Intervalsconfidence 0.83
5 × 1km
Colin Dismuke50 km / marathon build
Source: own Strava export
Intervals
5 × 1km
Distance
11.2 km
Moving
50:43
Rep pace
3:47/km
Avg HR
153 bpm
Reps
5
Planned vs actual · TrainingPeaksPlanned not setRan 50:43 · 11.2 kmIF 1.34TSS 150
Shape of the sessionEasyWorkFastest
warm up
cool down
0:005 × work / float50:43
The decode
It was a threshold set prescribed as 20 minutes at 3:47/km, completed as five 1km reps.
The reps ran 3:53/km, 3:42/km, 3:46/km, 3:44/km and 3:48/km. Heart rate rose from 154 to 176 across the set, while the work segment averaged 3:47/km.
Rep splits
| Rep | Time | Pace | HR | Float |
|---|---|---|---|---|
| 1 | 3:53 | 3:53/km | 154 | — |
| 2 | 3:42 | 3:42/km | 167 | — |
| 3 | 3:46 | 3:46/km | 171 | — |
| 4 | 3:44 | 3:44/km | 172 | — |
| 5 | 3:48 | 3:48/km | 176 | — |
0.83
confidence
What the engine saw
- 5 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
Recovery25%
Z2
Endurance37%
Z3
Tempo8%
Z4
Threshold21%
Z5
VO₂max10%
Pace
Z1
Easy57%
Z2
Endurance2%
Z3
Tempo38%
Z4
Threshold2%
Z5
VO₂max0%
Z6
Speed0%
Power
Z1
Recovery1%
Z2
Endurance12%
Z3
Tempo45%
Z4
Threshold39%
Z5
VO₂max3%
Z6
Anaerobic0%
Z7
Neuro0%
Aerobic decoupling · Pa:HR+14.2%
Effort & efficiency
0.75
Running effectiveness
speed per watt/kg, reps
5.9 w/kg
Power-to-weight
rep average
2.66
Efficiency factor
norm. power per bpm
1.02
Variability index
1.0 = perfectly even power
1.6%
Rep consistency
pace spread across reps, lower is tighter
1264 kJ
Total work
mechanical energy
763 kcal
Energy
estimated burn
718 bpk
Cardiac cost
heartbeats per km
31%
Above threshold
≥ 164 bpm (Z4+)
+0:30/km
Split balance
positive split, slower 2nd half
Conditions-adjusted pace33°C · +60 m
Actual
3:47/km
Grade-adjusted
3:47/km
Heat-adjusted
3:31/km
−16s/km
True effort
3:31/km
−16s/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.