Tempoconfidence 0.75
2km tempo treadmill
Colin Dismuke50 km / marathon build
Source: own Strava export
Tempo
2km tempo treadmill
Distance
13.0 km
Moving
52:56
Avg HR
145 bpm
Planned vs actual · TrainingPeaksPlanned 1:00:00 · 14.0 kmRan 52:56 · 13.0 kmIF 1.36TSS 162
Shape of the sessionEasyWorkFastest
0:00session52:56
The decode
Three 2km threshold reps on a treadmill made this a controlled tempo session with repeated changes of gear. The paired 200m hard efforts demanded quick transitions into sustained work, while the 400m jogs separated the blocks without changing the session's central demand.
The main reps held tightly at 3:30/km, 3:31/km and 3:31/km. Heart rate stayed contained at 148, 149 and 147, so the set finished without a late rise or visible loss of pace.
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
Recovery33%
Z2
Endurance67%
Z3
Tempo0%
Z4
Threshold0%
Z5
VO₂max0%
Pace
Z1
Easy39%
Z2
Endurance11%
Z3
Tempo4%
Z4
Threshold39%
Z5
VO₂max7%
Z6
Speed0%
Power
Z1
Recovery7%
Z2
Endurance17%
Z3
Tempo31%
Z4
Threshold43%
Z5
VO₂max2%
Z6
Anaerobic0%
Z7
Neuro0%
Aerobic decoupling · Pa:HR-3.9%
Effort & efficiency
0.79
Running effectiveness
speed per watt/kg, reps
5.3 w/kg
Power-to-weight
rep average
2.84
Efficiency factor
norm. power per bpm
1.04
Variability index
1.0 = perfectly even power
20.1%
Rep consistency
pace spread across reps, lower is tighter
1289 kJ
Total work
mechanical energy
721 kcal
Energy
estimated burn
621 bpk
Cardiac cost
heartbeats per km
0%
Above threshold
≥ 164 bpm (Z4+)
-0:33/km
Split balance
negative split, faster 2nd half
Conditions-adjusted pace25°C
Actual
4:00/km
Grade-adjusted
4:00/km
Heat-adjusted
3:51/km
−9s/km
True effort
3:51/km
−9s/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.