Intervalsconfidence 0.83
4 × 200m
Colin Dismuke50 km / marathon build
Source: own Strava export
Intervals
4 × 200m
Distance
17.3 km
Moving
79:00
Rep pace
3:09/km
Avg HR
153 bpm
Reps
4
Planned vs actual · TrainingPeaksPlanned 16.0 kmRan 1:19:00 · 17.3 kmIF 1.29TSS 218
Shape of the sessionEasyWorkFastest
warm up
cool down
0:004 × work / float79:00
The decode
A social run with four 30-second reps was the session's speed component. The 30-second recoveries kept the work compact and continuous without turning it into a sustained interval set.
The reps held closely at 3:08/km, 3:07/km, 3:14/km and 3:08/km, while heart rate settled at 172, 175, 175 and 175. Recovery heart rate remained elevated at 178, 178 and 179, so the block maintained its load despite the short duration.
Rep splits
| Rep | Time | Pace | HR | Float |
|---|---|---|---|---|
| 1 | 0:30 | 3:08/km | 172 | 0:30 |
| 2 | 0:30 | 3:07/km | 175 | 0:30 |
| 3 | 0:30 | 3:14/km | 175 | 0:30 |
| 4 | 0:30 | 3:08/km | 175 | 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
Recovery22%
Z2
Endurance39%
Z3
Tempo11%
Z4
Threshold14%
Z5
VO₂max14%
Pace
Z1
Easy55%
Z2
Endurance30%
Z3
Tempo4%
Z4
Threshold3%
Z5
VO₂max6%
Z6
Speed2%
Power
Z1
Recovery5%
Z2
Endurance23%
Z3
Tempo44%
Z4
Threshold20%
Z5
VO₂max9%
Z6
Anaerobic0%
Z7
Neuro0%
Aerobic decoupling · Pa:HR-0.3%
Effort & efficiency
0.89
Running effectiveness
speed per watt/kg, reps
5.9 w/kg
Power-to-weight
rep average
2.63
Efficiency factor
norm. power per bpm
1.06
Variability index
1.0 = perfectly even power
1.5%
Rep consistency
pace spread across reps, lower is tighter
2192 kJ
Total work
mechanical energy
1225 kcal
Energy
estimated burn
843 bpk
Cardiac cost
heartbeats per km
28%
Above threshold
≥ 164 bpm (Z4+)
-0:18/km
Split balance
negative split, faster 2nd half
Conditions-adjusted pace17°C · +128 m
Actual
3:09/km
Grade-adjusted
3:09/km
Heat-adjusted
3:08/km
−1s/km
True effort
3:08/km
−1s/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.