Intervalsconfidence 0.83
Lunch Run
Colin Dismuke50 km / marathon build
Source: own Strava export
Intervals
Lunch Run
Distance
10.8 km
Moving
53:17
Rep pace
4:37/km
Avg HR
158 bpm
Reps
5
Shape of the sessionEasyWorkFastest
warm up
0:005 × work / float53:17
The decode
A five-rep interval session was defined by clear pace separation and extended recoveries averaging 302 seconds. It demanded repeated changes of pace without the continuity of a sustained effort.
The reps moved from 4:41/km to 4:33/km, 4:38/km and 4:44/km before closing at 4:30/km over 751 m. Heart rate rose from 149 to 172, then finished at 168, with the set recovering its pace late.
Rep splits
| Rep | Time | Pace | HR | Float |
|---|---|---|---|---|
| 1 | 4:41 | 4:41/km | 149 | 5:02 |
| 2 | 4:33 | 4:33/km | 161 | — |
| 3 | 4:38 | 4:38/km | 162 | — |
| 4 | 4:44 | 4:44/km | 172 | — |
| 5 | 3:23 | 4:30/km | 168 | — |
0.83
confidence
What the engine saw
- 5 work intervals detected from lap markers, confirmed by clear pace separation.
- Recoveries average 302s.
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
Recovery12%
Z2
Endurance19%
Z3
Tempo28%
Z4
Threshold39%
Z5
VO₂max2%
Pace
Z1
Easy66%
Z2
Endurance33%
Z3
Tempo0%
Z4
Threshold0%
Z5
VO₂max0%
Z6
Speed0%
Power
Z1
Recovery3%
Z2
Endurance31%
Z3
Tempo38%
Z4
Threshold21%
Z5
VO₂max6%
Z6
Anaerobic0%
Z7
Neuro0%
Aerobic decoupling · Pa:HR+3.6%
Effort & efficiency
0.74
Running effectiveness
speed per watt/kg, reps
4.9 w/kg
Power-to-weight
rep average
2.47
Efficiency factor
norm. power per bpm
1.04
Variability index
1.0 = perfectly even power
1.9%
Rep consistency
pace spread across reps, lower is tighter
1250 kJ
Total work
mechanical energy
796 kcal
Energy
estimated burn
812 bpk
Cardiac cost
heartbeats per km
41%
Above threshold
≥ 164 bpm (Z4+)
-0:16/km
Split balance
negative split, faster 2nd half
Conditions-adjusted pace30°C · +264 m
Actual
4:37/km
Grade-adjusted
4:37/km
Heat-adjusted
4:21/km
−16s/km
True effort
4:21/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.