Intervalsconfidence 0.83
6 × 600m
Colin Dismuke50 km / marathon build
Source: own Strava export
Intervals
6 × 600m
Distance
8.2 km
Moving
41:28
Rep pace
3:27/km
Avg HR
148 bpm
Reps
6
Shape of the sessionEasyWorkFastest
warm up
cool down
0:006 × work / float41:28
The decode
It was a six-round interval set pairing 600m reps with 200m efforts. The 600m reps were separated from the 200m efforts by 30s recoveries, with 2:00 recoveries between rounds.
The 600m reps ran in 2:01, 2:04, 2:07, 2:05, 2:05 and 2:02, equivalent to 3:22/km through 3:31/km. The 200m efforts ran from 2:54/km to 3:15/km, and heart rate reached 163 on the final 600m.
Rep splits
| Rep | Time | Pace | HR | Float |
|---|---|---|---|---|
| 1 | 2:01 | 3:22/km | 152 | 0:30 |
| 2 | 2:04 | 3:27/km | 146 | 0:30 |
| 3 | 2:07 | 3:31/km | 152 | 0:30 |
| 4 | 2:05 | 3:29/km | 149 | 0:30 |
| 5 | 2:05 | 3:29/km | 151 | 0:30 |
| 6 | 2:02 | 3:24/km | 163 | 0:30 |
0.83
confidence
What the engine saw
- 6 work intervals detected from lap markers, confirmed by clear pace separation.
- Recoveries average 30s.
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
Recovery42%
Z2
Endurance17%
Z3
Tempo19%
Z4
Threshold20%
Z5
VO₂max3%
Pace
Z1
Easy59%
Z2
Endurance0%
Z3
Tempo3%
Z4
Threshold9%
Z5
VO₂max18%
Z6
Speed10%
Power
Z1
Recovery28%
Z2
Endurance30%
Z3
Tempo0%
Z4
Threshold14%
Z5
VO₂max17%
Z6
Anaerobic11%
Z7
Neuro0%
Aerobic decoupling · Pa:HR-0.9%
Effort & efficiency
0.74
Running effectiveness
speed per watt/kg, reps
6.5 w/kg
Power-to-weight
rep average
2.83
Efficiency factor
norm. power per bpm
1.21
Variability index
1.0 = perfectly even power
1.6%
Rep consistency
pace spread across reps, lower is tighter
860 kJ
Total work
mechanical energy
585 kcal
Energy
estimated burn
747 bpk
Cardiac cost
heartbeats per km
22%
Above threshold
≥ 164 bpm (Z4+)
-0:26/km
Split balance
negative split, faster 2nd half
Conditions-adjusted pace22°C · +17 m
Actual
3:27/km
Grade-adjusted
3:27/km
Heat-adjusted
3:21/km
−6s/km
True effort
3:21/km
−6s/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.