Intervalsconfidence 0.83
4 × 1.1km
Colin Dismuke50 km / marathon build
Source: own Strava export
Intervals
4 × 1.1km
Distance
11.6 km
Moving
58:14
Rep pace
3:35/km
Avg HR
144 bpm
Reps
4
Planned vs actual · TrainingPeaksPlanned 12.0 kmRan 58:14 · 11.6 kmIF 1.26TSS 153
Shape of the sessionEasyWorkFastest
warm up
cool down
0:004 × work / float58:14
The decode
The session was a four-repetition interval set rather than the planned no-interval run. Each work bout lasted 4:00.
The 3:00 recoveries separated reps run in 3:34/km, 3:34/km, 3:38/km and 3:32/km, with heart rate at 166, 171, 166 and 171. The set held together, with the fastest rep last.
Rep splits
| Rep | Time | Pace | HR | Float |
|---|---|---|---|---|
| 1 | 4:00 | 3:34/km | 166 | 3:00 |
| 2 | 4:00 | 3:34/km | 171 | 3:00 |
| 3 | 4:00 | 3:38/km | 166 | 3:00 |
| 4 | 4:00 | 3:32/km | 171 | 3:00 |
0.83
confidence
What the engine saw
- 4 work intervals detected from lap markers, confirmed by clear pace separation.
- Recoveries average 180s.
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
Recovery68%
Z2
Endurance7%
Z3
Tempo3%
Z4
Threshold13%
Z5
VO₂max9%
Pace
Z1
Easy76%
Z2
Endurance1%
Z3
Tempo2%
Z4
Threshold19%
Z5
VO₂max2%
Z6
Speed0%
Power
Z1
Recovery12%
Z2
Endurance55%
Z3
Tempo9%
Z4
Threshold10%
Z5
VO₂max13%
Z6
Anaerobic0%
Z7
Neuro0%
Aerobic decoupling · Pa:HR+6.7%
Effort & efficiency
0.74
Running effectiveness
speed per watt/kg, reps
6.3 w/kg
Power-to-weight
rep average
2.69
Efficiency factor
norm. power per bpm
1.13
Variability index
1.0 = perfectly even power
1.0%
Rep consistency
pace spread across reps, lower is tighter
1377 kJ
Total work
mechanical energy
815 kcal
Energy
estimated burn
830 bpk
Cardiac cost
heartbeats per km
21%
Above threshold
≥ 164 bpm (Z4+)
-0:10/km
Split balance
negative split, faster 2nd half
Conditions-adjusted pace24°C · +20 m
Actual
3:35/km
Grade-adjusted
3:35/km
Heat-adjusted
3:27/km
−8s/km
True effort
3:27/km
−8s/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.