Intervalsconfidence 0.83
6 × 1.4km
Colin Dismuke50 km / marathon build
Source: own Strava export
Intervals
6 × 1.4km
Distance
25.0 km
Moving
108:00
Rep pace
3:39/km
Avg HR
167 bpm
Reps
6
Planned vs actual · TrainingPeaksPlanned 1:10:00 · 15.8 kmRan 1:48:00 · 25.0 kmIF 1.40TSS 349
Shape of the sessionEasyWorkFastest
warm up
cool down
0:006 × work / float108:00
The decode
It was a six-repetition threshold set: six 5-minute efforts with 1:00 recoveries, followed by an extended 47:00 cooldown.
The work stayed tightly grouped at 3:40, 3:40, 3:39, 3:41, 3:35 and 3:40/km. Heart rate was 182, 180, 181, 179, 175 and 182, with the fastest repetition fifth and no late fade.
Rep splits
| Rep | Time | Pace | HR | Float |
|---|---|---|---|---|
| 1 | 5:00 | 3:40/km | 182 | 1:00 |
| 2 | 5:00 | 3:40/km | 180 | 1:00 |
| 3 | 5:00 | 3:39/km | 181 | 1:00 |
| 4 | 5:00 | 3:41/km | 179 | 1:00 |
| 5 | 5:00 | 3:35/km | 175 | 1:00 |
| 6 | 5:00 | 3:40/km | 182 | 1:00 |
0.83
confidence
What the engine saw
- 6 work intervals detected from lap markers, confirmed by clear pace separation.
- Recoveries average 60s.
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
Recovery3%
Z2
Endurance10%
Z3
Tempo26%
Z4
Threshold26%
Z5
VO₂max34%
Pace
Z1
Easy29%
Z2
Endurance41%
Z3
Tempo14%
Z4
Threshold15%
Z5
VO₂max0%
Z6
Speed0%
Power
Z1
Recovery0%
Z2
Endurance6%
Z3
Tempo56%
Z4
Threshold20%
Z5
VO₂max13%
Z6
Anaerobic5%
Z7
Neuro0%
Aerobic decoupling · Pa:HR+5.9%
Effort & efficiency
0.71
Running effectiveness
speed per watt/kg, reps
6.4 w/kg
Power-to-weight
rep average
2.58
Efficiency factor
norm. power per bpm
1.04
Variability index
1.0 = perfectly even power
0.9%
Rep consistency
pace spread across reps, lower is tighter
2819 kJ
Total work
mechanical energy
1808 kcal
Energy
estimated burn
757 bpk
Cardiac cost
heartbeats per km
60%
Above threshold
≥ 164 bpm (Z4+)
+0:15/km
Split balance
positive split, slower 2nd half
Conditions-adjusted pace21°C · +121 m
Actual
3:39/km
Grade-adjusted
3:39/km
Heat-adjusted
3:34/km
−5s/km
True effort
3:34/km
−5s/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.