Intervalsconfidence 0.83
6 × 1km
Colin Dismuke50 km / marathon build
Source: own Strava export
Intervals
6 × 1km
Distance
21.2 km
Moving
94:58
Rep pace
3:31/km
Avg HR
142 bpm
Reps
6
Planned vs actual · TrainingPeaksPlanned 16.0 kmRan 1:34:58 · 21.2 kmIF 1.51TSS 358
Shape of the sessionEasyWorkFastest
warm up
cool down
0:006 × work / float94:58
The decode
The session was a six-by-1km interval set within a 12-18km prescription.
The reps ran in 3:35, 3:31, 3:34, 3:29, 3:29 and 3:30, with heart rate rising from 142 to 150. The set held together as the pace moved from 3:35/km to 3:29/km before the final 3:30/km rep.
Rep splits
| Rep | Time | Pace | HR | Float |
|---|---|---|---|---|
| 1 | 3:35 | 3:35/km | 142 | 2:26 |
| 2 | 3:31 | 3:31/km | 146 | 2:29 |
| 3 | 3:34 | 3:34/km | 146 | 2:29 |
| 4 | 3:29 | 3:29/km | 144 | 2:28 |
| 5 | 3:29 | 3:29/km | 149 | 2:32 |
| 6 | 3:30 | 3:30/km | 150 | 0:36 |
0.83
confidence
What the engine saw
- 6 work intervals detected from lap markers, confirmed by clear pace separation.
- Rep paces descend across the set (a cut-down / progression).
- Recoveries average 130s.
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
Recovery35%
Z2
Endurance64%
Z3
Tempo1%
Z4
Threshold0%
Z5
VO₂max0%
Pace
Z1
Easy33%
Z2
Endurance46%
Z3
Tempo4%
Z4
Threshold15%
Z5
VO₂max3%
Z6
Speed0%
Power
Z1
Recovery2%
Z2
Endurance23%
Z3
Tempo31%
Z4
Threshold35%
Z5
VO₂max9%
Z6
Anaerobic0%
Z7
Neuro0%
Aerobic decoupling · Pa:HR-4.7%
Effort & efficiency
0.76
Running effectiveness
speed per watt/kg, reps
6.2 w/kg
Power-to-weight
rep average
2.90
Efficiency factor
norm. power per bpm
1.05
Variability index
1.0 = perfectly even power
1.1%
Rep consistency
pace spread across reps, lower is tighter
2643 kJ
Total work
mechanical energy
1409 kcal
Energy
estimated burn
740 bpk
Cardiac cost
heartbeats per km
0%
Above threshold
≥ 164 bpm (Z4+)
-0:18/km
Split balance
negative split, faster 2nd half
Conditions-adjusted pace15°C · +144 m
Actual
3:31/km
Grade-adjusted
3:31/km
Heat-adjusted
3:31/km
True effort
3:31/km
The rep pace re-expressed for flat ground and cool air, the effort, not the clock. Adjustments are modest on this one; on a hot day or a hilly route this is where the real work hides.