Build Phase 3 | Week 1 | Run 5
Today’s Long Run (Aug 24, 2025) capped off Build Phase 3 | Week 1. The goal: stay aerobic, manage the hills, and lock in marathon fueling practice. While GPS drift affected the Pa:HR number on paper, the actual effort stayed steady and controlled from start to finish.
I had my usual 2 slices white bread and 2 tablespoons of jam roughly 1.5 hours pre-run, then a drink mix 160 finished by about 10 to 15 minutes pre-run. I popped 2 Saltstick Fastchews at that time as well. I stuck to my plan of a Gel 100, 30 minutes into the run, then another 100, followed by a Gel 160 near the end. I washed it down with Nuun.
The hills kept things honest, but I never felt over my head. Legs got heavy at points, but HR stayed steady in the 140s. The GPS trace had its quirks, especially late, which exaggerated my Pa:HR drift. Truth is, I felt smooth and controlled. Fueling sat well the entire way – another confidence builder.
Metrics Summary
| Metric | Value |
| Duration | 2:10:05 |
| Distance | 18.1 km |
| Average Pace | 7:10/km |
| NGP | 6:52/km |
| Calories | 1101 kcal |
| Elevation Gain / Loss | 491 m / 538 m |
| rTSS / hrTSS | 169 / 124 |
| IF (pace) | 0.83 |
| HR (min/avg/max) | 94 / 144 / 154 bpm |
| Pa:HR (reported) | 9.24% |
| Cadence (min/avg/max) | 81 / 163 / 196 spm |
| VAM / VAM W·kg⁻¹ | 226 m/h / 1.15 |
What the Numbers Say
- Reported vs true Pa:HR: The official Pa:HR is 9.24%, which suggests efficiency drift. But lap data tells another story: GPS wobble and partial cool-down laps exaggerated pace without a corresponding HR change. Excluding those, true Pa:HR is closer to ~4–6%, consistent with your aerobic baseline.
- Stress balance: rTSS (169) > hrTSS (124), reflecting the muscular load of climbing (491 m up) rather than cardiovascular breakdown.
- HR control: Avg HR of 144 bpm stayed rock steady in Zone 2, with a modest peak at 154 bpm.
- Cadence: 163 spm average was consistent, showing form stability over hills and distance.
- Fueling: Three gels + Maurten Mix + Nuun + SaltStick all sat perfectly – no GI issues across 2+ hours. A rehearsal win.
Coach’s Corner
- Fueling strategy locked: You’ve now shown you can tolerate your full marathon fueling plan over a substantial effort.
- Don’t chase false Pa:HR: GPS quirks distorted the calculation. The real story is efficiency and stability.
- Training effect: This wasn’t just a long run – it combined elevation, aerobic control, and nutrition rehearsal. That’s marathon specificity at its best.
Conclusion
This Long Run (Aug 24, 2025) delivered exactly what it needed to: duration, climbing, steady HR, and successful fueling. GPS noise aside, the effort was smooth and confidence-building – a strong finish to Week 1 of Build Phase 3.