The 10% Rule: This is a simple and time tested rule that gives guidance on increasing weekly running mileage and returning to run after injury.

Lets break down this rule with a little more depth and context below:

Starting To Run For The First Time?

This is the bread and butter of the 10% rule and what the rule was originally intended for.

Research and experience has shown that those who increase their running mileage by no more than 10% a week are less likely to have a running related injury.

Sounds good, right?

The 10% rule gives us great guidance on how to advanced our training, but where would someone new to running even start?

General fitness levels and athletic background can all factor into a starting point. But, if we are speaking in generalities a smart starting point would be one that is very modest. An example of this might be running 1 mile 2-3 times per week and increasing each week using the 10% rule.

That means if you ran 1 mile 3 times a week during week 1, you would run 1.1 miles 3 times a week the second week. On the third week you would then run 1.2 miles 3 times a week.

When you do the math the 10% rule is a slow, sometimes painful slow, progression.

That however is the point, this allows for your body enough time to adapt to the new demands that are placed on it.

Eventually those small 10% increases over time could up add to be significant distances.

Recovering From An Injury?

The 10% rule is traditionally taught as a means to gradually increase running mileage, but this rule can be easily applied to those returning to run after an injury.

Again the 10% rule allows for the body to gradually adapt over time to the load that is being placed on it.

So we now have a safe progression, but what mileage would a runner start from after recovering from an injury?

The answer will be different for each person.

If you haven’t taken any time off from running then the answer would most likely be the greatest mileage you can run without symptoms. This means that you would be starting at mileage that your body is capable of handling.

From that point the goal would be to follow the 10% rule.

But what if you have taken time off from running?

Again, this answer becomes more complicated. One month off would be a lot different than a year off from running.

As an example: Lets say we have two identical runners (Runner A and Runner B) with the same history of marathon running and the same aspirations of running another marathon in the future.

If Runner A took one month off and Runner B took one year off, their individual starting points at a return to run program would be very different. Runner A’s starting point would be much closer to where they left off, maybe somewhere in the 70% range of the mileage they left off at. Runner B’s starting point would likely be less than 50% of the mileage they left off at a year ago.

Expanding On the 10% Rule:

The 10% rule, as we all know now, is generally taught for running mileage. However we can also expand this rule and use it for running pace as well as other sports.

Progressing ones tempo training or their speed workout should also follow this same rule. Obviously the 10% rule will only work up to a point, eventually one’s abilities will make it difficult from continuing to improve at a 10% rate, but if you are looking to pick up the pace of your temp run, a 10% increase may be the limit of what you consider as a weekly progression.

Running is one of the easiest activities to quantify as it is a relatively predictable sport. Other sports, particularly team sports like lacrosse, football, basketball, soccer, etc. are more difficult to quantify in terms of effort, as the play is less predictable.

That doesn’t mean however that one can’t use the tried and true 10% rule more subjectively when returning to a team sport. Though it may be hard to directly quantify, the rule can provide an athlete with general guidance on how to return to their sport, rather than just winging it or rushing back in.

In Conclusion

Understanding and using the 10% rule can be one of the best things you do as a runner or athlete returning from an injury.

With any activity you need to give your body time to adapt safely and the 10% rule does a good job at that.