Intervalsconfidence 0.88
4 × 1.2km treadmill
Colin Dismuke50 km / marathon build
Source: own Strava export
Intervals
4 × 1.2km treadmill
Distance
6.2 km
Moving
30:49
Rep pace
4:14/km
Avg HR
152 bpm
Reps
4
Shape of the sessionEasyWorkFastest
warm up
cool down
0:004 × work / float30:43
The decode
Four 1.2km treadmill reps formed a cut-down interval session. The treadmill made pace the controlled variable, but the recorded splits did not correspond cleanly with the treadmill display, which reportedly moved from 3:38/km to 3:00/km.
The first three reps clustered at 4:18/km, 4:20/km and 4:17/km before the final rep cut to 4:01/km. Heart rate rose from 157 to 169 across the set, while the 60-second recoveries kept the work continuous.
Rep splits
| Rep | Time | Pace | HR | Float |
|---|---|---|---|---|
| 1 | 5:00 | 4:18/km | 157 | 1:00 |
| 2 | 5:00 | 4:20/km | 156 | 1:00 |
| 3 | 5:00 | 4:17/km | 160 | 1:00 |
| 4 | 5:00 | 4:01/km | 169 | 1:00 |
0.88
confidence
What the engine saw
- 4 work intervals detected from lap markers, confirmed by clear pace separation.
- Rep paces descend across the set (a cut-down / progression).
- Recoveries average 60s.
- Matches the athlete's own session label.
Calibration flags
- 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
Heart rate
Z1
Recovery31%
Z2
Endurance10%
Z3
Tempo31%
Z4
Threshold19%
Z5
VO₂max10%
Pace
Z1
Easy40%
Z2
Endurance31%
Z3
Tempo27%
Z4
Threshold0%
Z5
VO₂max2%
Z6
Speed0%
Aerobic decoupling · Pa:HR+7%
Effort & efficiency
2.9%
Rep consistency
pace spread across reps, lower is tighter
454 kcal
Energy
estimated burn
754 bpk
Cardiac cost
heartbeats per km
28%
Above threshold
≥ 164 bpm (Z4+)
-0:18/km
Split balance
negative split, faster 2nd half
Conditions-adjusted pace34°C
Actual
4:14/km
Grade-adjusted
4:14/km
Heat-adjusted
3:56/km
−18s/km
True effort
3:56/km
−18s/km
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.