Intervalsconfidence 0.83
5 × 2km
Colin Dismuke50 km / marathon build
Source: own Strava export
Intervals
5 × 2km
Distance
16.3 km
Moving
70:18
Rep pace
3:54/km
Avg HR
159 bpm
Reps
5
Planned vs actual · TrainingPeaksPlanned 1:03:12 · 15.0 kmRan 1:10:18 · 16.3 kmIF 1.53TSS 274
Shape of the sessionEasyWorkFastest
warm up
cool down
0:005 × work / float70:18
The decode
The session was a five-by-2km set below threshold at goal marathon pace, adjusted for sun and headwind. The two-minute recoveries separated each rep.
The reps ran at 3:55/km, 3:56/km, 3:54/km, 3:55/km and 3:52/km, with the cut-down arriving on the final repetition. Heart rate rose from 139 to 179 across the set.
Rep splits
| Rep | Time | Pace | HR | Float |
|---|---|---|---|---|
| 1 | 7:50 | 3:55/km | 139 | 2:00 |
| 2 | 7:53 | 3:56/km | 174 | 2:00 |
| 3 | 7:47 | 3:54/km | 175 | 2:00 |
| 4 | 7:50 | 3:55/km | 177 | 2:00 |
| 5 | 7:45 | 3:52/km | 179 | 2:00 |
0.83
confidence
What the engine saw
- 5 work intervals detected from lap markers, confirmed by clear pace separation.
- Rep paces descend across the set (a cut-down / progression).
- Recoveries average 120s.
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
Endurance4%
Z3
Tempo11%
Z4
Threshold13%
Z5
VO₂max39%
Pace
Z1
Easy44%
Z2
Endurance7%
Z3
Tempo50%
Z4
Threshold0%
Z5
VO₂max0%
Z6
Speed0%
Power
Z1
Recovery1%
Z2
Endurance12%
Z3
Tempo43%
Z4
Threshold41%
Z5
VO₂max3%
Z6
Anaerobic0%
Z7
Neuro0%
Aerobic decoupling · Pa:HR+13.1%
Effort & efficiency
0.73
Running effectiveness
speed per watt/kg, reps
5.8 w/kg
Power-to-weight
rep average
2.61
Efficiency factor
norm. power per bpm
1.02
Variability index
1.0 = perfectly even power
0.6%
Rep consistency
pace spread across reps, lower is tighter
1808 kJ
Total work
mechanical energy
1118 kcal
Energy
estimated burn
720 bpk
Cardiac cost
heartbeats per km
52%
Above threshold
≥ 164 bpm (Z4+)
-0:14/km
Split balance
negative split, faster 2nd half
Conditions-adjusted pace31°C · +20 m
Actual
3:55/km
Grade-adjusted
3:55/km
Heat-adjusted
3:40/km
−15s/km
True effort
3:40/km
−15s/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.