Intervalsconfidence 0.83
10 × 400m
Colin Dismuke50 km / marathon build
Source: own Strava export
Intervals
10 × 400m
Distance
12.2 km
Moving
54:38
Rep pace
3:25/km
Avg HR
153 bpm
Reps
10
Planned vs actual · TrainingPeaksPlanned 53:04 · 12.0 kmRan 54:38 · 12.2 kmIF 1.47TSS 195
Shape of the sessionEasyWorkFastest
warm up
cool down
0:0010 × work / float54:38
The decode
This was a continuous interval set of 10 × 400m with 200m float recoveries. The structure kept the work and recovery running as one sequence.
The reps moved from 1:18 at 3:15/km to 1:25 at 3:33/km, with the slower running concentrated in the second half. Rep heart rate rose from 145 on the first to 174 on the ninth before dropping to 166 on the final rep.
Rep splits
| Rep | Time | Pace | HR | Float |
|---|---|---|---|---|
| 1 | 1:18 | 3:15/km | 145 | 0:57 |
| 2 | 1:21 | 3:22/km | 152 | 1:04 |
| 3 | 1:20 | 3:19/km | 156 | 1:05 |
| 4 | 1:21 | 3:21/km | 163 | 1:06 |
| 5 | 1:23 | 3:29/km | 161 | 1:07 |
| 6 | 1:21 | 3:23/km | 173 | 1:05 |
| 7 | 1:24 | 3:29/km | 171 | 1:03 |
| 8 | 1:22 | 3:26/km | 173 | 1:07 |
| 9 | 1:24 | 3:30/km | 174 | 1:05 |
| 10 | 1:25 | 3:33/km | 166 | 0:60 |
0.83
confidence
What the engine saw
- 10 work intervals detected from lap markers, confirmed by clear pace separation.
- Recoveries average 64s.
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
Recovery31%
Z2
Endurance25%
Z3
Tempo22%
Z4
Threshold11%
Z5
VO₂max10%
Pace
Z1
Easy72%
Z2
Endurance8%
Z3
Tempo2%
Z4
Threshold9%
Z5
VO₂max8%
Z6
Speed0%
Power
Z1
Recovery0%
Z2
Endurance23%
Z3
Tempo52%
Z4
Threshold18%
Z5
VO₂max7%
Z6
Anaerobic1%
Z7
Neuro0%
Aerobic decoupling · Pa:HR+11.7%
Effort & efficiency
0.82
Running effectiveness
speed per watt/kg, reps
5.9 w/kg
Power-to-weight
rep average
2.69
Efficiency factor
norm. power per bpm
1.04
Variability index
1.0 = perfectly even power
2.6%
Rep consistency
pace spread across reps, lower is tighter
1667 kJ
Total work
mechanical energy
841 kcal
Energy
estimated burn
882 bpk
Cardiac cost
heartbeats per km
22%
Above threshold
≥ 164 bpm (Z4+)
+0:01/km
Split balance
positive split, slower 2nd half
Conditions-adjusted pace31°C · +53 m
Actual
3:25/km
Grade-adjusted
3:25/km
Heat-adjusted
3:12/km
−13s/km
True effort
3:12/km
−13s/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.