The Grantham Triangle

Aug 13, 2025

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Intro: Lee Grantham’s “Are You Making This HUGE Long Run Mistake?” covers some useful training principles. Here’s what stands out.

Key points:

Long runs should feel controlled. You’re holding back. That restraint signals you’re in the right zone (zone 1-2).
The “triangle” framework: endurance from long runs, aerobic capacity from 70-minute threshold sessions, and speed from speed work.
Track effort and heart rate (around 130 bpm at 5:30 min/km) rather than chasing pace. As fitness improves, the same effort gets faster.
Build long-run paces gradually (5:30, 5:20, 5:15), and add 20-minute blocks at 5K race pace (around 4:00 min/km) that sharpen over time.

Workout:

Base long run: 90 minutes at 5:30 min/km (zone 1-2, around 130 bpm).
Threshold run: 70 minutes at 5:00 min/km (zone 2-3).
Speed work: 20 minutes of hard efforts at 5K pace (around 4:00 min/km) with recoveries, building toward 3:55-3:50 min/km.

Closing note: run these and adjust paces in the Pacing app to your effort level.

References