Run · Wednesday, 19 August 2026
Run, 6 miles
32 weeks to MDS
My write-up for this run isn't up yet. Everything the watch recorded is below.
- Distance
- 6 mi
- 9.7 km
- Moving time
- 1h 18m
- started 18:19
- Average pace
- 12:59
- per mile
- Heart rate
- 123
- average · max 151
- Climb
- 423 ft
- 129 m
- Conditions
- –
- 68% humidity
How well the running held up
I compare how efficiently I was running early in the run (speed for each heartbeat, corrected for hills) with the late part. The drop was 2.4%. Under 5% is what I call held. That band is a coaching convention, not a validated threshold.
Late on, pace slowed 10.5% and heart rate fell 8.3%.
Confidence: medium (the late section was mostly descending; the hill correction changed this reading by about 18 points, and it is an estimate).
First half against second half
Comparing pace against heart rate in the first half with the second, the gap was -3.3%. Under 5% is the convention I coach to: it suggests the aerobic side coped with the length of the run. It says nothing about why.
Mile by mile
| Mile | Pace | Avg HR | Climb |
|---|---|---|---|
| 1 | 12:09 | 123 | 95 ft |
| 2 | 13:17 | 130 | 128 ft |
| 3 | 13:02 | 125 | 39 ft |
| 4 | 12:45 | 123 | 66 ft |
| 5 | 14:06 | 121 | 98 ft |
| 6 | 12:14 | 116 | 0 ft |
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.