How fast can I increase my running mileage?

By Mert Yerekapan · Updated

Add no more than about 10 percent to your weekly mileage from one week to the next, and take an easier week every third or fourth week. That is the most common rule, and it's a good one.

The point isn't the exact number. It's that muscles and your cardio fitness adapt quicker than your bones, tendons and joints. If you ramp up faster than the slower tissues can adapt, you feel fine until suddenly you don't.

A worked example

Say you're running 15 miles a week.

  1. Week 1: 15 miles
  2. Week 2: 16.5 miles
  3. Week 3: 18 miles
  4. Week 4: 14 miles, an easier week
  5. Week 5: 19 miles
  6. Week 6: 21 miles

By week 6 you're at 21 miles, up about 40 percent in six weeks. Doing it faster than that tends to catch up with people.

Runs synced from Apple Health are scored in League of Fitness by heart rate zones, so easy runs and lighter weeks still count toward the daily match. That takes away some of the pull to turn every run into a hard one.

Where the rule breaks down

The 10 percent rule is a guideline, not a law.

  • At low mileage, it's too cautious. Going from 6 to 7 miles is nothing.
  • At high mileage, 10 percent is a lot. Going from 40 to 44 miles is a big jump.
  • Beginners may do better counting minutes and adding 5 minutes to one run a week.
  • One long run that is much longer than the rest of your week is a risk by itself. Try to keep your longest run to about a third of weekly mileage.

Signs you're going too fast

  • Pain that lingers into the next day or gets worse as a run goes on
  • Soreness in one spot, especially the shins or feet
  • Heavy legs, trouble sleeping, or a noticeably higher resting heart rate for several days

Cut back for a week or two when you see those. If pain stays beyond a week or is sharp and localized, see a doctor or physical therapist. Shin splints are the classic result of adding too much, too quickly.

After a break

If you took time off, don't jump back to your old mileage. Come back at about half to two thirds of where you were, and build up again.

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