How to Increase Running Mileage Safely

One of the simplest ways to improve as a runner is to run more. When executed smartly, increasing your weekly running mileage will make you a stronger, faster runner. When done incorrectly, ramping up your mileage will cause overuse injuries, lead to overtraining, and mentally burn you out before you even toe the starting line of your goal race. This article will guide you through how to increase running mileage safely – whether you are building from 10 miles per week or 60 miles per week. 

Why Increase Mileage?

Why is that higher weekly mileage often corresponds with faster running? There are multiple reasons why even small increases in mileage result in improved performance, such as enhanced running economy and improved aerobic capacity.

Higher mileage is in relation to your training. It does not matter how many miles your training partner or someone on Instagram runs, even if they run similar race times. Increasing mileage does not mean trying to run as many miles as possible per week. Not every runner will thrive running 60 or even 40 miles per week. You want to aim for sustainable growth over time. If you can increase from 15 miles to 25 or 35 miles to 40, you will improve as a runner. 

Increasing your mileage will yield significant gains if you are running lower mileage (twenty miles or fewer per week). If you carefully build from 10-15 miles per week to 25-30 miles, you will be faster and have more endurance, even without any speedwork. For runners who already run a good amount of mileage, a consistent increase of even just 5-10 miles more per week can lead to breakthroughs.

Increased Mileage Improves Running Economy

While we do not often view it in such a context, running is a skill sport. An elite runs faster, further, and more efficiently than a novice not because of genetics (although genetics can be a factor in VO2max) but because of training. The more hours you devote to running in a week, the more opportunity you have to practice the skill of running.

Chances are, running feels better when you consistently run 30 miles per week compared to 10 miles per week. Your stride becomes smoother, your musculoskeletal system becomes more resilient, your neuromuscular pathways communicate more efficiently, and your heart can pump more oxygen to your muscles. 

As a result of all those neuromuscular changes, your running economy improves. Think of running economy as a fuel efficiency, with oxygen as the fuel. The more efficient you are at any given pace, the less oxygen you need to sustain it. The more efficient you are at using oxygen, the longer and faster you can run.

Increased Running Mileage Improves Your Aerobic Capacity

The more miles you run, the better your aerobic system. There are many reasons for this. Firstly, in order to safely run more mileage, most of those miles need to occur at an easy pace. The combination of higher volume and easy pace running leads to a greater aerobic capacity.

Your body undergoes changes that make it easier to transport more oxygen to the muscles. Mitochondria biogenesis occurs, meaning that your cells have an increased capacity for aerobic metabolism. (The mitochondria of the cell – the “powerhouse” from biology 101 – is where oxygen is used to produce ATP.) Your body develops more capillaries to carry oxygen from the bloodstream into the working muscles. Aerobic enzyme activity also adapts to the demands, further improving your aerobic capacity.

Any running distance over 800 meters is predominantly aerobic. Having greater aerobic capacity will improve your performance in all distances over 800 meters – including the 5K, marathon, and ultras.

Related: Are you Running Your Easy Runs Easy Enough?

Increased Mileage Strengthens the Musculoskeletal System

Yes, there is a point where if you run too much, you do get injured. However, overuse injuries can also occur from running too little, and then attempting speedwork or doing a race.

When increased safely, running more mileage does strengthen your bones, muscles, and tendons. Both bones and soft tissues will adapt to small increases in running load, which makes them stronger over time. This adaptation is why new runners may get injured more often, but experienced runners will have lower injury rates even with harder training.

It should be noted that increased mileage alone will not protect against injury. Sleep, eating enough, rest days, and strength training all also impact bone density and soft tissue strength.

How to Increase Running Mileage

Figuring out how to increase distance in running can be harder than it seems. Many runners can fall into the trap of increasing mileage too quickly. What happens if you run too much too soon? Your chance of injury increases.

These outlined approaches are safe, sustainable approaches to increasing your mileage.

