Sub-3 is the marathon's iconic threshold. It demands ~4:15/km for 42 km — and a structured 18-week build with VO₂ max, threshold and marathon-pace work.
Are you ready?
Sub-3 requires roughly a sub-1:25 half-marathon as a prerequisite. If your half is slower, build half-marathon speed first — chasing sub-3 from a 1:30 base usually ends in late-race collapse.
Mileage target during peak weeks is 90–110 km. If your base is lower, give yourself a six-month runway, not 18 weeks.
Weekly structure
Seven days, three quality sessions, four easy runs.
- Tuesday — Threshold (e.g. 5×2 km @ 4:00/km, 90″ rest).
- Thursday — VO₂ or hills (e.g. 8×800 m @ 3:45/km).
- Sunday — Long run with MP segments (e.g. 30 km with 3×5 km @ 4:15).
- Other days — easy 6/10 effort, 5:00–5:30/km.
Race execution
Even pacing wins. Plan 4:14/km for the first 30 km and 4:12 for the last 12 km if you have it.
Take a gel every 25 minutes from minute 30. Caffeinate the last two gels.
Choose a flat, cool, well-organised course. Sub-3 attempts in heat or hilly courses cost 2–4 minutes.
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