Intervalsconfidence 0.83
6 × 1km
Colin Dismuke50 km / marathon build
Source: own Strava export
Intervals
6 × 1km
Distance
11.1 km
Moving
48:06
Rep pace
3:30/km
Avg HR
164 bpm
Reps
6
Planned vs actual · TrainingPeaksPlanned 39:54 · 9.0 kmRan 48:06 · 11.1 kmIF 1.40TSS 154
Shape of the sessionEasyWorkFastest
warm up
cool down
0:006 × work / float48:06
The decode
This was a six-repetition 1 km interval set with 85-90-second recoveries, intended to establish a benchmark through even pacing.
The first three reps ran in 3:24/km, 3:26/km and 3:27/km, before the final three came in at 3:36/km, 3:32/km and 3:36/km. Heart rate rose from 169 on rep one to 181 on reps five and six; a headwind affected reps 2 and 4.
Rep splits
| Rep | Time | Pace | HR | Float |
|---|---|---|---|---|
| 1 | 3:24 | 3:24/km | 169 | 1:25 |
| 2 | 3:26 | 3:26/km | 178 | 1:25 |
| 3 | 3:27 | 3:27/km | 178 | 1:25 |
| 4 | 3:36 | 3:36/km | 178 | 1:25 |
| 5 | 3:32 | 3:32/km | 181 | 1:30 |
| 6 | 3:36 | 3:36/km | 181 | 5:18 |
0.83
confidence
What the engine saw
- 6 work intervals detected from lap markers, confirmed by clear pace separation.
- Recoveries average 125s.
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
Recovery12%
Z2
Endurance21%
Z3
Tempo20%
Z4
Threshold12%
Z5
VO₂max35%
Pace
Z1
Easy51%
Z2
Endurance5%
Z3
Tempo10%
Z4
Threshold19%
Z5
VO₂max14%
Z6
Speed1%
Power
Z1
Recovery6%
Z2
Endurance16%
Z3
Tempo34%
Z4
Threshold24%
Z5
VO₂max21%
Z6
Anaerobic0%
Z7
Neuro0%
Aerobic decoupling · Pa:HR+14.6%
Effort & efficiency
0.76
Running effectiveness
speed per watt/kg, reps
6.3 w/kg
Power-to-weight
rep average
2.62
Efficiency factor
norm. power per bpm
1.06
Variability index
1.0 = perfectly even power
2.3%
Rep consistency
pace spread across reps, lower is tighter
1260 kJ
Total work
mechanical energy
789 kcal
Energy
estimated burn
754 bpk
Cardiac cost
heartbeats per km
47%
Above threshold
≥ 164 bpm (Z4+)
+0:17/km
Split balance
positive split, slower 2nd half
Conditions-adjusted pace34°C · +29 m
Actual
3:30/km
Grade-adjusted
3:30/km
Heat-adjusted
3:15/km
−15s/km
True effort
3:15/km
−15s/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.