Intervalsconfidence 0.83
Lunch Run
Colin Dismuke50 km / marathon build
Source: own Strava export
Intervals
Lunch Run
Distance
12.3 km
Moving
52:15
Rep pace
3:45/km
Avg HR
167 bpm
Reps
3
Planned vs actual · TrainingPeaksPlanned 1:06:27 · 14.4 kmRan 52:15 · 12.3 kmIF 1.64TSS 233
Shape of the sessionEasyWorkFastest
warm up
cool down
0:003 × work / float52:15
The decode
A threshold set of 3k, 3k and 2k demanded sustained work with short rests rather than a single continuous effort. The heat made the repeated threshold work more costly than the structure suggested.
The pace drifted from 3:40/km to 3:45/km to 3:50/km, while heart rate rose from 176 to 180 and then held at 180. The set slowed, but the final effort maintained the elevated heart-rate load.
Rep splits
| Rep | Time | Pace | HR | Float |
|---|---|---|---|---|
| 1 | 11:00 | 3:40/km | 176 | 2:00 |
| 2 | 11:14 | 3:45/km | 180 | 2:00 |
| 3 | 7:40 | 3:50/km | 180 | 0:60 |
0.83
confidence
What the engine saw
- 3 work intervals detected from lap markers, confirmed by clear pace separation.
- Recoveries average 100s.
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
Recovery8%
Z2
Endurance28%
Z3
Tempo6%
Z4
Threshold14%
Z5
VO₂max43%
Pace
Z1
Easy18%
Z2
Endurance29%
Z3
Tempo42%
Z4
Threshold11%
Z5
VO₂max0%
Z6
Speed0%
Power
Z1
Recovery13%
Z2
Endurance6%
Z3
Tempo22%
Z4
Threshold34%
Z5
VO₂max22%
Z6
Anaerobic2%
Z7
Neuro0%
Aerobic decoupling · Pa:HR+13.2%
Effort & efficiency
0.70
Running effectiveness
speed per watt/kg, reps
6.3 w/kg
Power-to-weight
rep average
2.66
Efficiency factor
norm. power per bpm
1.07
Variability index
1.0 = perfectly even power
1.8%
Rep consistency
pace spread across reps, lower is tighter
1356 kJ
Total work
mechanical energy
924 kcal
Energy
estimated burn
757 bpk
Cardiac cost
heartbeats per km
57%
Above threshold
≥ 164 bpm (Z4+)
+0:25/km
Split balance
positive split, slower 2nd half
Conditions-adjusted pace34°C · +60 m
Actual
3:45/km
Grade-adjusted
3:45/km
Heat-adjusted
3:29/km
−16s/km
True effort
3:29/km
−16s/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.