Marathon Pacing for a swimmer's lap
Simulate a swimmer's lap live in your browser. This runs the real Marathon Pacing solver — adjust the inputs, watch it respond instantly, and export the result. No install, no account.
Controls
Presets
Race pace is simply your goal time divided by the distance, but how you distribute it matters. A negative split — starting conservatively and finishing faster — is how nearly every marathon world record is run, because going out too hard burns glycogen and invites the dreaded wall. Even pacing is the safe default.
Data Inspector
Governing equation
Runs locally in your browser — free forever. Scale to the cloud when reality gets heavy.
About this simulation
The full Marathon Pacing tool models a swimmer's lap with the same numerics engineers and scientists use — running entirely client-side. Change any parameter and the result updates in real time, so you can build intuition, check a design, or teach the concept without spreadsheets or installs.
More you can do with Marathon Pacing
Other ways to simulate a swimmer's lap
Frequently asked questions
- How do I simulate a swimmer's lap?
- Open this page and use the live Marathon Pacing tool below — set your inputs and the simulation runs instantly in your browser using real numerics. No install, no account needed.
- Is it free?
- Yes. The simulation runs free in your browser. A one-time unlock or a Pro plan adds advanced parameters, saved presets, data import, and clean exports.
- Can I use my own numbers?
- Absolutely — every input is adjustable, and with data import you can drive a swimmer's lap from your own measurements.