Intervalsconfidence 0.83
3 × 2km
Colin Dismuke50 km / marathon build
Source: own Strava export
Intervals
3 × 2km
Distance
11.3 km
Moving
47:44
Rep pace
3:54/km
Avg HR
173 bpm
Reps
6
Planned vs actual · TrainingPeaksPlanned 56:16 · 13.0 kmRan 47:44 · 11.3 kmIF 1.38TSS 149
Shape of the sessionEasyWorkFastest
warm up
cool down
0:006 × work / float47:44
The decode
It was a threshold set of three 2km hard blocks separated by 1km floats. The session was completed in 38 C.
The work blocks moved from 3:51/km to 3:54/km to 3:56/km, while heart rate rose from 169 to 178 to 183. The pace drift was contained across the set.
Rep splits
| Rep | Time | Pace | HR | Float |
|---|---|---|---|---|
| 1 | 3:52 | 3:52/km | 169 | — |
| 2 | 3:50 | 3:50/km | 177 | 4:17 |
| 3 | 3:53 | 3:53/km | 178 | — |
| 4 | 3:54 | 3:54/km | 178 | 4:15 |
| 5 | 3:56 | 3:56/km | 183 | — |
| 6 | 3:56 | 3:56/km | 185 | 4:29 |
0.83
confidence
What the engine saw
- 6 work intervals detected from lap markers, confirmed by clear pace separation.
- Recoveries average 260s.
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
Endurance10%
Z3
Tempo3%
Z4
Threshold28%
Z5
VO₂max57%
Pace
Z1
Easy17%
Z2
Endurance36%
Z3
Tempo47%
Z4
Threshold0%
Z5
VO₂max0%
Z6
Speed0%
Power
Z1
Recovery1%
Z2
Endurance7%
Z3
Tempo43%
Z4
Threshold48%
Z5
VO₂max2%
Z6
Anaerobic0%
Z7
Neuro0%
Aerobic decoupling · Pa:HR+7.2%
Effort & efficiency
0.74
Running effectiveness
speed per watt/kg, reps
5.8 w/kg
Power-to-weight
rep average
2.42
Efficiency factor
norm. power per bpm
1.02
Variability index
1.0 = perfectly even power
0.9%
Rep consistency
pace spread across reps, lower is tighter
1251 kJ
Total work
mechanical energy
826 kcal
Energy
estimated burn
772 bpk
Cardiac cost
heartbeats per km
85%
Above threshold
≥ 164 bpm (Z4+)
+0:05/km
Split balance
positive split, slower 2nd half
Conditions-adjusted pace38°C · +32 m
Actual
3:54/km
Grade-adjusted
3:54/km
Heat-adjusted
3:34/km
−20s/km
True effort
3:34/km
−20s/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.