Run · Saturday, 26 September 2026 · Week 5, Durability Base
An easy run runs hot under humid skies
26 weeks to MDS
Five miles, the easy run on the plan for week five, though not quite the length called for. Humidity was the only weather worth noting, with 315 feet of climbing on the way.
Average heart rate came in two over the cap, and 61 percent of the time was spent above it, a much bigger share than the average alone suggests. Pace barely moved, 12:41 for the first mile and 12:35 for the last, so none of that effort showed up on the surface.
One run like this doesn't tell me much on its own. I'll want to see whether this gap between pace and time above cap keeps showing up in the easy runs ahead.
- Distance
- 5 mi
- 8.1 km
- Moving time
- 1h 04m
- started 10:59
- Average pace
- 12:46
- per mile
- Heart rate
- 128
- average · max 149
- Climb
- 315 ft
- 96 m
- Conditions
- 15°C
- 75% humidity · wind 13 km/h
Planned easy run, full distance.
Heart rate against my cap
My easy running has a heart rate ceiling of 126 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 128 bpm, with 47% of the run above 126. 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 | 12:41 | 124 | 121 ft |
| 2 | 12:22 | 128 | 20 ft |
| 3 | 13:49 | 131 | 121 ft |
| 4 | 12:36 | 131 | 46 ft |
| 5 | 12:35 | 127 | 13 ft |
Heart rate in orange is above the 126 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.