Intervalsconfidence 0.83
Afternoon Run
Colin Dismuke50 km / marathon build
Source: own Strava export
Intervals
Afternoon Run
Distance
12.2 km
Moving
51:06
Rep pace
3:54/km
Avg HR
166 bpm
Reps
5
Planned vs actual · TrainingPeaksPlanned 1:12:51 · 17.0 kmRan 51:06 · 12.2 kmIF 1.59TSS 218
Shape of the sessionEasyWorkFastest
warm up
cool down
0:005 × work / float51:06
The decode
An adapted 2 x 2 km plus 1 km threshold set was built to carry controlled work from longer efforts into shorter repetitions. The longer opening efforts made the later repetitions a continuation of accumulated load, while the jog recoveries limited the reset between efforts.
The 1 km work ran at 3:50/km, 3:58/km, 3:56/km for 814 m, 3:55/km and 3:49/km. Heart rate moved from 177 and 176 to 168, then 174 and 175; the final 1 km was the fastest after only 0:27 recovery, so the set held together.
Rep splits
| Rep | Time | Pace | HR | Float |
|---|---|---|---|---|
| 1 | 3:50 | 3:50/km | 177 | 1:00 |
| 2 | 3:58 | 3:58/km | 176 | 1:00 |
| 3 | 3:12 | 3:56/km | 168 | 1:00 |
| 4 | 3:55 | 3:55/km | 174 | 1:00 |
| 5 | 3:49 | 3:49/km | 175 | 0:27 |
0.83
confidence
What the engine saw
- 5 work intervals detected from lap markers, confirmed by clear pace separation.
- Recoveries average 53s.
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
Recovery7%
Z2
Endurance9%
Z3
Tempo10%
Z4
Threshold28%
Z5
VO₂max45%
Pace
Z1
Easy30%
Z2
Endurance10%
Z3
Tempo60%
Z4
Threshold0%
Z5
VO₂max0%
Z6
Speed0%
Power
Z1
Recovery6%
Z2
Endurance7%
Z3
Tempo28%
Z4
Threshold47%
Z5
VO₂max11%
Z6
Anaerobic0%
Z7
Neuro0%
Aerobic decoupling · Pa:HR+3.4%
Effort & efficiency
0.73
Running effectiveness
speed per watt/kg, reps
5.9 w/kg
Power-to-weight
rep average
2.64
Efficiency factor
norm. power per bpm
1.04
Variability index
1.0 = perfectly even power
1.5%
Rep consistency
pace spread across reps, lower is tighter
1465 kJ
Total work
mechanical energy
875 kcal
Energy
estimated burn
806 bpk
Cardiac cost
heartbeats per km
74%
Above threshold
≥ 164 bpm (Z4+)
+0:03/km
Split balance
positive split, slower 2nd half
Conditions-adjusted pace31°C · +56 m
Actual
3:54/km
Grade-adjusted
3:54/km
Heat-adjusted
3:40/km
−14s/km
True effort
3:40/km
−14s/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.