I knew it!
I knew that venerable training rule that a runner should increase mileage by no more than 10% per week was bogus. In her Personal Best column, Gina Kolata of the New York Times cites one large study that finds no evidence that the 10% rule makes any difference in injury rates compared to a more rapid increase to a similar peak mileage and to a program that began with four weeks of other kinds of conditioning.
When Running Up Mileage, 10 Percent Isn’t the Cap
While one study can't be considered definitive, the fact that no one seems to know where the 10% rule came from and no one seems to have any evidence for its efficacy in preventing injuries suggests we should take the rule with a whole shaker of salt.
One of the weaknesses of the 10% solution was always that it flew in the face of two common-sense observations: first, it doesn't say anything about your starting point. If you start by running more than you can handle, you'll be in trouble no matter how gradually you increase from there. And second, you can't keep increasing forever or even for very long before you are running higher mileage than you can handle.
For example, if you run 30 miles a week and increase 10% each week, in fourteen weeks you'll be running over 100 miles a week. That can't be right!
Here's another example: I recently had to take several weeks completely off from running. When I started up again, my first seven days I ran about 15 miles. My second week, I ran about 25, a 67% increase, and that was fine for me. "But wait," you say, "that's only because you are a trained runner used to running more miles, and different rules apply..." Fair enough, but doesn't everyone bring some level of training to the game? I mean, if your baseline is 0, then 10% of that is still 0.
The math just doesn't make sense. If your baseline is a mile a day, it will take you 9 weeks to reach 2 miles every day. That's an entire cross-country season to go from one mile a day to two. Ah, but seven weeks after that you'll be running 4 miles a day. Seven weeks after THAT, you'll be running 8 miles a day, and by the end of seven months, you'll be running almost 16 miles per day, or 110 miles a week.
To continue my own example, after that 25 mile week I continued to increase my mileage, and now, fifteen weeks later, I'm running about 45 miles per week. That works out to about a 5% increase per week. Had I followed the 10% rule, I would be running 86 miles per week now, more than I've ever done in my life. So in my case, I used a fairly rapid increase in the first few weeks, followed by a much flatter curve as I approached what I believe is optimal mileage for my age and experience.
As a symbol of progression and gradualism, the 10% rule has some value, I guess. But as the article and the study it cites make clear, it's probably not something you should take too literally.
Subscribe to:
Post Comments (Atom)
1 comment:
Interesting post, Jon. It's funny because as you allude to, the 10% rule is something that every runner - from recreational to elite - learns early on. But of course, the 10% rule is trivial. I never really considered people taking it literally, as to think that they could continue to add 10% to their mileage per week indefinitely as that is a recipe for disaster.
The key to building and increasing mileage is to first set a reasonable goal that you'd like to hit. If you are coming off of an injury or time off, a good rule of thumb is that if you can't build-up to your goal mileage in 4-6 weeks, safely, then it is too much and you need to re-evaluate.
Also, especially in younger runners and older runners, it is very wise to take every third week at 60-70% of that goal mileage. The reason for this is that bone tissue adapts to stress on about 20 day mesocycles. Thus, by adding less load at the end of this cycle, you actually minimize micro-damage at the cellular level, which of course, over time, teaches your body to increase its load capacity. This is where the mileage game becomes very individualized.
If this is all done properly, your body will actually eventually adapt to the point where running more will actually help reduce injuries. The high-high-low week works wonders, but it's key for an athlete to figure out what their mileage threshold is and to work from there.
I'm sure you know this, Jon, but maybe this explanation can help a kid or coach out there trying to figure out the best approach to mileage, especially during the summer months.
Post a Comment