Intervalsconfidence 0.83
3 × 5km
Colin Dismuke50 km / marathon build
Source: own Strava export
Intervals
3 × 5km
Distance
18.8 km
Moving
80:49
Rep pace
3:56/km
Avg HR
164 bpm
Reps
3
Planned vs actual · TrainingPeaksPlanned 1:18:52 · 18.5 kmRan 1:20:49 · 18.8 kmIF 1.39TSS 259
Shape of the sessionEasyWorkFastest
warm up
cool down
0:003 × work / float80:49
The decode
It was a sub-threshold set of three 5km repetitions, with 3-minute walk-or-jog recoveries between them.
The work progressed from 3:58/km to 3:56/km to 3:55/km. Heart rate rose from 168 to 174 to 175, while the set held together.
Rep splits
| Rep | Time | Pace | HR | Float |
|---|---|---|---|---|
| 1 | 19:51 | 3:58/km | 168 | 3:00 |
| 2 | 19:41 | 3:56/km | 174 | 3:00 |
| 3 | 19:35 | 3:55/km | 175 | 0:53 |
0.83
confidence
What the engine saw
- 3 work intervals detected from lap markers, confirmed by clear pace separation.
- Recoveries average 138s.
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
Recovery17%
Z2
Endurance4%
Z3
Tempo8%
Z4
Threshold37%
Z5
VO₂max34%
Pace
Z1
Easy21%
Z2
Endurance9%
Z3
Tempo70%
Z4
Threshold0%
Z5
VO₂max0%
Z6
Speed0%
Power
Z1
Recovery7%
Z2
Endurance9%
Z3
Tempo14%
Z4
Threshold68%
Z5
VO₂max1%
Z6
Anaerobic0%
Z7
Neuro0%
Aerobic decoupling · Pa:HR+6.4%
Effort & efficiency
0.73
Running effectiveness
speed per watt/kg, reps
5.8 w/kg
Power-to-weight
rep average
2.57
Efficiency factor
norm. power per bpm
1.05
Variability index
1.0 = perfectly even power
0.6%
Rep consistency
pace spread across reps, lower is tighter
1970 kJ
Total work
mechanical energy
1316 kcal
Energy
estimated burn
713 bpk
Cardiac cost
heartbeats per km
71%
Above threshold
≥ 164 bpm (Z4+)
-0:06/km
Split balance
negative split, faster 2nd half
Conditions-adjusted pace30°C · +45 m
Actual
3:56/km
Grade-adjusted
3:56/km
Heat-adjusted
3:43/km
−13s/km
True effort
3:43/km
−13s/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.