Intervalsconfidence 0.83
6 × 1km
Colin Dismuke50 km / marathon build
Source: own Strava export
Intervals
6 × 1km
Distance
13.1 km
Moving
80:60
Rep pace
5:00/km
Avg HR
160 bpm
Reps
6
Shape of the sessionEasyWorkFastest
cool down
0:006 × work / float80:60
The decode
The session was six 1km intervals, with work averaging 4:59/km and recoveries averaging 439s.
The reps ranged from 5:30/km to 4:40/km. Heart rate rose from 133 to 161 across the set, which finished at 4:59/km.
Rep splits
| Rep | Time | Pace | HR | Float |
|---|---|---|---|---|
| 1 | 5:08 | 5:08/km | 133 | — |
| 2 | 4:53 | 4:53/km | 145 | — |
| 3 | 5:30 | 5:30/km | 150 | — |
| 4 | 4:40 | 4:40/km | 155 | — |
| 5 | 4:47 | 4:47/km | 157 | — |
| 6 | 4:59 | 4:59/km | 161 | 7:19 |
0.83
confidence
What the engine saw
- 6 work intervals detected from lap markers, confirmed by clear pace separation.
- Recoveries average 439s.
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
Recovery10%
Z2
Endurance33%
Z3
Tempo15%
Z4
Threshold33%
Z5
VO₂max8%
Pace
Z1
Easy70%
Z2
Endurance30%
Z3
Tempo0%
Z4
Threshold0%
Z5
VO₂max0%
Z6
Speed0%
Power
Z1
Recovery35%
Z2
Endurance26%
Z3
Tempo31%
Z4
Threshold5%
Z5
VO₂max2%
Z6
Anaerobic0%
Z7
Neuro0%
Aerobic decoupling · Pa:HR+32.9%
Effort & efficiency
0.68
Running effectiveness
speed per watt/kg, reps
4.9 w/kg
Power-to-weight
rep average
2.06
Efficiency factor
norm. power per bpm
1.12
Variability index
1.0 = perfectly even power
5.4%
Rep consistency
pace spread across reps, lower is tighter
1901 kJ
Total work
mechanical energy
1216 kcal
Energy
estimated burn
1231 bpk
Cardiac cost
heartbeats per km
41%
Above threshold
≥ 164 bpm (Z4+)
+2:05/km
Split balance
positive split, slower 2nd half
Conditions-adjusted pace23°C · +122 m
Actual
4:59/km
Grade-adjusted
4:59/km
Heat-adjusted
4:49/km
−10s/km
True effort
4:49/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.