Intervalsconfidence 0.88
6 × 1km
Colin Dismuke50 km / marathon build
Source: own Strava export
Intervals
6 × 1km
Distance
9.9 km
Moving
46:09
Rep pace
3:34/km
Avg HR
158 bpm
Reps
6
Shape of the sessionEasyWorkFastest
warm up
cool down
0:006 × work / float46:09
The decode
Six 1km reps made up an interval set. The uneven recoveries, including two 5-second entries, made the structure less clean than the label suggested.
The first five reps stayed between 3:30/km and 3:35/km before 3:40/km on the sixth, while heart rate rose from 167 to 178. The set held close through five reps, then faded on the final rep.
Rep splits
| Rep | Time | Pace | HR | Float |
|---|---|---|---|---|
| 1 | 3:34 | 3:34/km | 167 | 1:30 |
| 2 | 3:30 | 3:30/km | 170 | 1:22 |
| 3 | 3:35 | 3:35/km | 173 | 0:05 |
| 4 | 3:31 | 3:31/km | 171 | 0:05 |
| 5 | 3:33 | 3:33/km | 173 | 1:38 |
| 6 | 3:40 | 3:40/km | 178 | 6:00 |
0.88
confidence
What the engine saw
- 6 work intervals detected from lap markers, confirmed by clear pace separation.
- Recoveries average 107s.
- Matches the athlete's own session label.
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
Recovery24%
Z2
Endurance25%
Z3
Tempo10%
Z4
Threshold10%
Z5
VO₂max32%
Pace
Z1
Easy51%
Z2
Endurance7%
Z3
Tempo8%
Z4
Threshold27%
Z5
VO₂max6%
Z6
Speed1%
Power
Z1
Recovery18%
Z2
Endurance12%
Z3
Tempo23%
Z4
Threshold34%
Z5
VO₂max14%
Z6
Anaerobic0%
Z7
Neuro0%
Aerobic decoupling · Pa:HR+10.1%
Effort & efficiency
0.77
Running effectiveness
speed per watt/kg, reps
6.1 w/kg
Power-to-weight
rep average
2.65
Efficiency factor
norm. power per bpm
1.13
Variability index
1.0 = perfectly even power
1.4%
Rep consistency
pace spread across reps, lower is tighter
1151 kJ
Total work
mechanical energy
674 kcal
Energy
estimated burn
826 bpk
Cardiac cost
heartbeats per km
42%
Above threshold
≥ 164 bpm (Z4+)
+0:08/km
Split balance
positive split, slower 2nd half
Conditions-adjusted pace29°C · +34 m
Actual
3:34/km
Grade-adjusted
3:34/km
Heat-adjusted
3:22/km
−12s/km
True effort
3:22/km
−12s/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.