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Ignore the 10 Percent “Rule”

You’ve probably heard that, when upping your running volume, you shouldn’t increase your mileage by more than 10 percent a week. You have not only my permission but my encouragement to ignore this “rule.”

For starters, as I’ve mentioned, the unit of a mile has no meaning to the human body. Neither does the seven-day cycle we call a week. Neither does the base-10 number system, our use of which is where the “rule” comes from. (Did the Babylonian coaches of antiquity dole out advice about increasing volume in units of 60 because they happened to grow up using a base-60 number system?) So it stands to reason that combining these three variables doesn’t make for any sort of sound guidance.

Alison Wade

Even if the intent of the “rule” is more right than wrong—i.e., increase your running volume gradually to allow your body to adapt—its literal application can have comical consequences. Say someone is running 4 miles a day, 3 days a week. He decides he wants to run more than 12 miles per week. He’s in good health, has no injury problems, and simply wants to run more to feel that much better and get fitter. Applying the 10 percent formula, he would move to 13.2 miles per week, then 14.5, then 15.9, and finally 17.4 by the end of the month. For most people, this is like locking your house every time you go next door to borrow an egg—safe, certainly, but verging into letting fear of something bad happening overwhelm everything else.