What is the 10 rule of running?

Understand the 10 percent rule of running

If you have ever wondered what is the 10 rule of running, you are not alone. The 10 percent rule is a popular guideline that suggests you should not increase your weekly running mileage by more than 10 percent at a time. The idea is simple: steady, gradual progress helps you build fitness, lose weight, and improve your health without overloading your body.

This concept was popularized in the 1980s by Dr. Joan Ullyot and writer Joe Henderson. They wanted a clear, easy rule that would help runners avoid common overuse injuries as they added more miles to their training (Runner’s World).

In practice, the 10 percent rule looks like this:

If you run 10 miles this week, you aim for no more than 11 miles next week.
If you run 20 miles this week, you cap next week at about 22 miles.

The rule focuses on your total weekly mileage, not a single run. It is designed to keep you from going from “a few miles here and there” to “way too much, too soon.”

Why the 10 percent rule became popular

The 10 percent rule caught on because it is:

Easy to remember. One simple number, no math degree required.
Beginner friendly. It gives you a clear ceiling so you do not jump from 5 to 15 miles in a week.
Injury aware. Gradual mileage increases give your muscles, joints, and tendons time to adapt.

When you are using running to lose weight or support your overall health, consistency is more important than any single “big week.” A moderate increase in weekly mileage can help you:

Burn more calories over time
Build cardiovascular endurance
Strengthen bones and connective tissues

By nudging your mileage up instead of making giant leaps, you are more likely to stay healthy enough to keep training.

What research actually says about the 10 percent rule

The 10 percent rule sounds sensible, but what does the science say about it?

Mixed results from injury studies

Research has not been as clear cut as the rule itself.

A Dutch study in 2008 found that about 20 percent of runners got injured whether they increased their mileage by 10 percent or by as much as 50 percent per week (Runner’s World). That suggests that simply sticking to 10 percent does not guarantee you will avoid injuries.
A 2022 study in the British Journal of Sports Medicine followed runners training for the New York City Marathon. Those who exceeded the 10 percent rule did not have more injuries than those who followed it closely. What did matter more was their acute-to-chronic workload ratio (ACWR). When that ratio rose above 1.5, the injury risk went up (Runner’s World).

In other words, your risk seems more closely tied to how quickly you jump above your usual training load, not whether the increase is exactly 10 percent or not.

A helpful guideline, not a law

Sports scientist Tim Gabbett has suggested that the 10 percent rule should be treated as a guideline, not a strict code of conduct (TrainingPeaks). His work and others point to a few key ideas:

Well trained recreational runners can sometimes tolerate larger short term increases, around 25 percent, but only for one or two weeks at a time (TrainingPeaks).
In one six month study, the median maximum weekly increase among 26 well trained runners was about 30 percent, and only 2 runners stayed at or under 10 percent (TrainingPeaks).
Most runners naturally fluctuate. About 73 percent of runners in that study at some point increased their weekly load by more than 20 percent, typically followed by easier weeks (TrainingPeaks).

So you can think of the 10 percent rule as a conservative starting point, not a magic number that fits every situation.

Pros of using the 10 percent rule

Even with its limitations, the 10 percent rule has real strengths, especially if you are newer to running or coming back after a break.

Simple guardrail against doing too much

If you are excited about losing weight, improving your cardiovascular health, or training for your first race, it is easy to get carried away. The 10 percent rule:

Gives you a clear upper limit when motivation is high
Reduces the temptation to double your mileage overnight
Keeps your training progress structured and predictable

Lower risk of common overuse injuries

When your weekly mileage grows slowly, your body has time to adapt. This can help you avoid issues related to ramping up too quickly, such as:

Shin splints
IT band syndrome
Plantar fasciitis
General joint pain, especially in the knees and hips

These injuries do not usually come from one hard run. They build over weeks of doing more than your tissues can handle. A gradual increase in volume makes that less likely (Runner’s World).

Good starting point if you like structure

If you enjoy clear rules, the 10 percent guideline can make training feel less confusing. You know exactly how much to add, so you can:

Plan your weekly schedule
Track your progress in a log or app
See your fitness build steadily over time

For many runners, especially those focused on weight loss and health, that sense of structure can be motivating.

Cons and limitations of the 10 percent rule

Despite its popularity, the 10 percent rule is far from perfect. It leaves out important pieces of the training puzzle.

