Durabilityby Darren Ware
← The training log

Run · Tuesday, 25 August 2026 · Week 1, Durability Base

Run, 5 miles

31 weeks to MDS

My write-up for this run isn't up yet. Everything the watch recorded is below.

Distance
5 mi
8.1 km
Moving time
1h 03m
started 11:21
Average pace
12:37
per mile
Heart rate
128
average · max 146
Climb
312 ft
95 m
Conditions
–
52% humidity

The planned easy run, a different distance from 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.

41% at or under 12659% above

Over the cap. Average 128 bpm, with 59% 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

MilePaceAvg HRClimb
112:43126121 ft
211:5512820 ft
313:45130115 ft
412:2912846 ft
512:1912813 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.

Run, Tuesday, 25 August 2026 | The Coach's Lab | Durability