every time your foot hits the ground, the ground hits back — Newton's third law. Land with your shin straight up and down, and that force comes straight back up, wasted. The more your shin angles forward at contact, the less force you leak upward — and the more of it drives you forward instead.
Impulse measures how long your foot stays on the ground each step. Up to a point, more time on the ground means more time to apply force — but past that point, you're just not reacting off the ground fast enough. Where that balance sits isn't fixed: it varies by athlete, and shifts step by step as you accelerate. Flight time — the moment between steps when neither foot is down — tells the other half of that story.
Impulse tracks how your shin angle, contact time, and flight time each correlate with your speed across every session — so you know what's working when you run your fastest, and what still needs improvement.
Impulse is built by one person — Keertan Sawtell. He played varsity basketball at Riverdale, and heads to Boston College this fall.
Free to start. Available now on the App Store.
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