Tempoconfidence 0.75
2.4km tempo
Colin Dismuke50 km / marathon build
Source: own Strava export
Tempo
2.4km tempo
Distance
15.7 km
Moving
70:54
Avg HR
159 bpm
Planned vs actual · TrainingPeaksPlanned 1:15:44 · 16.0 kmRan 1:10:54 · 15.7 kmIF 1.30TSS 200
Shape of the sessionEasyWorkFastest
0:00session70:54
The decode
A 15'+10'+5' tempo set concentrated the work into three sustained blocks. The short easy resets left the final block under accumulated load, making the close sharper than the opening work.
The work progressed from 4:28/km at HR 160 to 4:09/km at HR 169 and 3:53/km at HR 175. The pace quickened as the heart-rate response rose, with the sequence holding together through the finish.
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
Recovery9%
Z2
Endurance22%
Z3
Tempo25%
Z4
Threshold39%
Z5
VO₂max5%
Pace
Z1
Easy33%
Z2
Endurance58%
Z3
Tempo9%
Z4
Threshold1%
Z5
VO₂max0%
Z6
Speed0%
Power
Z1
Recovery1%
Z2
Endurance5%
Z3
Tempo71%
Z4
Threshold20%
Z5
VO₂max3%
Z6
Anaerobic0%
Z7
Neuro0%
Aerobic decoupling · Pa:HR+2.8%
Effort & efficiency
0.72
Running effectiveness
speed per watt/kg, reps
5.2 w/kg
Power-to-weight
rep average
2.50
Efficiency factor
norm. power per bpm
1.02
Variability index
1.0 = perfectly even power
7.7%
Rep consistency
pace spread across reps, lower is tighter
1748 kJ
Total work
mechanical energy
1110 kcal
Energy
estimated burn
757 bpk
Cardiac cost
heartbeats per km
44%
Above threshold
≥ 164 bpm (Z4+)
-0:19/km
Split balance
negative split, faster 2nd half
Conditions-adjusted pace33°C · +56 m
Actual
4:29/km
Grade-adjusted
4:29/km
Heat-adjusted
4:11/km
−18s/km
True effort
4:11/km
−18s/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.