How many weeks do I need to train for a marathon?

Most plans are 12-20 weeks. Beginners should allow 16-20 weeks with a solid base of 25-30 km per week before starting. Experienced runners can use 12-16 week plans. The key is having enough time to build mileage gradually without injury.

What is the 10% rule?

The 10% rule suggests increasing weekly mileage by no more than 10% per week to reduce injury risk. While not a hard scientific rule, it provides a sensible guideline. Some runners can handle faster increases, others need more conservative build-up.

How important is the long run?

The long run is the cornerstone of distance training. It builds aerobic endurance, teaches your body to burn fat, and builds mental toughness. Typically 25-35% of weekly mileage, run at easy pace (60-90 seconds slower than race pace).

The taper is a planned reduction in training volume before race day, allowing your body to recover and perform at its best. Typically 1-3 weeks depending on race distance. Maintain intensity but reduce volume by 20-40% each taper week.

RunCalcs

Training Plan Builder

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Goal Race

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Current Weekly Mileage

Your age in years

Weeks Until Race

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Experience Level

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How We Calculate This

Mileage Progression

Weekly mileage builds gradually from current level to a peak, with step-back weeks every 3rd week for recovery. The peak mileage is determined by race distance and experience level.

Taper Schedule

Volume reduces by approximately 20% each taper week. Marathon: 3-week taper. Half marathon: 2 weeks. Shorter races: 1 week.

Frequently Asked Questions

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Tempo Pace Calculator

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Last updated: 2026-03-01

All calculations are estimates. Always consult a coach or medical professional for personalised training advice.