Increase Mileage During Your Base Building Phase

Base building is the ideal time to increase your weekly running mileage. If you can increase your year-round base mileage, your body adapts to handle more mileage. Then, when you start training for a race, you can tolerate higher mileage in training.

A base building phase is generally safer for increasing mileage, especially for injury-prone runners. During a base building phase, the overall training intensity is lower. You may only being doing some strides or very small workouts – no hard intervals or long tempos like you do preparing for a race. The lower intensity reduces overall training stress, which means that you can more safely increase mileage.

A base building phase is done when you do not have a race soon on the calendar. For example, if you are planning on running a fall marathon, you may spent late spring and early summer increasing your mileage. Dedicating a specific training block just to increase running mileage will reduce your risk of injury compared to trying to increase mileage while also doing race-specific workouts.

A base building phase can last anywhere from four to twelve weeks. The more you want to increase your mileage, the longer the base building phase should be.

Don’t Get Greedy; Do Gradual Increases

If there is one rule to increasing mileage, it is this: do not get greedy. Take your time. Focus on small increases first. Rapidly increasing from 20 to 50 miles per week results in injury or overtraining. Gradually increasing from 30 to 45 miles per week leads to sustainable growth. 

This is commonly referred to as the 10% Rule. The common rule of thumb is to increase your weekly running mileage by 10-15% every week (except cutback weeks). This method generally works well, although it is not infallible nor universal. Increasing by 10-15% per week may work well for runners who tolerate mileage well and are already running a higher volume per week. (If any increase seems challenging, here’s more about how to run longer.)

Another approach is the equilibrium method, popularized by renowned coach Jack Daniels. Rather than increasing incrementally each week, this method increases mileage by 15-25% and then maintains that mileage for 3-4 weeks. You then take a cutback week before jumping up again. The purpose is to allow your body to adapt to the stress of higher volume before adding additional training stressors. This approach benefits injury-prone runners and low mileage runners. 

For example, if you’re currently running 35 miles per week, increase your mileage (while keeping most of your miles at an easy pace or slightly decreasing the volume of your usual hard runs) to 40 miles. Stay in your new range for a few weeks and return to your normal intensity after the first full week of increased volume. After 3-4 weeks at this new volume, back off of your intensity and increase your mileage again, this time from 40 miles to 45 miles.

Decrease Intensity When Building Mileage

As noted above, a low-intensity training phase is an ideal time for increasing running mileage. If you do increase mileage during a race training phase, you can still lower your injury risk by decreasing your intensity.

A prime example of decreasing intensity when building mileage is training for your first marathon. You will not build up to your marathon training mileage during a base phase. The mileage in marathon training will be a novel stressor. To reduce injury risk, a training plan designed for a first-time marathoner will not feature the same sort of strenuous workouts that other marathon plans include. In some scenarios, a first-time marathon plan may feature only just easy-paced miles.

There are numerous different approaches for how to decrease training intensity when increasing mileage:

• Switch track workouts to hill repeats (which have lower biomechanical stress)
• Decrease the number of repeats in an interval workout
• Reduce the intensity of intervals
• Opt for less structured workouts such as fartleks or progression runs
• Decrease from two hard workouts per week to one hard workout

Take Frequent Cutback Weeks

You should be sure to include cutback weeks when you increase your volume. Cutback weeks are deliberate reductions in mileage, by anywhere from 15-50%. Cutback weeks allow you to recover and fully adapt to your new training load. Whether you are gradually increasing each week or following the equilibrium method, cutback weeks are a necessity. 

Running Mileage Build Up Schedule – Sample

Several variables will impact your exact mileage build up. Some athletes recover and adapt quicker than others, while others need to build slowly due to injury risk or medical conditions. If in doubt, opt for a slow conservative build. If you experience any pain or injury, scale back your build.

Curious about exactly how many miles you should run per week? Read this article on how to determine your weekly training volume.

