Intervalsconfidence 0.83
3 × 1km
Colin Dismuke50 km / marathon build
Source: own Strava export
Intervals
3 × 1km
Distance
10.6 km
Moving
53:57
Rep pace
3:36/km
Avg HR
147 bpm
Reps
3
Planned vs actual · TrainingPeaksPlanned 12.0 kmRan 53:57 · 10.6 kmIF 1.29TSS 148
Shape of the sessionEasyWorkFastest
warm up
cool down
0:003 × work / float53:57
The decode
A three-rep interval set concentrated the work in a short middle block between easy running. The long approach and cooldown kept the session's demand confined to the repetitions rather than spreading it across the full run.
The reps held a tight pattern at 3:33/km, 3:39/km and 3:35/km, while heart rate rose from 172 to 183. The following 329 m stayed at 3:39/km with heart rate at 184, so the effort did not drop immediately after the final repetition.
Rep splits
| Rep | Time | Pace | HR | Float |
|---|---|---|---|---|
| 1 | 3:33 | 3:33/km | 172 | — |
| 2 | 3:39 | 3:39/km | 180 | — |
| 3 | 3:35 | 3:35/km | 183 | — |
0.83
confidence
What the engine saw
- 3 work intervals detected from lap markers, confirmed by clear pace separation.
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
Heart rate
Z1
Recovery52%
Z2
Endurance28%
Z3
Tempo2%
Z4
Threshold3%
Z5
VO₂max16%
Pace
Z1
Easy80%
Z2
Endurance1%
Z3
Tempo4%
Z4
Threshold15%
Z5
VO₂max0%
Z6
Speed0%
Power
Z1
Recovery3%
Z2
Endurance52%
Z3
Tempo25%
Z4
Threshold6%
Z5
VO₂max12%
Z6
Anaerobic1%
Z7
Neuro0%
Aerobic decoupling · Pa:HR+1.8%
Effort & efficiency
0.69
Running effectiveness
speed per watt/kg, reps
6.8 w/kg
Power-to-weight
rep average
2.66
Efficiency factor
norm. power per bpm
1.11
Variability index
1.0 = perfectly even power
1.1%
Rep consistency
pace spread across reps, lower is tighter
1396 kJ
Total work
mechanical energy
776 kcal
Energy
estimated burn
906 bpk
Cardiac cost
heartbeats per km
19%
Above threshold
≥ 164 bpm (Z4+)
-0:21/km
Split balance
negative split, faster 2nd half
Conditions-adjusted pace24°C · +17 m
Actual
3:36/km
Grade-adjusted
3:36/km
Heat-adjusted
3:28/km
−8s/km
True effort
3:28/km
−8s/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.