3 × 4.6km
Source: own Strava export
Three 20-minute efforts off 10-minute jog recoveries formed an endurance session with a deliberate lift in the middle repetition. The first and third efforts were controlled work, while the middle effort was the planned move toward half-marathon pace; the recoveries kept the set inside a longer run rather than turning it into a standalone interval workout.
The middle effort was fastest at 4:13/km, with the first and third at 4:23/km and 4:20/km. Heart rate rose from 170 to 177 before settling at 174, so the set lifted and then held rather than fading.
Rep splits
| Rep | Time | Pace | HR | Float |
|---|---|---|---|---|
| 1 | 20:00 | 4:23/km | 170 | 10:00 |
| 2 | 20:00 | 4:13/km | 177 | 10:00 |
| 3 | 20:00 | 4:20/km | 174 | 10:00 |
What the engine saw
- 3 work intervals detected from lap markers, confirmed by clear pace separation.
- Recoveries average 600s.
Calibration flags
- Running power threshold estimated from the athlete's half-marathon best efforts (60-min power 476 W, 95% of 20-min power 460 W). Treat power zones and load as ±3%.
- Zones and running threshold are one snapshot, read 2 Jul 2026 and applied to every session in the archive. An older session is scored against today's zones, not the zones the athlete trained with then.
Engine read · editorial decode by Splits
Time in zone
The rep pace re-expressed for flat ground and cool air, the effort, not the clock. The gap between actual and true effort is the day's hidden work: conditions were taxing the clock.