Intervalsconfidence 0.83
5 × 1km
Colin Dismuke50 km / marathon build
Source: own Strava export
Intervals
5 × 1km
Distance
13.7 km
Moving
82:29
Rep pace
4:39/km
Avg HR
159 bpm
Reps
5
Shape of the sessionEasyWorkFastest
warm up
cool down
0:005 × work / float82:29
The decode
The session was a 5 × 1km interval set, with recoveries averaging 340s.
Rep pace moved from 4:49/km to 4:35/km, with a slower third rep at 4:46/km and the fastest fourth at 4:27/km. Heart rate rose from 135 to 157 before reading 151 on the final rep.
Rep splits
| Rep | Time | Pace | HR | Float |
|---|---|---|---|---|
| 1 | 4:49 | 4:49/km | 135 | — |
| 2 | 4:39 | 4:39/km | 142 | — |
| 3 | 4:46 | 4:46/km | 152 | — |
| 4 | 4:27 | 4:27/km | 157 | — |
| 5 | 4:35 | 4:35/km | 151 | 5:40 |
0.83
confidence
What the engine saw
- 5 work intervals detected from lap markers, confirmed by clear pace separation.
- Rep paces descend across the set (a cut-down / progression).
- Recoveries average 340s.
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
Endurance15%
Z3
Tempo24%
Z4
Threshold30%
Z5
VO₂max9%
Pace
Z1
Easy71%
Z2
Endurance29%
Z3
Tempo0%
Z4
Threshold0%
Z5
VO₂max0%
Z6
Speed0%
Power
Z1
Recovery46%
Z2
Endurance29%
Z3
Tempo14%
Z4
Threshold9%
Z5
VO₂max2%
Z6
Anaerobic0%
Z7
Neuro0%
Aerobic decoupling · Pa:HR+35.3%
Effort & efficiency
0.70
Running effectiveness
speed per watt/kg, reps
5.1 w/kg
Power-to-weight
rep average
2.11
Efficiency factor
norm. power per bpm
1.12
Variability index
1.0 = perfectly even power
2.8%
Rep consistency
pace spread across reps, lower is tighter
1849 kJ
Total work
mechanical energy
1227 kcal
Energy
estimated burn
1205 bpk
Cardiac cost
heartbeats per km
39%
Above threshold
≥ 164 bpm (Z4+)
+2:06/km
Split balance
positive split, slower 2nd half
Conditions-adjusted pace24°C · +121 m
Actual
4:39/km
Grade-adjusted
4:39/km
Heat-adjusted
4:29/km
−10s/km
True effort
4:29/km
−10s/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.