Run · Thursday, 1 October 2026 · Week 6, Durability Base
A new, higher cap gets tested on an easy run
26 weeks to MDS
My heart rate cap moved up to 131 this week, and this run was the first real look at it. Five miles done, a touch short of the easy run the plan called for.
The average sat a point under the new cap, but more than a third of the time out there ran above it. Pace picked up from 13:15 to 12:29 over the run, with heart rate drifting from 126 to 131 across that same stretch, so the effort climbed as the pace did.
As I noted afterwards, I'd like to see this settle closer to 128 or 129 rather than sitting at the ceiling. The next few easy runs will tell me whether that's realistic at this pace, or whether the pace needs to come down to get there.
From my training journal
“My HR cap has increased to 131. Good to see if I can keep here or need to come down to 128/129”
Easy effort · Good rhythm
- Distance
- 5 mi
- 8.1 km
- Moving time
- 1h 06m
- started 18:59
- Average pace
- 13:10
- per mile
- Heart rate
- 130
- average · max 151
- Climb
- 318 ft
- 97 m
- Conditions
- 15°C
- 61% humidity · wind 10 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 130 bpm, with 22% 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 | 13:15 | 126 | 115 ft |
| 2 | 12:32 | 129 | 20 ft |
| 3 | 14:22 | 133 | 128 ft |
| 4 | 13:21 | 129 | 46 ft |
| 5 | 12:29 | 131 | 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.