Intervalsconfidence 0.88
11 × 500m
Colin Dismuke50 km / marathon build
Source: own Strava export
Intervals
11 × 500m
Distance
12.0 km
Moving
59:34
Rep pace
3:48/km
Avg HR
148 bpm
Reps
11
Planned vs actual · TrainingPeaksPlanned not setRan 59:34 · 12.0 kmIF 1.32TSS 171
Shape of the sessionEasyWorkFastest
warm up
cool down
0:0011 × work / float59:34
The decode
Eleven 500m repetitions formed an interval session with 120-second recoveries. The repeated accelerations demanded speed under incomplete reset, with the 4:00/km repetition showing the cost of the middle of the set.
The set held together and closed fastest at 3:36/km. Heart rate reached 174, 175, 173, 175, 172, 174 and 176 on the faster repetitions, with the final rep carrying the highest reading.
Rep splits
| Rep | Time | Pace | HR | Float |
|---|---|---|---|---|
| 1 | 1:54 | 3:48/km | 162 | — |
| 2 | 1:50 | 3:40/km | 174 | — |
| 3 | 1:57 | 3:55/km | 175 | 2:00 |
| 4 | 1:57 | 3:55/km | 158 | — |
| 5 | 1:48 | 3:37/km | 173 | — |
| 6 | 2:00 | 4:00/km | 175 | 2:00 |
| 7 | 1:55 | 3:50/km | 156 | — |
| 8 | 1:53 | 3:46/km | 172 | — |
| 9 | 1:57 | 3:53/km | 174 | 2:00 |
| 10 | 1:55 | 3:51/km | 154 | — |
| 11 | 1:48 | 3:36/km | 176 | — |
0.88
confidence
What the engine saw
- 11 work intervals detected from lap markers, confirmed by clear pace separation.
- Recoveries average 120s.
- 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
Recovery41%
Z2
Endurance26%
Z3
Tempo7%
Z4
Threshold15%
Z5
VO₂max10%
Pace
Z1
Easy67%
Z2
Endurance5%
Z3
Tempo19%
Z4
Threshold7%
Z5
VO₂max1%
Z6
Speed0%
Power
Z1
Recovery9%
Z2
Endurance25%
Z3
Tempo31%
Z4
Threshold24%
Z5
VO₂max10%
Z6
Anaerobic2%
Z7
Neuro0%
Aerobic decoupling · Pa:HR-2.9%
Effort & efficiency
0.72
Running effectiveness
speed per watt/kg, reps
6.1 w/kg
Power-to-weight
rep average
2.76
Efficiency factor
norm. power per bpm
1.10
Variability index
1.0 = perfectly even power
3.3%
Rep consistency
pace spread across reps, lower is tighter
1544 kJ
Total work
mechanical energy
845 kcal
Energy
estimated burn
847 bpk
Cardiac cost
heartbeats per km
25%
Above threshold
≥ 164 bpm (Z4+)
-0:48/km
Split balance
negative split, faster 2nd half
Conditions-adjusted pace23°C · +68 m
Actual
3:48/km
Grade-adjusted
3:48/km
Heat-adjusted
3:41/km
−7s/km
True effort
3:41/km
−7s/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.