The plan was a long slow distance (LSD) run in peak summer humidity. 28°C when stepping out at 8:28 AM, reaching 30°C by the finish, with humidity holding at 83%.
In these conditions, the hardest part isn’t the distance — it’s managing the ego to keep heart rate from drifting into high zones.
90% Zone 2: Discipline Under Heat#
Holding heart rate under heat is an exercise in pacing discipline.
Today’s session finished with 90% in Zone 2 and only 10% in Zone 3. Looking at the zone distribution bar on the share card, the yellow Zone 3 segment aligns almost entirely with the elevation gains (88m climb in total). Whenever the road pitched upward, heat and gravity combined to push heart rate up briefly.
On the flats, active slowing down kept the average heart rate at 137 bpm (Max 149 bpm).
Rather than chasing a faster pace, dialing back allowed the aerobic system to work efficiently without building cumulative fatigue.
Form and Cadence: Zero Collapse#
The second victory today was how the body felt in the final kilometres.
- Cadence: Held at 184 spm throughout the 1:57:56 duration.
- Form: Stride length stayed compact (0.84m) and rhythm remained smooth, preventing the slouch and stride collapse that often happens late in humid long runs.
- Power Output: Averaged 140W with 76% intensity.
Finishing 17.91km in 30°C heat with strong posture and zero feeling of breakdown is the best validation that the load was calibrated correctly.
The Moment of the Day#
At one point along the route, a little squirrel stopped right by the trail. We stared at each other for a few seconds. By the time I pulled out my phone to take a photo, it darted into the trees.
Some moments stay uncaptured on camera, but they make the long miles memorable.
Previous log: July 26 Recovery Run — 12.43km with EF jump to 1.18.