Intervalsconfidence 0.83
8 × 900m
Colin Dismuke50 km / marathon build
Source: own Strava export
Intervals
8 × 900m
Distance
21.1 km
Moving
90:14
Rep pace
3:45/km
Avg HR
165 bpm
Reps
8
Planned vs actual · TrainingPeaksPlanned 1:25:00 · 20.5 kmRan 1:30:14 · 21.1 kmIF 1.59TSS 377
Shape of the sessionEasyWorkFastest
warm up
cool down
0:008 × work / float90:14
The decode
This was an eight-rep interval progression from the session two weeks earlier, built around 3:30 efforts and 1:30 recoveries.
The reps stayed between 3:43/km and 3:48/km. Heart rate rose from 166 to 178 while the pace held together across all eight efforts.
Rep splits
| Rep | Time | Pace | HR | Float |
|---|---|---|---|---|
| 1 | 3:30 | 3:45/km | 166 | 1:30 |
| 2 | 3:30 | 3:48/km | 176 | 1:30 |
| 3 | 3:30 | 3:44/km | 175 | 1:30 |
| 4 | 3:30 | 3:45/km | 174 | 1:30 |
| 5 | 3:30 | 3:43/km | 173 | 1:30 |
| 6 | 3:30 | 3:46/km | 175 | 1:30 |
| 7 | 3:30 | 3:44/km | 177 | 1:30 |
| 8 | 3:30 | 3:46/km | 178 | 1:30 |
0.83
confidence
What the engine saw
- 8 work intervals detected from lap markers, confirmed by clear pace separation.
- Recoveries average 90s.
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
Recovery7%
Z2
Endurance7%
Z3
Tempo28%
Z4
Threshold33%
Z5
VO₂max24%
Pace
Z1
Easy28%
Z2
Endurance29%
Z3
Tempo39%
Z4
Threshold3%
Z5
VO₂max0%
Z6
Speed0%
Power
Z1
Recovery1%
Z2
Endurance9%
Z3
Tempo32%
Z4
Threshold49%
Z5
VO₂max7%
Z6
Anaerobic1%
Z7
Neuro0%
Aerobic decoupling · Pa:HR+2.7%
Effort & efficiency
0.74
Running effectiveness
speed per watt/kg, reps
6.0 w/kg
Power-to-weight
rep average
2.61
Efficiency factor
norm. power per bpm
1.03
Variability index
1.0 = perfectly even power
0.6%
Rep consistency
pace spread across reps, lower is tighter
2290 kJ
Total work
mechanical energy
1471 kcal
Energy
estimated burn
710 bpk
Cardiac cost
heartbeats per km
57%
Above threshold
≥ 164 bpm (Z4+)
-0:09/km
Split balance
negative split, faster 2nd half
Conditions-adjusted pace29°C · +111 m
Actual
3:45/km
Grade-adjusted
3:45/km
Heat-adjusted
3:33/km
−12s/km
True effort
3:33/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.