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

Distance measurement

Hours

Time in hours

Minutes

Time in minutes

Seconds

Time in 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.