Intervals
Source: own Strava export
This was a 2km build from half-marathon pace towards 3k pace, followed by 10 x 400m run consistently fast on a 2-minute cycle with 35-40 seconds recovery. The 2km work covered 7:22 at 3:41/km, then the 400m set targeted repeatable speed rather than a progressive pace.
The build split 3:38, 3:43, 3:45 and 3:37/km, so it did not progress cleanly. The 400m reps were mostly 1:23-1:25, with a 1:20 opener, then 1:27 and 1:29 late; recoveries stayed between 38 and 41 seconds. Heart rate reached 178 on the final 400m, with a session maximum of 185, and the set remained broadly consistent in 35 C.
Rep splits
| Rep | Time | Pace | HR | Float |
|---|---|---|---|---|
| 1 | 1:49 | 3:38/km | 167 | — |
| 2 | 1:52 | 3:43/km | 173 | — |
| 3 | 1:53 | 3:45/km | 176 | — |
| 4 | 1:49 | 3:37/km | 179 | 2:06 |
| 5 | 1:20 | 3:21/km | 166 | 0:41 |
| 6 | 1:23 | 3:28/km | 173 | 0:41 |
| 7 | 1:23 | 3:27/km | 173 | 0:40 |
| 8 | 1:23 | 3:27/km | 175 | 0:41 |
| 9 | 1:23 | 3:28/km | 163 | 0:38 |
| 10 | 1:27 | 3:36/km | 172 | 0:39 |
| 11 | 1:23 | 3:28/km | 175 | 0:40 |
| 12 | 1:24 | 3:31/km | 177 | 0:38 |
| 13 | 1:25 | 3:32/km | 176 | 0:39 |
| 14 | 1:29 | 3:43/km | 178 | 0:39 |
What the engine saw
- 14 work intervals detected from lap markers, confirmed by clear pace separation.
- Recoveries average 47s.
- Matches the athlete's own session label.
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.