Intervalsconfidence 0.83
4 × 200m
Colin Dismuke50 km / marathon build
Source: own Strava export
Intervals
4 × 200m
Distance
21.3 km
Moving
98:24
Rep pace
3:12/km
Avg HR
143 bpm
Reps
4
Planned vs actual · TrainingPeaksPlanned 14.0 kmRan 1:38:24 · 21.3 kmIF 1.49TSS 363
Shape of the sessionEasyWorkFastest
warm up
cool down
0:004 × work / float98:24
The decode
The session was a social group run prescribed at 12-18km, with a short interval block embedded in the run. It covered 21.27 km in total.
The four work reps covered 160m, 153m, 156m and 150m in 30s, 29s, 30s and 30s, with recoveries of 31s, 31s, 32s and 30s. Pace moved from 3:05/km to 3:13/km, 3:09/km and 3:22/km, while heart rate rose from 145 to 152.
Rep splits
| Rep | Time | Pace | HR | Float |
|---|---|---|---|---|
| 1 | 0:30 | 3:05/km | 145 | 0:31 |
| 2 | 0:29 | 3:13/km | 144 | 0:31 |
| 3 | 0:30 | 3:09/km | 147 | 0:32 |
| 4 | 0:30 | 3:22/km | 152 | 0:30 |
0.83
confidence
What the engine saw
- 4 work intervals detected from lap markers, confirmed by clear pace separation.
- Recoveries average 31s.
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
Recovery34%
Z2
Endurance66%
Z3
Tempo0%
Z4
Threshold0%
Z5
VO₂max0%
Pace
Z1
Easy35%
Z2
Endurance55%
Z3
Tempo2%
Z4
Threshold3%
Z5
VO₂max3%
Z6
Speed2%
Power
Z1
Recovery0%
Z2
Endurance21%
Z3
Tempo57%
Z4
Threshold14%
Z5
VO₂max7%
Z6
Anaerobic0%
Z7
Neuro0%
Aerobic decoupling · Pa:HR-15.9%
Effort & efficiency
0.78
Running effectiveness
speed per watt/kg, reps
6.7 w/kg
Power-to-weight
rep average
2.85
Efficiency factor
norm. power per bpm
1.04
Variability index
1.0 = perfectly even power
3.3%
Rep consistency
pace spread across reps, lower is tighter
2785 kJ
Total work
mechanical energy
1438 kcal
Energy
estimated burn
800 bpk
Cardiac cost
heartbeats per km
0%
Above threshold
≥ 164 bpm (Z4+)
-0:29/km
Split balance
negative split, faster 2nd half
Conditions-adjusted pace14°C · +167 m
Actual
3:12/km
Grade-adjusted
3:12/km
Heat-adjusted
3:12/km
True effort
3:12/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.