Intervalsconfidence 0.88
9 × 1km
Colin Dismuke50 km / marathon build
Source: own Strava export
Intervals
9 × 1km
Distance
15.6 km
Moving
67:09
Rep pace
3:45/km
Avg HR
162 bpm
Reps
9
Planned vs actual · TrainingPeaksPlanned 14.0 kmRan 1:07:09 · 15.6 kmIF 1.35TSS 203
Shape of the sessionEasyWorkFastest
warm up
cool down
0:009 × work / float67:09
The decode
This was a nine-repetition 1km threshold set, moving from just below threshold through threshold to just above threshold in three-repetition blocks, with one-minute static recoveries.
The reps ran 4:01, 3:47 and 3:36/km in the first block, 3:58, 3:43 and 3:37/km in the second, then 3:45, 3:46 and 3:36/km. Heart rate rose from 163 on rep one to 178 on rep nine, with the final rep matching the session's fastest pace.
Rep splits
| Rep | Time | Pace | HR | Float |
|---|---|---|---|---|
| 1 | 4:01 | 4:01/km | 163 | 1:00 |
| 2 | 3:47 | 3:47/km | 171 | 1:00 |
| 3 | 3:36 | 3:36/km | 174 | 1:00 |
| 4 | 3:58 | 3:58/km | 168 | 1:00 |
| 5 | 3:43 | 3:43/km | 167 | 1:00 |
| 6 | 3:37 | 3:37/km | 176 | 1:00 |
| 7 | 3:45 | 3:45/km | 174 | 1:00 |
| 8 | 3:46 | 3:46/km | 176 | 1:00 |
| 9 | 3:36 | 3:36/km | 178 | 1:00 |
0.88
confidence
What the engine saw
- 9 work intervals detected from lap markers, confirmed by clear pace separation.
- Recoveries average 60s.
- 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
Recovery13%
Z2
Endurance14%
Z3
Tempo17%
Z4
Threshold32%
Z5
VO₂max24%
Pace
Z1
Easy44%
Z2
Endurance10%
Z3
Tempo33%
Z4
Threshold12%
Z5
VO₂max1%
Z6
Speed0%
Power
Z1
Recovery1%
Z2
Endurance30%
Z3
Tempo22%
Z4
Threshold43%
Z5
VO₂max4%
Z6
Anaerobic0%
Z7
Neuro0%
Aerobic decoupling · Pa:HR+4.2%
Effort & efficiency
0.76
Running effectiveness
speed per watt/kg, reps
5.8 w/kg
Power-to-weight
rep average
2.55
Efficiency factor
norm. power per bpm
1.04
Variability index
1.0 = perfectly even power
3.8%
Rep consistency
pace spread across reps, lower is tighter
1647 kJ
Total work
mechanical energy
1088 kcal
Energy
estimated burn
715 bpk
Cardiac cost
heartbeats per km
56%
Above threshold
≥ 164 bpm (Z4+)
-0:12/km
Split balance
negative split, faster 2nd half
Conditions-adjusted pace24°C · +30 m
Actual
3:45/km
Grade-adjusted
3:45/km
Heat-adjusted
3:37/km
−8s/km
True effort
3:37/km
−8s/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.