Intervalsconfidence 0.88
Herdsman Intervals ☕️
Colin Dismuke50 km / marathon build
Source: own Strava export
Intervals
Herdsman Intervals ☕️
Distance
9.8 km
Moving
44:55
Rep pace
3:30/km
Avg HR
158 bpm
Reps
6
Planned vs actual · TrainingPeaksPlanned not setRan 44:55 · 9.8 kmIF 1.38TSS 141
Shape of the sessionEasyWorkFastest
warm up
cool down
0:006 × work / float44:55
The decode
A six-rep cut-down interval set was built around changing work durations and short recoveries. It demanded repeated fast efforts with limited recovery between bouts, then a faster finish rather than a fade.
The work held tightly through the middle at 3:33/km, 3:34/km and 3:34/km before closing in 3:30/km and 3:16/km. Heart rate rose from 163 on the first rep to 174 on the last, with a maximum of 184.
Rep splits
| Rep | Time | Pace | HR | Float |
|---|---|---|---|---|
| 1 | 2:00 | 3:30/km | 163 | 1:00 |
| 2 | 3:00 | 3:33/km | 169 | 1:00 |
| 3 | 4:00 | 3:34/km | 172 | 2:00 |
| 4 | 4:00 | 3:34/km | 173 | 2:00 |
| 5 | 3:00 | 3:30/km | 170 | 1:00 |
| 6 | 2:00 | 3:16/km | 174 | 1:00 |
0.88
confidence
What the engine saw
- 6 work intervals detected from lap markers, confirmed by clear pace separation.
- Rep paces descend across the set (a cut-down / progression).
- Recoveries average 80s.
- Matches the athlete's own session label.
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
Recovery30%
Z2
Endurance12%
Z3
Tempo8%
Z4
Threshold24%
Z5
VO₂max26%
Pace
Z1
Easy49%
Z2
Endurance1%
Z3
Tempo4%
Z4
Threshold41%
Z5
VO₂max3%
Z6
Speed3%
Power
Z1
Recovery17%
Z2
Endurance27%
Z3
Tempo7%
Z4
Threshold25%
Z5
VO₂max24%
Z6
Anaerobic0%
Z7
Neuro0%
Aerobic decoupling · Pa:HR+6.3%
Effort & efficiency
0.76
Running effectiveness
speed per watt/kg, reps
6.3 w/kg
Power-to-weight
rep average
2.68
Efficiency factor
norm. power per bpm
1.14
Variability index
1.0 = perfectly even power
2.9%
Rep consistency
pace spread across reps, lower is tighter
1002 kJ
Total work
mechanical energy
685 kcal
Energy
estimated burn
723 bpk
Cardiac cost
heartbeats per km
50%
Above threshold
≥ 164 bpm (Z4+)
-0:02/km
Split balance
negative split, faster 2nd half
Conditions-adjusted pace25°C · +21 m
Actual
3:29/km
Grade-adjusted
3:29/km
Heat-adjusted
3:21/km
−8s/km
True effort
3:21/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.