Intervalsconfidence 0.83
Herdsman ☕️
Colin Dismuke50 km / marathon build
Source: own Strava export
Intervals
Herdsman ☕️
Distance
19.6 km
Moving
95:12
Rep pace
3:42/km
Avg HR
149 bpm
Reps
5
Planned vs actual · TrainingPeaksPlanned 16.0 kmRan 1:35:12 · 19.6 kmIF 1.27TSS 254
Shape of the sessionEasyWorkFastest
warm up
cool down
0:005 × work / float95:12
The decode
This was a five-rep interval session. The changing work and recovery durations made it a variable rep set rather than a uniform interval block.
The pace moved from 3:35/km to 3:53/km across the five work intervals, while heart rate stayed between 167 and 172. The set did not hold pace, but the effort remained tightly grouped.
Rep splits
| Rep | Time | Pace | HR | Float |
|---|---|---|---|---|
| 1 | 4:00 | 3:35/km | 167 | 2:00 |
| 2 | 3:00 | 3:36/km | 171 | 1:30 |
| 3 | 3:00 | 3:43/km | 170 | 1:30 |
| 4 | 4:00 | 3:45/km | 172 | 2:00 |
| 5 | 5:00 | 3:53/km | 170 | 3:24 |
0.83
confidence
What the engine saw
- 5 work intervals detected from lap markers, confirmed by clear pace separation.
- Recoveries average 125s.
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
Recovery35%
Z2
Endurance39%
Z3
Tempo6%
Z4
Threshold10%
Z5
VO₂max10%
Pace
Z1
Easy76%
Z2
Endurance6%
Z3
Tempo10%
Z4
Threshold8%
Z5
VO₂max0%
Z6
Speed0%
Power
Z1
Recovery3%
Z2
Endurance37%
Z3
Tempo33%
Z4
Threshold22%
Z5
VO₂max4%
Z6
Anaerobic0%
Z7
Neuro0%
Aerobic decoupling · Pa:HR+4.2%
Effort & efficiency
0.76
Running effectiveness
speed per watt/kg, reps
5.9 w/kg
Power-to-weight
rep average
2.65
Efficiency factor
norm. power per bpm
1.07
Variability index
1.0 = perfectly even power
3.0%
Rep consistency
pace spread across reps, lower is tighter
2520 kJ
Total work
mechanical energy
1386 kcal
Energy
estimated burn
862 bpk
Cardiac cost
heartbeats per km
20%
Above threshold
≥ 164 bpm (Z4+)
-0:17/km
Split balance
negative split, faster 2nd half
Conditions-adjusted pace24°C · +143 m
Actual
3:42/km
Grade-adjusted
3:42/km
Heat-adjusted
3:34/km
−8s/km
True effort
3:34/km
−8s/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.