Intervalsconfidence 0.83
4 × 600m
Colin Dismuke50 km / marathon build
Source: own Strava export
Intervals
4 × 600m
Distance
11.4 km
Moving
50:31
Rep pace
3:30/km
Avg HR
139 bpm
Reps
4
Planned vs actual · TrainingPeaksPlanned 48:00 · 10.8 kmRan 50:31 · 11.4 kmIF 1.49TSS 185
Shape of the sessionEasyWorkFastest
warm up
cool down
0:004 × work / float50:31
The decode
This was a power-focused activation built around four 2:00 interval efforts, with 2:00 recoveries and 0:30 steady segments in the sequence.
The efforts moved from 3:36/km to 3:28/km, held at 3:28/km, then finished at 3:29/km despite a slight headwind and tired legs. Heart rate rose from 136 to 168 while the pace held together.
Rep splits
| Rep | Time | Pace | HR | Float |
|---|---|---|---|---|
| 1 | 2:00 | 3:36/km | 136 | 2:00 |
| 2 | 2:00 | 3:28/km | 136 | 2:00 |
| 3 | 2:00 | 3:28/km | 154 | 2:00 |
| 4 | 2:00 | 3:29/km | 168 | 2:00 |
0.83
confidence
What the engine saw
- 4 work intervals detected from lap markers, confirmed by clear pace separation.
- Rep paces descend across the set (a cut-down / progression).
- Recoveries average 120s.
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
Recovery65%
Z2
Endurance9%
Z3
Tempo12%
Z4
Threshold14%
Z5
VO₂max0%
Pace
Z1
Easy52%
Z2
Endurance28%
Z3
Tempo3%
Z4
Threshold12%
Z5
VO₂max3%
Z6
Speed1%
Power
Z1
Recovery1%
Z2
Endurance13%
Z3
Tempo54%
Z4
Threshold21%
Z5
VO₂max10%
Z6
Anaerobic2%
Z7
Neuro0%
Aerobic decoupling · Pa:HR+9.8%
Effort & efficiency
0.79
Running effectiveness
speed per watt/kg, reps
6.1 w/kg
Power-to-weight
rep average
2.99
Efficiency factor
norm. power per bpm
1.03
Variability index
1.0 = perfectly even power
1.5%
Rep consistency
pace spread across reps, lower is tighter
1265 kJ
Total work
mechanical energy
733 kcal
Energy
estimated burn
641 bpk
Cardiac cost
heartbeats per km
14%
Above threshold
≥ 164 bpm (Z4+)
-0:21/km
Split balance
negative split, faster 2nd half
Conditions-adjusted pace27°C · +62 m
Actual
3:30/km
Grade-adjusted
3:30/km
Heat-adjusted
3:21/km
−9s/km
True effort
3:21/km
−9s/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.