When the 10% Rule for Increasing Running Mileage Doesn’t Apply

Sometimes it feels as though running and injuries go hand and hand. The more you run, the more likely you are to get injured. Why is that? There are so many rules to build mileage, but what is best for you might not be best for your friend.

Most sources state the ten percent rule is a good spot to start when increasing your mileage. It’s similar to BMI and while a good, very basic guideline, it’s not perfect for everyone.

BMI (body mass index) is often used as a “basic indicator” of health, BUT there are so many times that doesn’t apply.

Some people have more muscle.

Some people are healthier at a higher weight.

Every single person is different. Like BMI, the 10% rule is a good basic rule, but it’s not foolproof or perfect for everyone or every situation.

So First, What is the 10% Rule?

When starting running (or coming back), many sources state the best way to increase your mileage is by ten percent per week. So if you run 10 miles on week 1, run 11 miles on week 2. It’s not perfect and it doesn’t apply to every situation. But the 10% rule is a good basic way to increase your mileage.

When Doesn’t the 10% Rule Apply?

The 10% Rule Doesn’t Apply When…You’re Starting at Zero:

When you use the 10% rule for 50 miles a week, that’s 55. That is a doable mileage jump for most without getting hurt. When you start at 1 mile a week and add an extra mile, now you’ve increased 100%. Increasing your mileage by 100% might seem like you increased too quickly, but in that case it’s usually fine.

Usually, the 10% rule makes the most sense when you are already running 20 miles a week. 

The 10% Rule Doesn’t Apply When…You’re New to The Sport:

Hello…welcome! As a new runner, you want to run consistently and adapt to running. Remember, we were all new at some point. You might even consider hiring a coach or find a training plan to help guide you to what’s best for you. As a new runner you won’t know what works for you or what doesn’t work. Some people run every day; some people run once a week.

The 10% Rule Doesn’t Apply When…You’ve Been Injured:

No matter what your skill level, overuse injuries can occur. If you’re coming back from an injury, pay closer attention to your body. Don’t be afraid to walk-run. Don’t be scared to take more days off than you have before. Rushing back from an injury (sometimes even increasing mileage by 10%, could result in another injury).

How Can You Increase Your Running Mileage Safely?

• Make Your Extra Mileage Easy: You don’t need to sprint every mile. In fact, you shouldn’t. Make your extra mileage easy to keep your injury risk lower.  Pay attention to your heart rate and make sure you can have a conversation while running.
• Pay Attention to Your Body: I have a rule that if something hurts, aches, or doesn’t feel good for 3 days consistently, I will take time off. Rest days save seasons.
• Add Cross-Training: Cross-training can help keep your body stronger and more durable for additional miles. With cross-training, you’re increasing your weekly cardio but taking impact off your legs and body.
• Take Time to Adjust: Make sure to take a down week or recovery week every few weeks to let your body adjust to the new mileage. Down or rest weeks mean cutting out anywhere between 20-40% of your weekly mileage to recover.

Finally, always look at the end goal. Running should be lifelong. Nothing in running happens overnight, and by increasing mileage too quickly, you might find yourself injured. There is no best answer for how to increase your running mileage. Some runners flourish at 30 miles per week, and others flourish at 70. There are guidelines and rough ideas, but no perfect solution for everyone. It’s a trial and error process.

Finally, I wrote a Running Shoe Guide Ebook. If you’re interested, you can read here.

Questions for you:

How do you increase your mileage?

How many miles were you running when you set your PRs?