Run · Tuesday, 29 September 2026 · Week 6, Durability Base
A tidy average masks real time over cap
26 weeks to MDS
The average heart rate landed two under the cap, which reads as clean on paper. But a third of this run was spent above it, something the average alone would never show.
Five miles on Tuesday 29 September, the easy run for week six, though not quite the session as planned. Humid air was the only weather worth mentioning. Pace sat close between first mile and last, and it felt like good rhythm throughout.
One run like this doesn't change anything on its own. I'll be watching whether a low average hiding this much time over cap turns up again on the next easy days.
From my training journal
Good rhythm
- Distance
- 5 mi
- 8.1 km
- Moving time
- 1h 04m
- started 07:33
- Average pace
- 12:46
- per mile
- Heart rate
- 129
- average · max 146
- Climb
- 315 ft
- 96 m
- Conditions
- 14°C
- 94% humidity · wind 15 km/h
Planned easy run, distance changed on the day.
Heart rate against my cap
My easy running has a heart rate ceiling of 131 bpm. It keeps the effort aerobic while my legs, tendons and joints catch up with the mileage. A run counts as over the cap when the average is more than 2 beats over it, or more than a fifth of the time sits above it.
Over the cap. Average 129 bpm, with 21% of the run above 131. The fix is to slow down, walk the steeper bits if I need to, and let it settle.
Mile by mile
| Mile | Pace | Avg HR | Climb |
|---|---|---|---|
| 1 | 13:10 | 126 | 115 ft |
| 2 | 12:13 | 128 | 20 ft |
| 3 | 13:41 | 131 | 118 ft |
| 4 | 12:32 | 132 | 52 ft |
| 5 | 12:19 | 130 | 13 ft |
Heart rate in orange is above the 131 bpm cap.
Figures from my watch via Intervals.icu, read by the Ultra Event Training app. Heart rate from a watch is a proxy for effort, not a lab measure. The efficiency figures compare speed per heartbeat early and late in a run with a hill correction; they show what changed, not the cause.