Intervalsconfidence 0.83
5 × 800m
Colin Dismuke50 km / marathon build
Source: own Strava export
Intervals
5 × 800m
Distance
12.2 km
Moving
56:05
Rep pace
3:33/km
Avg HR
160 bpm
Reps
9
Planned vs actual · TrainingPeaksPlanned 53:05 · 12.2 kmRan 56:05 · 12.2 kmIF 1.32TSS 162
Shape of the sessionEasyWorkFastest
warm up
cool down
0:009 × work / float56:05
The decode
It was a progression interval session built around a 2km build, a recovery, and five 800m repetitions. The stated intent was progression from the previous week.
The 800m repetitions ran at 3:23/km, 3:31/km, 3:40/km, 3:36/km and 3:41/km. Heart rate ranged from 170 to 176 across the set, with the pace fading after the opening repetition and a brief lift on the fourth.
Rep splits
| Rep | Time | Pace | HR | Float |
|---|---|---|---|---|
| 1 | 1:46 | 3:32/km | 163 | — |
| 2 | 1:43 | 3:26/km | 172 | — |
| 3 | 1:44 | 3:29/km | 176 | — |
| 4 | 1:51 | 3:42/km | 180 | 2:34 |
| 5 | 2:43 | 3:23/km | 175 | 0:54 |
| 6 | 2:49 | 3:31/km | 176 | 1:24 |
| 7 | 2:56 | 3:40/km | 170 | 1:13 |
| 8 | 2:53 | 3:36/km | 174 | 1:29 |
| 9 | 2:57 | 3:41/km | 170 | 1:11 |
0.83
confidence
What the engine saw
- 9 work intervals detected from lap markers, confirmed by clear pace separation.
- Recoveries average 88s.
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
Endurance20%
Z3
Tempo26%
Z4
Threshold13%
Z5
VO₂max25%
Pace
Z1
Easy62%
Z2
Endurance2%
Z3
Tempo15%
Z4
Threshold13%
Z5
VO₂max7%
Z6
Speed1%
Power
Z1
Recovery8%
Z2
Endurance35%
Z3
Tempo22%
Z4
Threshold25%
Z5
VO₂max10%
Z6
Anaerobic0%
Z7
Neuro0%
Aerobic decoupling · Pa:HR+11.9%
Effort & efficiency
0.77
Running effectiveness
speed per watt/kg, reps
6.1 w/kg
Power-to-weight
rep average
2.53
Efficiency factor
norm. power per bpm
1.08
Variability index
1.0 = perfectly even power
3.0%
Rep consistency
pace spread across reps, lower is tighter
1325 kJ
Total work
mechanical energy
879 kcal
Energy
estimated burn
772 bpk
Cardiac cost
heartbeats per km
38%
Above threshold
≥ 164 bpm (Z4+)
+0:28/km
Split balance
positive split, slower 2nd half
Conditions-adjusted pace37°C · +36 m
Actual
3:33/km
Grade-adjusted
3:33/km
Heat-adjusted
3:16/km
−17s/km
True effort
3:16/km
−17s/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.