Intervalsconfidence 0.88
6 × 600m
Colin Dismuke50 km / marathon build
Source: own Strava export
Intervals
6 × 600m
Distance
12.9 km
Moving
58:58
Rep pace
3:29/km
Avg HR
155 bpm
Reps
6
Planned vs actual · TrainingPeaksPlanned 57:06 · 12.3 kmRan 58:58 · 12.9 kmIF 1.34TSS 176
Shape of the sessionEasyWorkFastest
warm up
cool down
0:006 × work / float58:58
The decode
This was a split interval set built around six 600m reps and a 2km race-pace block. The format paired controlled running with a hard finish, then repeated it after the race-pace block; static recoveries made the transitions costly.
The second trio was slower than the first, with the 600m pace moving from 3:23/km, 3:25/km and 3:26/km to 3:31/km, 3:32/km and 3:34/km. The 2km block held 3:42/km while heart rate rose from 171 to 180.
Rep splits
| Rep | Time | Pace | HR | Float |
|---|---|---|---|---|
| 1 | 2:02 | 3:23/km | 163 | — |
| 2 | 2:03 | 3:25/km | 166 | — |
| 3 | 2:03 | 3:26/km | 169 | — |
| 4 | 2:07 | 3:31/km | 165 | — |
| 5 | 2:07 | 3:32/km | 170 | — |
| 6 | 2:08 | 3:34/km | 168 | — |
0.88
confidence
What the engine saw
- 6 work intervals detected from lap markers, confirmed by clear pace separation.
- 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
Recovery34%
Z2
Endurance24%
Z3
Tempo5%
Z4
Threshold11%
Z5
VO₂max26%
Pace
Z1
Easy58%
Z2
Endurance4%
Z3
Tempo10%
Z4
Threshold20%
Z5
VO₂max5%
Z6
Speed3%
Power
Z1
Recovery11%
Z2
Endurance20%
Z3
Tempo30%
Z4
Threshold25%
Z5
VO₂max14%
Z6
Anaerobic1%
Z7
Neuro0%
Aerobic decoupling · Pa:HR+3.6%
Effort & efficiency
0.78
Running effectiveness
speed per watt/kg, reps
6.2 w/kg
Power-to-weight
rep average
2.68
Efficiency factor
norm. power per bpm
1.08
Variability index
1.0 = perfectly even power
2.0%
Rep consistency
pace spread across reps, lower is tighter
1441 kJ
Total work
mechanical energy
915 kcal
Energy
estimated burn
754 bpk
Cardiac cost
heartbeats per km
37%
Above threshold
≥ 164 bpm (Z4+)
-0:25/km
Split balance
negative split, faster 2nd half
Conditions-adjusted pace32°C · +30 m
Actual
3:28/km
Grade-adjusted
3:28/km
Heat-adjusted
3:15/km
−13s/km
True effort
3:15/km
−13s/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.