Event Selector
The row of distance pills (1500m through Marathon) that switches every dashboard number to the selected race distance.
Source: components/home/projection-tile.tsx (event pills)
What You See
A horizontal row of distance pills — 1500m, 3K, 5K, 10K, Half Marathon, and Marathon — at the top of the Time Projection card. The selected pill is highlighted. Tapping a pill switches the projection, range, drivers, and the rest of the dashboard to that race distance. If you have upcoming races saved, your race deck appears alongside it with per-race projections.
How the Numbers Work
All event projections come from a single API call that returns predictions for every distance. Each distance is calculated by scaling the 5K projection using a power-law formula (Riegel formula) that accounts for how performance changes as the race gets longer. The range and improvement numbers follow the same logic as the main Projection Tile.
Step by Step
Models & algorithms used: Riegel
All distances are computed from the 5K base projection using the Riegel power-law formula: Time2 = Time1 times (Distance2 / Distance1) raised to an exponent. The default exponent is 1.06. PIRX can adjust this exponent based on your weekly mileage (the Modified Riegel method lowers it for higher-volume runners and raises it for lower-volume runners, clamped between 0.98 and 1.15). When scaling crosses the 5K boundary (shorter vs longer), the exponent shifts by 0.02 to account for the aerobic-anaerobic transition. An environmental adjustment of 0.35 percent per degree outside the 10-17.5 C optimal band can also be applied. Each card shows the scaled time, its own range, and its own 21-day change. Tapping a card switches all dashboard components to that event without making a new server request.