Running BrowserRunning Browser · Models and assumptions
How Running Browser accounts for wind
The wind number in a weather report is an input to a model. It is not a measurement of the air resistance you experienced throughout the run.
The pace model’s assumptions
The ideal-pace model assumes mixed wind exposure on a loop. It uses the wind above the default 5 km/h threshold, multiplies that excess by 0.65 to approximate runner-height wind, and compares it with running speed. The air-drag share is 0.04 in the implementation.
These coefficients belong to the application’s approximation. The cited research provides background on air resistance; it should not be read as validation of every coefficient or every individual result.
Why one direction is different
A route predominantly into a headwind does not fit the loop assumption. Trees, buildings, gusts and changes in direction are also absent from the calculation. That makes the estimate a useful reference point, not a route-specific aerodynamic reconstruction.
Effort and ideal pace answer different questions
The app also has a configurable effort adjustment for wind. That raises a training-effort score; the ideal-pace calculation estimates a pace under different conditions. The two adjustments use different models and should not be interchanged.
The science book’s conditions and fitness chapters explain the distinction in more detail. Try the wind calculator to see only the ideal-pace model, using the default thresholds.
Background reading
These references are also cited in the full science book. They provide background, not independent validation of the app’s estimates.
- Pugh, L.G. (1971). The influence of wind resistance in running and walking. Journal of Physiology. Reference 3 in the book
Keep the plan and the run together
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