Weekly mileage increase

Plan a gradual build from your current weekly distance to your target.

Your details

From 15.0 miles to 25.0 miles a week

6 weeks

at 10% a week

Week 116.5 miles
Week 218.2 miles
Week 320.0 miles
Week 422.0 miles
Week 524.2 miles
Week 625.0 miles
Biggest rise over any 2 weeks21.0%

A Danish study of new runners (Nielsen 2014) found injuries were more common when weekly distance rose by more than 30% over two weeks. An easier week every third or fourth week is common coaching practice to let the body catch up.

Pain that is sharp, gets worse as you go, or is still there days later is a reason to see a GP or physio.

The working

15 to 25 miles at 10%

16.5, 18.2, 20.0, 22.0, 24.2, then 25: 6 weeks. Over any two weeks the rise is 21%, under the 30% warning level.

With an easier week every 4th week (back 20% to 16 miles), it takes 7 weeks, and the week after the easier one is checked against the last full week, not the easy one. If you ran 11 miles two weeks ago and 15 now, you have already risen 36%, so hold at 15 for a week or two before building.

The evidence

Nielsen 2014

A Danish study of 873 new runners found injuries were more common when weekly distance rose by more than 30% over two weeks. The 10% rule is a simple way to stay well under that.

Build smart

Tips

Every third or fourth week, drop back by a fifth
Add distance to easy runs first
Do not raise speed and distance in the same week
Sleep more when you run more

Read with care

What this cannot tell you

Injury preventionNothing guarantees an injury free build.
Returning runnersAfter a break, start lower than your old distance.
PainPain is a reason to pause the plan.

Questions

Common questions

How much should I increase my mileage?

About 10% a week is a common, safe guide.

Is the 10% rule proven?

Not exactly, but steep jumps of 30% or more over two weeks link to more injuries.

Should I have recovery weeks?

Yes, every 3 or 4 weeks.

Sources

Last checked 21 October 2026. Spotted something wrong? Tell us and we will fix it.

Before you push on

New to exercise, or got a heart, lung or joint condition? Have a word with your GP or practice nurse first. Stop and get help if you feel chest pain, faintness or unusual breathlessness, and call 999 if it is severe.