Tempoconfidence 0.75
8km tempo
Colin Dismuke50 km / marathon build
Source: own Strava export
Tempo
8km tempo
Distance
33.1 km
Moving
156:36
Avg HR
163 bpm
Planned vs actual · TrainingPeaksPlanned 2:35:56 · 34.0 kmRan 2:36:36 · 33.1 kmIF 1.28TSS 424
Shape of the sessionEasyWorkFastest
0:00session156:36
The decode
A long run with 8 km and 3 km tempo blocks. It demanded controlled work after prolonged easy running, with a 1 km easy recovery leaving the second block exposed to accumulated fatigue.
The work blocks quickened from 4:12/km to 4:03/km while heart rate moved from 177 to 178. The pace held under fatigue, although the final easy segment slowed to 6:29/km with heart rate at 171.
0.75
confidence
What the engine saw
- A sustained elevated-effort block with controlled pace variation.
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
Recovery3%
Z2
Endurance14%
Z3
Tempo45%
Z4
Threshold13%
Z5
VO₂max24%
Pace
Z1
Easy63%
Z2
Endurance30%
Z3
Tempo7%
Z4
Threshold0%
Z5
VO₂max0%
Z6
Speed0%
Power
Z1
Recovery1%
Z2
Endurance9%
Z3
Tempo74%
Z4
Threshold16%
Z5
VO₂max0%
Z6
Anaerobic0%
Z7
Neuro0%
Aerobic decoupling · Pa:HR+0.2%
Effort & efficiency
0.75
Running effectiveness
speed per watt/kg, reps
4.3 w/kg
Power-to-weight
rep average
2.38
Efficiency factor
norm. power per bpm
1.02
Variability index
1.0 = perfectly even power
74.2%
Rep consistency
pace spread across reps, lower is tighter
4628 kJ
Total work
mechanical energy
2455 kcal
Energy
estimated burn
995 bpk
Cardiac cost
heartbeats per km
38%
Above threshold
≥ 164 bpm (Z4+)
-0:28/km
Split balance
negative split, faster 2nd half
Conditions-adjusted pace25°C · +64 m
Actual
5:11/km
Grade-adjusted
5:11/km
Heat-adjusted
4:59/km
−12s/km
True effort
4:59/km
−12s/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.