Tempoconfidence 0.75
15 / 10 / 5 min threshold
Colin Dismuke50 km / marathon build
Source: own Strava export
Tempo
15 / 10 / 5 min threshold
Distance
12.0 km
Moving
49:50
Avg HR
163 bpm
Planned vs actual · TrainingPeaksPlanned 1:09:41 · 16.3 kmRan 49:50 · 12.0 kmIF 1.64TSS 220
Shape of the sessionEasyWorkFastest
0:00session49:50
The decode
A 15/10/5-minute threshold set used descending work blocks separated by easy floats. The shortening blocks kept the effort continuous, requiring control as the work duration fell and the recovery narrowed.
The work accelerated from 3:45/km at 174 HR to 3:44/km at 179 and 3:37/km at 180, so the set held together as the blocks shortened. The recoveries were 5:20/km at 144 HR and 5:11/km at 149 HR; the final easy segment was 5:00/km at 157 HR.
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
Recovery25%
Z2
Endurance9%
Z3
Tempo9%
Z4
Threshold8%
Z5
VO₂max50%
Pace
Z1
Easy39%
Z2
Endurance2%
Z3
Tempo42%
Z4
Threshold18%
Z5
VO₂max0%
Z6
Speed0%
Power
Z1
Recovery0%
Z2
Endurance15%
Z3
Tempo27%
Z4
Threshold39%
Z5
VO₂max16%
Z6
Anaerobic3%
Z7
Neuro0%
Aerobic decoupling · Pa:HR+6.5%
Effort & efficiency
0.72
Running effectiveness
speed per watt/kg, reps
5.2 w/kg
Power-to-weight
rep average
2.72
Efficiency factor
norm. power per bpm
1.03
Variability index
1.0 = perfectly even power
15.7%
Rep consistency
pace spread across reps, lower is tighter
1387 kJ
Total work
mechanical energy
825 kcal
Energy
estimated burn
732 bpk
Cardiac cost
heartbeats per km
58%
Above threshold
≥ 164 bpm (Z4+)
-0:04/km
Split balance
negative split, faster 2nd half
Conditions-adjusted pace28°C · +93 m
Actual
4:24/km
Grade-adjusted
4:24/km
Heat-adjusted
4:11/km
−13s/km
True effort
4:11/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.