These sample schedules demonstrate how you could build mileage when doing low, moderate, or high training volumes.

15-20 Miles (16-32 KM) Per Week Build:

• Week 1: 15 miles/24 km
• Week 2: 16 miles/26 km
• Week 3: 16 miles/26 km
• Week 4: 14 miles/17 km (cutback)
• Week 5: 17 miles/27 km
• Week 6: 18 miles/29 km
• Week 7: 18 miles/29 km
• Week 8: 20 miles/32 km

30-40 Miles (48-64 KM) Per Week Build:

• Week 1: 30 miles/48 km
• Week 2: 33 miles/53 km
• Week 3: 33 miles/53 km
• Week 4: 28 miles (cutback)
• Week 5: 36 miles/58 km
• Week 6: 36 miles/58 km
• Week 7: 38 miles/61 km
• Week 8: 40 miles/64 km

55-65 Miles (88-104 KM) Per Week Build:

• Week 1: 55 miles/88 km
• Week 2: 58 miles/93 km
• Week 3: 58 miles/93km
• Week 4: 50 miles (cutback)
• Week 5: 60 miles/ 96 km
• Week 6: 62 miles/100 km
• Week 7: 62 miles/100km
• Week 8: 65 miles/104km

Other Tips for Increasing Running Mileage

Focus on Progress, Not Perfection

Hiccups happen in training. You may need to take a few days off due to illness, a niggle, or work/life demands. You want to resist the temptation to cram miles into a few days to still achieve a weekly goal. If you need time off, take it and let your mileage decrease that week. The focus should be on a sustainable build over time, not hitting an exact number of miles per week at all costs. 

Assess How You Respond

Assess your training frequently. Are you being cautious by gradually increasing your weekly mileage and taking the right steps to recover well? Are your runs feeling good or are you feeling chronically fatigued? Do you feel excited to run most days or dread it?

Any increases in mileage should improve your running. Improvements are not just theoretical race day performances (such as thinking you need to run 70 miles per week to run a good marathon, even if it leaves you feeling like crap in your training). You should enjoy most of your runs. A majority of your runs should feel good. If you feel sluggish, constantly tired, or begin to dread training, then you want to decrease your mileage. No runner has ever raced well off of overtraining. 

Increasing Mileage is Different When You Have Run That Mileage Before

When you are rebuilding mileage to previous levels after a short reduction, you can increase at a faster rate than when achieving a new weekly mileage for the first time. For example, as an off-season or a brief layoff due to injury (up to eight weeks), you can increase back to 50% of your normal mileage and then 75% within a few weeks. (Read this post for more detail on how to safely return from an injury.) If injury, pregnancy, or burnout required you to take more than eight weeks off of running or you have only been running low mileage for more than a couple months, you want to increase more cautiously.

Be Patient

Increasing your running mileage may happen over the course of weeks – or it may be something you do gradually over a year. No matter which approach you take, be patient and do not get greedy for more mileage.

How Does Increasing Weekly Running Mileage Increase VO2 Max?

VO2 Max, a measure of your body’s ability to use oxygen during exercise, can be boosted significantly by increasing your weekly running mileage. As you run more, your heart muscle strengthens, which allows it to pump more blood with each beat. This means more efficient blood flow and that more oxygen can be transported throughout your system.

A higher VO2 allows you to sustain higher exercise intensities for longer periods without fatigue.

Increase Your Mileage While Running, Recapped

Successfully increasing your weekly mileage is a cornerstone of consistent running improvement. However, it’s crucial to approach this gradual process with patience and a focus on sustainable growth. Aim for small, consistent increases in mileage (10-15% per week) or utilize the equilibrium method to allow for adaptation. Incorporate rest days, adequate sleep, and strength training to support your body’s recovery and prevent injury.

Most importantly, listen to your body, as the optimal rate of mileage increase varies significantly among individuals.

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