Run · Friday, 11 September 2026 · Week 3, Durability Base
An unplanned five spends nearly half its time over the cap
29 weeks to MDS
This one wasn't on the plan. I added five miles with 315 feet of climbing, average heart rate landing exactly on the cap, which sounds fine until you look closer: 43 percent of the run sat above it.
Pace picked up a touch by the last full mile, 12:27 against 13:15 at the start, with heart rate barely moving between the two. Nothing here says why, just that the cap was breached often enough to note. I'll see how the next few easy runs sit against it before drawing anything from this one.
- Distance
- 5 mi
- 8.1 km
- Moving time
- 1h 06m
- started 17:20
- Average pace
- 13:12
- per mile
- Heart rate
- 126
- average · max 142
- Climb
- 315 ft
- 96 m
- Conditions
- 18°C
- 64% humidity · wind 10 km/h
An extra run, not on the plan.
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 126 bpm, with 29% 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 | 13:15 | 125 | 121 ft |
| 2 | 12:47 | 124 | 20 ft |
| 3 | 14:48 | 127 | 131 ft |
| 4 | 12:58 | 126 | 49 ft |
| 5 | 12:27 | 126 | 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.