Intervalsconfidence 0.83
Morning Run
Colin Dismuke50 km / marathon build
Source: own Strava export
Intervals
Morning Run
Distance
19.5 km
Moving
100:38
Rep pace
4:03/km
Avg HR
143 bpm
Reps
6
Planned vs actual · TrainingPeaksPlanned 18.0 kmRan 1:40:38 · 19.5 kmIF 1.31TSS 286
Shape of the sessionEasyWorkFastest
warm up
cool down
0:006 × work / float100:38
The decode
This was a six-rep interval set within a 19.49 km run. The 10,937 m lead-in and 3,382 m cooldown kept the fast work embedded in substantial aerobic volume.
The 90-second reps varied from 4:00/km to 4:17/km and 4:03/km before the 60-second reps tightened to 3:54/km and 3:57/km, then eased to 4:05/km. Heart rate rose from 138 to 149 before settling at 144, so the set remained controlled despite the late softening.
Rep splits
| Rep | Time | Pace | HR | Float |
|---|---|---|---|---|
| 1 | 1:30 | 4:00/km | 138 | 3:02 |
| 2 | 1:30 | 4:17/km | 146 | 2:59 |
| 3 | 1:30 | 4:03/km | 139 | 2:00 |
| 4 | 1:00 | 3:54/km | 149 | 2:00 |
| 5 | 1:00 | 3:57/km | 145 | 2:00 |
| 6 | 1:00 | 4:05/km | 144 | 2:00 |
0.83
confidence
What the engine saw
- 6 work intervals detected from lap markers, confirmed by clear pace separation.
- Recoveries average 140s.
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
Recovery37%
Z2
Endurance59%
Z3
Tempo4%
Z4
Threshold0%
Z5
VO₂max0%
Pace
Z1
Easy86%
Z2
Endurance10%
Z3
Tempo3%
Z4
Threshold0%
Z5
VO₂max1%
Z6
Speed0%
Power
Z1
Recovery11%
Z2
Endurance49%
Z3
Tempo16%
Z4
Threshold10%
Z5
VO₂max9%
Z6
Anaerobic5%
Z7
Neuro0%
Aerobic decoupling · Pa:HR-4.1%
Effort & efficiency
0.56
Running effectiveness
speed per watt/kg, reps
7.4 w/kg
Power-to-weight
rep average
2.84
Efficiency factor
norm. power per bpm
1.13
Variability index
1.0 = perfectly even power
3.0%
Rep consistency
pace spread across reps, lower is tighter
2668 kJ
Total work
mechanical energy
1389 kcal
Energy
estimated burn
918 bpk
Cardiac cost
heartbeats per km
0%
Above threshold
≥ 164 bpm (Z4+)
-0:01/km
Split balance
negative split, faster 2nd half
Conditions-adjusted pace16°C · +434 m
Actual
4:02/km
Grade-adjusted
4:02/km
Heat-adjusted
4:01/km
−1s/km
True effort
4:01/km
−1s/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.