Intervalsconfidence 0.83
5 × 1km
Colin Dismuke50 km / marathon build
Source: own Strava export
Intervals
5 × 1km
Distance
20.9 km
Moving
103:05
Rep pace
3:35/km
Avg HR
145 bpm
Reps
5
Planned vs actual · TrainingPeaksPlanned 18.0 kmRan 1:43:05 · 20.9 kmIF 1.28TSS 279
Shape of the sessionEasyWorkFastest
warm up
cool down
0:005 × work / float103:05
The decode
Five 3:30 intervals off 1:30 recoveries made up the session. The long lead-in put the repetitions on preloaded legs, while the fixed recoveries limited clearance between efforts.
The first four reps held between 3:31/km and 3:34/km before the fifth fell to 3:41/km. Heart rate rose from 168 to 174 by rep four, then was 171 on the last, so the set lost pace without a further HR rise.
Rep splits
| Rep | Time | Pace | HR | Float |
|---|---|---|---|---|
| 1 | 3:30 | 3:31/km | 168 | 1:30 |
| 2 | 3:30 | 3:33/km | 172 | 1:30 |
| 3 | 3:30 | 3:34/km | 171 | 1:30 |
| 4 | 3:30 | 3:34/km | 174 | 1:30 |
| 5 | 3:30 | 3:41/km | 171 | 1:30 |
0.83
confidence
What the engine saw
- 5 work intervals detected from lap markers, confirmed by clear pace separation.
- Recoveries average 90s.
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
Recovery46%
Z2
Endurance34%
Z3
Tempo5%
Z4
Threshold8%
Z5
VO₂max8%
Pace
Z1
Easy74%
Z2
Endurance12%
Z3
Tempo3%
Z4
Threshold11%
Z5
VO₂max0%
Z6
Speed0%
Power
Z1
Recovery4%
Z2
Endurance45%
Z3
Tempo26%
Z4
Threshold15%
Z5
VO₂max9%
Z6
Anaerobic1%
Z7
Neuro0%
Aerobic decoupling · Pa:HR-3.7%
Effort & efficiency
0.73
Running effectiveness
speed per watt/kg, reps
6.4 w/kg
Power-to-weight
rep average
2.72
Efficiency factor
norm. power per bpm
1.07
Variability index
1.0 = perfectly even power
1.5%
Rep consistency
pace spread across reps, lower is tighter
2588 kJ
Total work
mechanical energy
1475 kcal
Energy
estimated burn
811 bpk
Cardiac cost
heartbeats per km
16%
Above threshold
≥ 164 bpm (Z4+)
-0:42/km
Split balance
negative split, faster 2nd half
Conditions-adjusted pace25°C · +197 m
Actual
3:34/km
Grade-adjusted
3:34/km
Heat-adjusted
3:26/km
−8s/km
True effort
3:26/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.