Durabilityby Darren Ware
← The training log

Run · Friday, 11 September 2026 · Week 3, Durability Base

Run, 5 miles

29 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 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.

57% at or under 12643% above

Over the cap. Average 126 bpm, with 43% 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
113:15125121 ft
212:4712420 ft
314:48127131 ft
412:5812649 ft
512:2712613 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, Friday, 11 September 2026 | The Coach's Lab | Durability