Intervalsconfidence 0.83
4 × 100m
Colin Dismuke50 km / marathon build
Source: own Strava export
Intervals
4 × 100m
Distance
8.0 km
Moving
37:38
Rep pace
3:24/km
Avg HR
150 bpm
Reps
4
Planned vs actual · TrainingPeaksPlanned 8.0 kmRan 37:38 · 8.0 kmIF 1.22TSS 92
Shape of the sessionEasyWorkFastest
warm up
cool down
0:004 × work / float37:38
The decode
A jog with 30-second strides was a controlled acceleration session, with efforts intended to build from 60% to 90%. The short duration kept the demand neuromuscular rather than sustained.
The four recorded efforts were uneven in speed but held together after the 3:16/km second rep, finishing at 3:24/km and 3:28/km. Heart rate rose from 161 to 171 across the work reps.
Rep splits
| Rep | Time | Pace | HR | Float |
|---|---|---|---|---|
| 1 | 0:30 | 3:27/km | 161 | 0:30 |
| 2 | 0:30 | 3:16/km | 168 | 0:30 |
| 3 | 0:30 | 3:24/km | 171 | 0:30 |
| 4 | 0:30 | 3:28/km | 171 | 0:30 |
0.83
confidence
What the engine saw
- 4 work intervals detected from lap markers, confirmed by clear pace separation.
- Recoveries average 30s.
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
Recovery41%
Z2
Endurance13%
Z3
Tempo14%
Z4
Threshold29%
Z5
VO₂max3%
Pace
Z1
Easy64%
Z2
Endurance13%
Z3
Tempo11%
Z4
Threshold10%
Z5
VO₂max2%
Z6
Speed0%
Power
Z1
Recovery1%
Z2
Endurance53%
Z3
Tempo23%
Z4
Threshold11%
Z5
VO₂max12%
Z6
Anaerobic0%
Z7
Neuro0%
Aerobic decoupling · Pa:HR+3.4%
Effort & efficiency
0.96
Running effectiveness
speed per watt/kg, reps
5.1 w/kg
Power-to-weight
rep average
2.59
Efficiency factor
norm. power per bpm
1.05
Variability index
1.0 = perfectly even power
2.4%
Rep consistency
pace spread across reps, lower is tighter
836 kJ
Total work
mechanical energy
566 kcal
Energy
estimated burn
704 bpk
Cardiac cost
heartbeats per km
32%
Above threshold
≥ 164 bpm (Z4+)
-0:23/km
Split balance
negative split, faster 2nd half
Conditions-adjusted pace19°C · +7 m
Actual
3:24/km
Grade-adjusted
3:24/km
Heat-adjusted
3:21/km
−3s/km
True effort
3:21/km
−3s/km
The rep pace re-expressed for flat ground and cool air, the effort, not the clock. Adjustments are modest on this one; on a hot day or a hilly route this is where the real work hides.