By Dev K. Mishra, M.D.
President, Sideline Sports Doc
Clinical Assistant Professor of Orthopedic Surgery, Stanford University
• Common advice for runners returning from injury or other layoff is to increase weekly mileage by 10%
• While I find that to be a generally good starting point, some runners are able to increase mileage faster and others must go even more slowly
• From the orthopedic sports medicine standpoint, I often tailor return to running programs based upon the athlete’s unique injury situation
I often see young athletes with lower extremity stress fractures from running. We go through various treatments to allow the injury to heal, including preliminary running on an AlterG antigravity treadmill. After appropriate healing it becomes time to start overland running.
We generally recommend that the athlete follow the 10 percent rule, one of the most widely known in running. It does not specify a starting distance but says you should increase your mileage no more than 10 percent a week. The idea is that this is a safe way to increase your distance without risking re-injury. For example, we may recommend a novice young runner to go a total of 4.5 miles in the first week, and then if still pain free increase by about 10% to 5 miles total in the second week.
The interesting thing I find with this “rule”, like many others, is that athletes will often “cheat”. The higher the level runner, the faster they are likely to increase their mileage. And at the other end of the spectrum some athletes will have a recurrence of discomfort and we need to back off and go even slower.
So where did the “ten percent” rule come from? New York Times columnist Gina Kolata wrote a nice piece on the history of the 10% rule. She writes that there is one good scientific study on the subject. Conducted by researchers at the University of Groningen in the Netherlands.
They investigated the 10 percent rule because it is so popular and seemed to make sense with its gradual increase in effort. The study involved 532 novice runners whose average age was 40 and who wanted to train for a four-mile race held every year in the small town of Groningen.
Half the participants were assigned to a training program that increased their running time by 10 percent a week over 11 weeks, ending at 90 minutes a week. The others had an eight-week program that ended at 95 minutes a week. Everyone warmed up before each run by walking for five minutes. And everyone ran just three days a week.
It turns out they had almost the same injury rates – about 1 in 5 runners.
From a practical standpoint running is actually a fairly complicated thing to do, and then to stick with it. The “ten percent rule” might be more fiction than fact but I still find it a good starting point. The key I think is to then adapt the progression to the particular needs of the young runner.
“Nobody found out if it works or what is the basis of it,” wrote one of the Dutch researchers. And that is the way it often goes in exercise science. People “hear something, they read something,” he said, “and then it’s like a religion.”