Forget the 10% Rule: How to Increase Mileage Safely

Is the 10% Rule bogus? Not really, but it certainly doesn’t show you how to increase mileage in every situation.

How to Increase Mileage

I read about running constantly.  Learning about the sport is something I’m passionate about.  But no matter where I am – Runner’s World, Running Times, – I keep seeing so-called “experts” recommend the 10% Rule.

The 10% Rule simply states that you should only increase mileage in increments of 10%.  So if you are running 20 miles this week and want to increase mileage, you should only run 2 more miles in order to stay “safe.”

I have so many problems with the 10% Rule.

This apparently golden rule of running is extremely general and doesn’t apply to many training situations.  Are you being too conservative with your mileage?  Maybe you’re even being too aggressive.  If you’re adding miles to your program, you also have to ensure you’re doing the right strength workouts to prevent injury.

Let’s deconstruct the 10% Rule and figure out how to increase  mileage safely.

How to Increase Mileage

The 10% Rule must be modified depending on who you are and how much you’re running. Use this framework to better understand how to run more miles safely with as little injury risk as possible.

Beginners: Forget the 10% Rule

If you’re a beginner, forget the 10% Rule entirely.  As a beginning runner, your main priority is to run consistently and allow your body to get used to running.  This probably means running 2-3 days per week for 1-4 miles.  As a newbie, don’t increase your mileage every week.  Keep it the same for 3-4 weeks at a time to allow your body to adjust.  When you’re comfortable, then you can add mileage.

Make sure you have a few pairs of running shoes that you can alternate to make increasing mileage easier on your legs. If you’re very sore, a massage can help ease the tightness in your legs or you could also use a foam roller.

Running more miles as a new runner means looking at how many days you run per week, your longest run, and your typical run per day.  If you run 3 days per week – 2 miles, 3 miles, and 3 miles – and ready for more mileage, you can start running four days per week.

Simply add another day of 2 miles to your schedule.  You might argue that’s 25% of your previous volume, but this is entirely safe provided you were comfortable with your previous volume. Stick with your new running schedule of 10 miles for another 3 weeks or so, then consider an additional jump.

You can also decrease one run by a mile and increase another to give yourself a long run.  Now your schedule might be 2, 2, 4, 2 miles.  The possibilities are endless.

Experienced Runners: Adapt the 10% Rule

As a more experienced runner, adapt the 10% Rule to fit your schedule. Sometimes adding 10% of your mileage works – like going from 50 to 55 miles after becoming very comfortable with that volume.  But if you are adding another day of running, your mileage may increase by 15 or 20%.

Advanced runners will find that they have a mileage sweet spot.  This particular volume will be comfortable for you but moving past it will be a challenge.  You may find yourself increasingly tired, prone to injury, or running poorly in workouts.

For me, running 60 miles per week is easy.  I can get in pretty good shape doing this type of volume.  I can also jump very significantly up to 60 miles per week after a break in training.

If I want to race at my peak however, I have to run more.  This is where I run into problems.  I’ve always found it difficult to run more than 70 miles per week.  My injury potential skyrockets so at this level I take it very easy.  I increase my miles only 5-10% and hold it at that level for several weeks.  Consistency and long-term development is more important than jumps in mileage.

Haven’t Run Recently? Forget the 10% Rule

When you’re coming back from a brief break in training, don’t even think about the 10% Rule. If you’re an intermediate runner who was comfortable running 35 miles per week for two months, you are not starting from scratch after a 1-2 week break.  You can easily begin your mileage at 20-25 and go back to 35 after a few weeks.

At this point, it’s more important to figure out your “baseline mileage” and be more aggressive until you’ve reached that mileage level.

Higher Mileage Than Ever? Be Careful!

Be more conservative when you’re in unchartered territory. When you start running more than you have ever run before, you are in a potential danger zone. Your body has never run so many miles and a long adjustment period is probably necessary. If you’re running high mileage – anything over 50 or 60 miles per week – then you probably need at least 3-4 weeks of adjustment at each level before increasing.

If your legs are hurting more than you think they should, it’s time to listen to your body. Use a foam roller to massage your trigger points, take an ice bath, and make sure to continue doing the strength routines that enable your body to run a lot. If you want to focus more on self-massage I recommend a simple foam roller that isn’t overly expensive.

Personally, my danger zone is in the area of about 85 miles per week.  I can tolerate it, but that volume requires a long build-up and a steady adjustment period.  I wouldn’t increase my mileage over this level without at least 3 weeks of feeling great.

During my 12 year career, I have run 4 weeks at 90 miles.  One week during my sophomore year in college and a 3-week block of training before the NY Marathon in 2008.  After both, I got hurt.  Now I realize I have to be smarter with running volume at that level.  After all, 6 months at 75 per week is better than 2 weeks at 90 miles.

Running Mileage – the Big Picture

Ultimately, your mileage takes a backseat to the consistency of your training.  Running an extra 5 or 10 miles next week isn’t meaningful unless it is done for months. Instead of always trying to do more, try to run more consistently over the course of months and years.

Looking back on my own training, I kick myself for being impatient. Why did I so aggressively increase my volume in the past? Beats me. Maybe I thought that 80 miles per week was the secret to success.  Or 90…or 75.  There are countless times in my career when I got injured because I was impatiently chasing a number in my running log.

There is no magic number that will accomplish your running goals.  Focus on consistency, not making stupid mistakes, and only moving up your mileage when you’re ready and comfortable.  You may find yourself moving up by more or less than 10% but in the end, listen to your body.

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