How fast should long runs be?

Long runs should be 60-90 seconds per km slower than your 5K pace, or 20-35% slower than race pace. You should be able to hold a conversation throughout.

How long should a long run be?

For marathon training, long runs typically peak at 32-35 km (20-22 miles), 2-3 weeks before race day. For half marathon training, long runs peak at 18-21 km.

Should I include faster sections in long runs?

Advanced runners sometimes include a marathon-pace segment in the final third. For most runners, keeping the entire long run at easy pace is more effective and safer.

RunCalcs

Long Run Pace Calculator — Endurance Building Pace

Calculate your ideal long run pace range for building endurance.

Race Distance

Hours

Minutes

Seconds

How We Calculate This

Long Run Pace

Long Run Pace = 120-135% of race pace

This pace builds aerobic endurance, teaches your body to burn fat efficiently, and prepares your legs for the impact of longer distances.

Frequently Asked Questions

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Last updated: February 2026

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