How Often to Replace Running Shoes

The old rule of thumb was that you should replace your running shoes every 300-500 miles. However, that rule does not apply universally, especially in this era of booming shoe technology. Some shoes may last only 150-200 miles, while others may last 600+ miles. So how do you know how often to replace running shoes?

What Happens to Running Shoes with Time and Wear

Let’s first look at why you need to replace running shoes fairly frequently. Running shoes are comprised of three main components: the upper, midsole, and outsole. Each three parts of a running shoe can wear down over time. 

The midsole of a running shoe features a special foam that provides cushioning. With each step you take when running, you compress the midsole of the shoe. The compression is supposed to occur, as that is where you get the shock absorption and protection benefits from a running shoe. 

If you have a running cadence of 170-180 steps per minute and you go for a 45-minute run, you compress the midsole of your shoe 7650 to 8100 times in that single run. If you do five 45-minute runs per week, that add ups to 38,250 to 40,500 compressions per week. Running shoes do not have a set breaking point with compressions. However, this gives you an idea of the weekly wear and tear on your running shoes. 

Over time, the midsole foam loses its ability to rebound from repeated compressions. The foam can warp and lose its integrity – thus reducing the overall cushion and support of the shoe.  

The outsole and the upper of the shoe will also deteriorate over time. The upper fabric can develop holes or thin spots. On the outsole, the tread of the shoe can wear down over time. However, sometimes the upper and tread can stil be in good condition when the midsole foam has fully deteriorated. 

How Often to Replace Running Shoes?

Just like how the right model of shoes for you is highly individual, how often to replace running shoes is individual. Your biomechanics, the frequency of your training, if you rotate shoes, what type of surfaces you run on, and the model of shoes you are in will all affect how long a pair of shoes lasts. 

From observation, you will be able to determine how long your choice of running shoes lasts for you. Track the mileage on a new pair of shoes. Note when they start to feel less supportive and cushioned or when they show other signs of wear (more below). Note this mileage; that mileage is likely how long you can go before replacing your running shoes. 

Once you determine how long your model of running shoes lasts for you, you can use Strava, Garmin, a spreadsheet, or other apps to track the mileage on your shoe. Make adjustments based on the individual training cycle and shoes. For example, if you are doing lots of gravel/dirt road running in a season, you may get to 400 miles and find your shoes still have soem cushion left in them. 

Do Carbon Plated Shoes Need to Be Replaced More Frequently? 

Carbon plated shoes – also known as “super shoes” – feature a stiff carbon plate in the midsole. Many super shoes also feature ultra-lightweight midsole foam. These novel foams tend to deteriorate rapidly. Some super shoes may last only 100-150 miles. 

Super shoes should be reserved for racing and a few workouts within training. If you wear them very often in training, they will need to be replaced frequently. However, beyond cost, there are reasons you should not training regularly in super shoes. Carbon plated shoes are stiffer and do alter your gait, which may lead to higher injury rates if used on a frequent, consistent basis. 

Why Should You Frequently Replace Running Shoes?

Running in old, worn shoes is uncomfortable and increases your risk of overuse injury. Running shoes are designed to absorb some of the high-impact forces that occur when your foot strikes the ground. When the midsole foam no longer absorbs some of those forces, more impact is absorbed in your bones, muscles, tendons, and ligaments. 

Running in older shoes once should not cause an overuse injury. The risk increases if you consistently run in worn shoes for several weeks. Your musculoskeletal system will work harder to stabilize, which can increase risk of soft tissue injury. The increased impact forces may also be a tipping point for a bone stress injury, especially if other risk factors are involved. 

How to Know When You Need New Running Shoes

You cannot tell you need a new pair of shoes from the tread alone. The state of the outsole tread does not indicate the state of the midsole foam. Your tread may look worn down while the foam still has life to it or vice versa. 

You can, however, tell you need new running shoes based on how the shoes feel. Once they start to feel significantly less cushioned and supportive, the foam has likely deteriorated.

Warning signs that you may need to replace your running shoes:

• Your shoes feel objectively less supportive and cushioned compared to a new pair. 
• You start experiencing new mild aches and pains, especially in the feet and knees.
• Your shoes are starting to get holes in them.
• You are getting new blisters in places you previously did not with the same pair. 

How to Make Running Shoes Last Longer

You can make a pair of running shoes last longer! Alternating between two or more pairs, saving your shoes just for running, and taking care of your shoes will all extend their life. 

These practices will help your running shoes last longer:

• Avoid using carbon plated shoes for regular training. 
• Save your running shoes just for running. Daily wear, strength training, and cross-training in yoru running shoes will wear them down sooner. 
• Spot clean; never put your running shoes in the washer or dryer. 
• Store your shoes properly. Avoid leaving running shoes in hot cars or out in the rain/snow for prolonged periods. 
• If it is reasonable for your budget, rotate your running shoes. Rotating shoes allows the foam to decompress fully in between runs, which extends the life. (Rotating shoes offers other benefits, such as lower injury risk and having different shoes for different types of runs.)
• Reserve trail shoes for soft-surface running; the lugs will wear down more quickly on pavement or concrete.