The 10-percent rule in running: how to start?

Question

I'm 47 and I never ran for exercise in my life. I live next to an outdoor running track, so like everybody else during the pandemic I decided to start running: the very first day I ran just 1 lap (450 meters, as an amateur I know we have to be at the outer lanes). The second day I was able to run 2 laps, but given my age I thought that I should increase just 1 lap per day, to avoid any cardiac surprise. Thus I ran 3 laps the following day, then 4, and so on. A few days later I was very excited after running 5km (12 laps, pace of 6:33min/km). I thought I was being prudent by increasing just 1 lap per day, looking after my heart... little did I know that I completely blew the 10-percent rule ("never increase your weekly mileage by more than 10 percent over the previous week").

I had a knee injury so bad that I was almost unable to walk for a couple of days. After 40 days my knees are 100% fine now, and during that recovery I read a lot about running (the 10-percent rule, stretching, running form etc...). Now I want to start running again, and I do understand the importance of the 10-percent rule.

But, as a beginner, my question is "10 percent of what"? What should be my initial milleage? Obviously "just run until you feel you need a walking break" won't work because now I know that I'm able to run a dozen laps without walking breaks (but destroying my knees in the process).

Answer 1

As you've discovered, the 10% rule isn't really applicable to someone who is completely new to running. It requires that you already have an established weekly running volume that you can tolerate, so it's really only for already established runners.

As a beginner, you'd be better off starting with a dedicated beginner program, such as Couch to 5k, which can take you from having never run before to a point where you can either begin a different, intermediate-targeted program, or just start using the 10% rule.

Answer 2

The answer from David Scarlett is a very good point that the 10% rule doesn't really work if you are starting at 1 mile a week or something similar. A couch to 5k plan is a good start, but one of the other important factors, after you have completed that plan, is to increase volume while also preventing injury. Sometimes heart and legs will tell you they want to run faster and longer on a day, but your joints and stabilizing muscles may not be ready yet, so make small changes. You might feel good for two days after running longer and faster but there is a good chance that two weeks later you have an odd injury in your feet or groin or elsewhere. (and don't forget to stretch, sleep, and drink water!)