Intervalsconfidence 0.83
8 × 1km
Colin Dismuke50 km / marathon build
Source: own Strava export
Intervals
8 × 1km
Distance
15.9 km
Moving
70:43
Rep pace
3:30/km
Avg HR
142 bpm
Reps
8
Planned vs actual · TrainingPeaksPlanned 1:05:52 · 14.6 kmRan 1:10:43 · 15.9 kmIF 1.57TSS 287
Shape of the sessionEasyWorkFastest
warm up
cool down
0:008 × work / float70:43
The decode
Eight 1km repeats with 60s static recoveries formed a controlled threshold set. The headwind in the last 400m of every rep made the closing section the constraint, while the static recoveries limited the reset between efforts.
The pace slowed from 3:20/km on the opening rep to 3:35/km on the final two, moving outside the intended 3:20-3:25/km range. Heart rate rose from 137 to 148, with the peak of 149 arriving on the third rep rather than at the finish.
Rep splits
| Rep | Time | Pace | HR | Float |
|---|---|---|---|---|
| 1 | 3:20 | 3:20/km | 137 | 1:00 |
| 2 | 3:28 | 3:28/km | 138 | 1:00 |
| 3 | 3:27 | 3:27/km | 149 | 1:00 |
| 4 | 3:28 | 3:28/km | 144 | 1:00 |
| 5 | 3:32 | 3:32/km | 142 | 1:00 |
| 6 | 3:33 | 3:33/km | 142 | 1:00 |
| 7 | 3:35 | 3:35/km | 146 | 1:00 |
| 8 | 3:35 | 3:35/km | 148 | 1:00 |
0.83
confidence
What the engine saw
- 8 work intervals detected from lap markers, confirmed by clear pace separation.
- Recoveries average 60s.
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
Recovery50%
Z2
Endurance45%
Z3
Tempo5%
Z4
Threshold0%
Z5
VO₂max0%
Pace
Z1
Easy27%
Z2
Endurance34%
Z3
Tempo2%
Z4
Threshold27%
Z5
VO₂max9%
Z6
Speed0%
Power
Z1
Recovery15%
Z2
Endurance5%
Z3
Tempo25%
Z4
Threshold34%
Z5
VO₂max20%
Z6
Anaerobic0%
Z7
Neuro0%
Aerobic decoupling · Pa:HR+10.2%
Effort & efficiency
0.77
Running effectiveness
speed per watt/kg, reps
6.2 w/kg
Power-to-weight
rep average
3.04
Efficiency factor
norm. power per bpm
1.11
Variability index
1.0 = perfectly even power
2.3%
Rep consistency
pace spread across reps, lower is tighter
1700 kJ
Total work
mechanical energy
1044 kcal
Energy
estimated burn
650 bpk
Cardiac cost
heartbeats per km
0%
Above threshold
≥ 164 bpm (Z4+)
+0:11/km
Split balance
positive split, slower 2nd half
Conditions-adjusted pace13°C · +160 m
Actual
3:29/km
Grade-adjusted
3:29/km
Heat-adjusted
3:29/km
True effort
3:29/km
The rep pace re-expressed for flat ground and cool air, the effort, not the clock. Adjustments are modest on this one; on a hot day or a hilly route this is where the real work hides.