Running BrowserThe values the app starts with. The first table can be changed in Settings; the second is fixed in the code.
| Setting | Default |
|---|---|
| Lactate threshold pace | 4:00/km |
| Default Z2 (easy) pace | 5:10/km |
| Wind: no adjustment up to | 5 km/h |
| Wind: for each km/h above that | 1% |
| Elevation: adjusted from a gain of | 50 m |
| Elevation: per metre of gain per km | 1% |
| Unpaved terrain: a fully unpaved run | 10% |
| Rough terrain: a fully rough run | 25% |
| Rain | 5% |
| Snow | 10% |
| Temperature: comfortable range | 5–22 °C |
| Temperature: per °C outside it | 1% |
| Constant | Value |
|---|---|
| Effort at threshold | 2.85 |
| Effort, per second slower than threshold | × e^−0.0115 per second |
| Effort, per second faster than threshold | × e^0.01725 per second |
| Pace-effort table | 60 s faster to 90 s slower, every 10 s |
| Fatigue window | 21 days |
| Fatigue decay rate | 0.135 per day |
| Days with an entry needed for Fatigue | 15 days |
| Tempo score reference heart rate | 165 bpm |
| Threshold: a race lasting | 55 min |
| Race equivalence exponent (Riegel) | 1.06 |
| Extra slowdown for the marathon | 2% |
| Fitness gain per build week | 0.3%, 4% in all |
| Weekly volume steps | 6% below 25 km, 5% to 50 km, 4% to 80 km, 3% above |
| Long run, share of the week (3 to 7 days) | 35% · 32% · 30% · 28% · 26% |
| Long run, at most | 40% of the week, 150 min (165 min for the marathon) |
| Second key session from | 6 days and 50 km a week |
Sources & further reading
Background references
The values above come from Running Browser’s calculation code. These references provide background for the models; they do not independently validate the app’s chosen constants.
- Modeling elite athletic performance
Physiological Testing of the High-Performance Athlete · Library record
- A new approach to monitoring exercise training
Journal of Strength and Conditioning Research
- Quantifying training intensity distribution in elite endurance athletes: is there evidence for an “optimal” distribution?
Scandinavian Journal of Medicine & Science in Sports
- Athletic records and human endurance
American Scientist
- Daniels’ Running Formula (3rd ed.)
Human Kinetics · Library record
- Energy cost of walking and running at extreme uphill and downhill slopes
Journal of Applied Physiology
- Impact of weather on marathon-running performance
Medicine & Science in Sports & Exercise