It only looks at mileage, not intensity

The rule focuses purely on distance. It ignores key variables that affect how stressed your body feels, such as:

Pace and workout type, easy jogs versus hard intervals
Terrain, flat pavement versus steep hills or trails
Environmental factors, heat, humidity, or altitude
Life stress, sleep quality, and overall fatigue

You could follow the 10 percent rule, but if you add more speedwork, steeper hills, and less sleep, your injury risk can still climb sharply (Medium).

It may be too slow for beginners

If you are just starting and running only a few miles per week, 10 percent increases might feel painfully slow. For example:

Week 1: 5 miles
Week 2: 5.5 miles
Week 3: 6.1 miles

If you are eager to use running to support weight loss and you feel good, you might safely handle slightly bigger increases at first, as long as you mix in rest and easy days.

It may be too aggressive at higher mileage

On the other end, the 10 percent rule can actually become too aggressive when you are already running a lot. Jumping from:

40 to 44 miles, or
50 to 55 miles

is a significant extra load. Your body might not adapt well to that size of increase every single week, especially if you keep stacking those jumps.

It ignores how you feel

Strictly following any rule can make you tune out your own body. The 10 percent rule can:

Discourage you from backing off when you feel extra sore or tired
Make you feel like you are failing if you do not increase every week
Overshadow important signals like persistent aches or heavy legs

Listening to your body is a key part of healthy, sustainable training (Medium).

It does not scale sensibly long term

If you tried to add 10 percent every week for months, your mileage would skyrocket. One analysis pointed out that a steady 10 percent weekly increase over 12 weeks would lead to about a 135 percent increase in total mileage, which is unrealistic for most runners (Medium).

Real life training works better in waves, with heavier weeks followed by lighter ones, rather than an endless upward climb.

How to apply the 10 percent rule in real life

Instead of asking only what is the 10 rule of running, it helps to ask, “How do I use it in a way that fits my body and my goals?”

1. Use it as an upper limit, not a requirement

Think of 10 percent as a ceiling, not a target you must hit every week.

Some weeks, you might increase by less than 10 percent.
Other weeks, especially cutback weeks, you might even run less.

You do not need to go up every week to get fitter, lose weight, or improve your health. Your progress can still be steady if you allow gentle ups and downs.

2. Match increases to your current level

You can adjust how strictly you stick to the rule based on where you are:

If you are a beginner: You can use the 10 percent rule as a safety net, but you can also add time through walk-run intervals instead of only chasing more miles.
If you are intermediate: You might follow the 10 percent guideline for most weeks, then build in a lighter “recovery” week every third or fourth week.
If you are well trained: You may occasionally increase by 15 to 25 percent for a short period, like one or two weeks, then bring the mileage back down, similar to what researchers observed in recreational runners (TrainingPeaks).

3. Pay attention to your total training stress

When you increase your weekly mileage, keep other stressors under control:

Keep most runs at a comfortable, conversational pace.
Introduce only one major change at a time, for example, more miles or more speed, but not both in the same week.
Be cautious if you change terrain, for example, moving from flat paths to hilly routes.

If you had a week with poor sleep, high work stress, or lingering soreness, even a small mileage increase might feel like a lot.

4. Watch for early warning signs

Your body usually gives you hints when you are edging toward overuse. Slow down your increases or hold steady if you notice:

Pain that worsens as you run instead of easing up
Soreness that does not fade after a day or two
Heaviness or fatigue that lingers through easy runs

Backing off when you notice these signs will not derail your progress. It will protect it.

5. Combine running with other healthy habits

If your main goal is weight loss or improving overall health, running is only one piece of the puzzle. You can support your progress by:

Prioritizing consistent sleep
Eating enough to fuel your runs while maintaining a modest calorie deficit if weight loss is your goal
Including light strength training to support your joints and improve running form

That way, you do not feel pressured to increase your mileage aggressively just to see results.

A smarter way to think about “10 percent”

You can sum up a more realistic approach to the 10 percent rule like this:

Use 10 percent as a simple guideline when you are not sure how much to add.
Adjust based on your experience level, how your body feels, and what else is happening in your life.
Remember that intensity, terrain, and recovery matter as much as mileage.
Accept that training should ebb and flow, with easier weeks built in.

If you keep asking yourself, “Can my body handle just a little more than it did recently?” you are already thinking in the right direction, even without perfectly following the rule.

You do not need to follow the 10 percent rule perfectly to become a stronger, healthier runner. Use it as a starting point, listen closely to your own body, and let your progress unfold gradually.