Intervalsconfidence 0.83
3 × 3km
Colin Dismuke50 km / marathon build
Source: own Strava export
Intervals
3 × 3km
Distance
13.6 km
Moving
56:12
Rep pace
3:44/km
Avg HR
160 bpm
Reps
3
Planned vs actual · TrainingPeaksPlanned 1:10:12 · 15.7 kmRan 56:12 · 13.6 kmIF 1.44TSS 192
Shape of the sessionEasyWorkFastest
warm up
cool down
0:003 × work / float56:12
The decode
It was a threshold set of 3 × 3km with 2:00 recoveries between reps, preceded by a warm-up and followed by a cooldown.
The reps ran 3:45/km, 3:42/km and 3:44/km, keeping the pace tightly grouped. Heart rate was 166, 158 and 184 across the reps, with a 190 maximum.
Rep splits
| Rep | Time | Pace | HR | Float |
|---|---|---|---|---|
| 1 | 11:16 | 3:45/km | 166 | 2:00 |
| 2 | 11:07 | 3:42/km | 158 | 2:00 |
| 3 | 11:11 | 3:44/km | 184 | 2:00 |
0.83
confidence
What the engine saw
- 3 work intervals detected from lap markers, confirmed by clear pace separation.
- Recoveries average 120s.
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
Recovery21%
Z2
Endurance29%
Z3
Tempo15%
Z4
Threshold5%
Z5
VO₂max29%
Pace
Z1
Easy32%
Z2
Endurance13%
Z3
Tempo42%
Z4
Threshold12%
Z5
VO₂max0%
Z6
Speed0%
Power
Z1
Recovery1%
Z2
Endurance29%
Z3
Tempo14%
Z4
Threshold41%
Z5
VO₂max12%
Z6
Anaerobic1%
Z7
Neuro0%
Aerobic decoupling · Pa:HR-0.8%
Effort & efficiency
0.73
Running effectiveness
speed per watt/kg, reps
6.2 w/kg
Power-to-weight
rep average
2.74
Efficiency factor
norm. power per bpm
1.04
Variability index
1.0 = perfectly even power
0.5%
Rep consistency
pace spread across reps, lower is tighter
1572 kJ
Total work
mechanical energy
925 kcal
Energy
estimated burn
740 bpk
Cardiac cost
heartbeats per km
35%
Above threshold
≥ 164 bpm (Z4+)
-0:27/km
Split balance
negative split, faster 2nd half
Conditions-adjusted pace24°C · +44 m
Actual
3:44/km
Grade-adjusted
3:44/km
Heat-adjusted
3:36/km
−8s/km
True effort
3:36/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.