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How to pace a marathon

Effort-first marathon pacing rules: how to start, when to settle, how to handle hills/heat, and how to avoid the classic late-race crash.

Last updated/Feb 03, 2026, 02:17 PM

The pacing goal

A good marathon is not a perfect first 10K — it’s a controlled first 30K.

The 3-rule pacing system

  1. Start conservative. If it feels “too easy” early, you’re doing it right.
  2. Settle into rhythm. From 10K to 30K, you’re protecting your legs and your fueling.
  3. Race the last 10K. Only spend matches when you know you can pay for them.

Hills + heat (don’t chase splits)

  • Uphill: pace by effort
  • Downhill: run smooth; don’t smash your quads
  • Heat: slow the target pace and fuel/hydrate early

Checklist

Do this, not that

Race-day pacing checklist

  • • I will start 10–20 sec/km slower than goal pace for the first 3–5 km.
  • • I will not surge to ‘get time back’ early.
  • • I will follow a fueling schedule from the first 30 minutes.
  • • I will treat hills as effort-based segments, not split-based segments.
  • • If I feel amazing at 30K, I will only then consider pushing.
  • • My plan for cramps/GI distress is: ____
  • • My plan B goal (finish strong) is clear if conditions are bad.
  • • I will take the first 5 minutes of aid stations calmly (no panic).

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FAQs

Should I aim for an even split?

Even splits are fine, but many runners do best with a gentle negative split. Start controlled so you can finish strong.

How much should I adjust for heat?

More than you think. Slow your target pace, fuel earlier, and treat the day as an execution race rather than a PR chase.

What’s the biggest pacing mistake?

Surging early because it feels easy. The bill comes due late.

Keep going

Running Pace Calculator (with Splits)

Convert distance + time into pace per km/mile and generate a splits table. Useful for planning workouts and race pacing.

Marathon Fueling Planner (Carbs Schedule)

Turn a carbs-per-hour target into a simple fueling schedule you can practice in training and execute on race day.

18-Week Marathon Training Plan

A 18-week marathon training plan with week-by-week structure, workouts, adaptation rules, and built-in pace + fueling tools. Variations are included on one page.

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