Intervalsconfidence 0.83
20 × 200m
Colin Dismuke50 km / marathon build
Source: own Strava export
Intervals
20 × 200m
Distance
13.7 km
Moving
65:40
Rep pace
3:13/km
Avg HR
155 bpm
Reps
20
Shape of the sessionEasyWorkFastest
warm up
cool down
0:0020 × work / float65:40
The decode
A 20 x 200m interval set used 45s recoveries between reps.
The first 19 reps were 37-40s, followed by a 36s final repetition. Heart rate rose from 149 on rep 1 to 170 on rep 9, then the final rep registered 155.
Rep splits
| Rep | Time | Pace | HR | Float |
|---|---|---|---|---|
| 1 | 0:39 | 3:13/km | 149 | 0:45 |
| 2 | 0:38 | 3:09/km | 156 | 0:45 |
| 3 | 0:37 | 3:06/km | 159 | 0:45 |
| 4 | 0:38 | 3:11/km | 163 | 0:45 |
| 5 | 0:38 | 3:12/km | 164 | 0:45 |
| 6 | 0:39 | 3:13/km | 163 | 0:45 |
| 7 | 0:39 | 3:15/km | 162 | 0:45 |
| 8 | 0:39 | 3:15/km | 168 | 0:45 |
| 9 | 0:40 | 3:20/km | 170 | 0:45 |
| 10 | 0:39 | 3:13/km | 168 | 0:45 |
| 11 | 0:39 | 3:16/km | 168 | 0:45 |
| 12 | 0:40 | 3:21/km | 168 | 0:45 |
| 13 | 0:37 | 3:05/km | 154 | 0:45 |
| 14 | 0:40 | 3:19/km | 165 | 0:45 |
| 15 | 0:39 | 3:14/km | 161 | 0:45 |
| 16 | 0:39 | 3:16/km | 165 | 0:45 |
| 17 | 0:40 | 3:18/km | 162 | 0:45 |
| 18 | 0:38 | 3:08/km | 166 | 0:45 |
| 19 | 0:38 | 3:08/km | 166 | 0:45 |
| 20 | 0:36 | 3:01/km | 155 | 0:45 |
0.83
confidence
What the engine saw
- 20 work intervals detected from lap markers, confirmed by clear pace separation.
- Recoveries average 45s.
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
Recovery15%
Z2
Endurance24%
Z3
Tempo34%
Z4
Threshold23%
Z5
VO₂max5%
Pace
Z1
Easy51%
Z2
Endurance31%
Z3
Tempo3%
Z4
Threshold4%
Z5
VO₂max5%
Z6
Speed7%
Power
Z1
Recovery7%
Z2
Endurance29%
Z3
Tempo40%
Z4
Threshold10%
Z5
VO₂max12%
Z6
Anaerobic2%
Z7
Neuro0%
Aerobic decoupling · Pa:HR+3.5%
Effort & efficiency
0.83
Running effectiveness
speed per watt/kg, reps
6.3 w/kg
Power-to-weight
rep average
2.65
Efficiency factor
norm. power per bpm
1.11
Variability index
1.0 = perfectly even power
2.6%
Rep consistency
pace spread across reps, lower is tighter
1805 kJ
Total work
mechanical energy
977 kcal
Energy
estimated burn
914 bpk
Cardiac cost
heartbeats per km
27%
Above threshold
≥ 164 bpm (Z4+)
-0:09/km
Split balance
negative split, faster 2nd half
Conditions-adjusted pace22°C · +101 m
Actual
3:13/km
Grade-adjusted
3:13/km
Heat-adjusted
3:07/km
−6s/km
True effort
3:07/km
−6s/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.