Intervalsconfidence 0.83
3 × 1km
Colin Dismuke50 km / marathon build
Source: own Strava export
Intervals
3 × 1km
Distance
8.3 km
Moving
40:41
Rep pace
4:26/km
Avg HR
183 bpm
Reps
3
Shape of the sessionEasyWorkFastest
warm up
0:003 × work / float40:41
The decode
This was a three-repetition interval session: 3 × 1km with recoveries averaging 305s.
The work progressed from 4:36/km to 4:24/km to 4:19/km. Heart rate rose from 188 to 189 to 195.
Rep splits
| Rep | Time | Pace | HR | Float |
|---|---|---|---|---|
| 1 | 4:36 | 4:36/km | 188 | 5:05 |
| 2 | 4:24 | 4:24/km | 189 | — |
| 3 | 4:19 | 4:19/km | 195 | — |
0.83
confidence
What the engine saw
- 3 work intervals detected from lap markers, confirmed by clear pace separation.
- Recoveries average 305s.
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
Recovery2%
Z2
Endurance2%
Z3
Tempo13%
Z4
Threshold2%
Z5
VO₂max81%
Pace
Z1
Easy58%
Z2
Endurance40%
Z3
Tempo2%
Z4
Threshold0%
Z5
VO₂max0%
Z6
Speed0%
Power
Z1
Recovery4%
Z2
Endurance25%
Z3
Tempo49%
Z4
Threshold22%
Z5
VO₂max0%
Z6
Anaerobic0%
Z7
Neuro0%
Aerobic decoupling · Pa:HR+1.2%
Effort & efficiency
0.82
Running effectiveness
speed per watt/kg, reps
4.6 w/kg
Power-to-weight
rep average
2.10
Efficiency factor
norm. power per bpm
1.03
Variability index
1.0 = perfectly even power
2.7%
Rep consistency
pace spread across reps, lower is tighter
911 kJ
Total work
mechanical energy
680 kcal
Energy
estimated burn
896 bpk
Cardiac cost
heartbeats per km
82%
Above threshold
≥ 164 bpm (Z4+)
-0:23/km
Split balance
negative split, faster 2nd half
Conditions-adjusted pace18°C · +148 m
Actual
4:26/km
Grade-adjusted
4:26/km
Heat-adjusted
4:23/km
−3s/km
True effort
4:23/km
−3s/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.