It is generally accepted that the cushioning properties of running shoes deteriorate after about 1,000 kilometers. In practice, however, this varies from person to person — cushioning wears out gradually, so it’s hard to determine the exact moment when shoes are only suitable for the garden. The rate of wear is influenced by many factors, so the best answer to the question, “When should I replace my shoes?” is, “It depends.”
Why 1,000 kilometers?
It is commonly accepted that the cushioning in a running shoe lasts for about 1,000 kilometers. This average is based on observations and the experience of runners. Manufacturers do not provide this information, so it is impossible to specify how many kilometers a pair of running shoes will last. It is impossible to say that a given foam will lose a certain percentage of its cushioning after a certain number of kilometers. This value varies from person to person, and just as manufacturers do not want to take any risks by providing this information, I am also unable to provide it to you.
What extends and what shortens the life of a shoe?
- A runner’s weight affects how quickly foam and other cushioning systems lose their properties. Lighter runners put less pressure on the midsole with each step, so the material loses its properties more slowly. In this case, lighter runners have a slight advantage. Due to their lighter weight, they “break in” their running shoes more slowly, and their cushioning lasts longer.
- The average lifespan of a pair of shoes is 1,000 kilometers, and this primarily applies to training shoes, which are designed for cushioning and have a more solid upper. Racing shoes have less cushioning, so they last for a shorter time. There are also issues related to the foams used; their lightness and elasticity affect durability. Racing shoes rarely exceed 1,000 kilometers, and are more likely to last 400–500 kilometers. For the most advanced models, the lifespan is reportedly around 200 kilometers.
- Terrain and outdoor conditions can put a lot of strain on shoes, but they do so in completely different ways. Although trail shoes do wear out when their cushioning is depleted, this is not how they typically fall apart. Trail shoes usually fall apart “from the top.” Mesh uppers do not fare well against sand, stones, mud, or clay. Although trail shoes often have uppers made of more durable materials, even these reinforced shoes will not last forever.
How does a shoe wear out and why can’t you see it?
Unfortunately, you can’t see cushioning wear with the naked eye. Additionally, there is no single moment when a shoe suddenly loses its softness. The process is gradual and occurs with every step, so you may not even notice it. This is why many runners think that shoes are still suitable for running even after several years if they look intact on the outside. Unfortunately, this is a false impression.
A well-made shoe can look almost new after 1,000 kilometers. It may also look almost new after 2,000 or 3,000 kilometers. However, even though such a shoe may look fine, the foam used to make the midsole has long since lost its shock-absorbing properties. The foam underfoot is still there, but it no longer flexes or cushions. Runners with shoes like this say they are “worn out.” They may not look worn out, but for the sake of your health, you should replace them.
Unfortunately, this cannot be determined at first glance, nor is there a tool for doing so. The best approach is to simply pay attention to how many kilometers you run in a given pair of shoes. If these are your only running shoes, it’s easy because you probably count the kilometers you run. If you have more than one pair of shoes, it is worth using an app to track how many kilometers each pair has covered. Strava, for example, has such a tool. The closer you get to 1,000 kilometers in a pair of shoes, the more you should consider buying a new pair.
Your impressions can also be a sign that your shoes are worn out. You may feel that what you have under your feet is no longer soft, and that the pavement has become harder than it was six months or a year ago. This can cause pain because your body has to take on more of the cushioning that the shoe would normally provide. These are signs that your shoes are worn out and you should look for a new pair.
What to do when your shoes are worn out?
Are running shoes that have lost their cushioning properties only good for the trash? Not necessarily.
They can become your “pair for a rainy day.” This could be for rainy days, slush, mud, or other conditions when you know your shoes will get dirty quickly. You may not want to ruin your favorite training shoes in such conditions. I don’t mind using an old pair of shoes in those situations.
Worn-out shoes can also become everyday shoes. Just because they have lost most of their cushioning doesn’t mean they’re not comfortable. They’re too worn out to provide enough cushioning for running, but after a thorough washing—sometimes in the washing machine—they can be very comfortable for everyday walking. They are often more comfortable than most so-called “everyday” shoes.
Summary
The lifespan of running shoes depends on various factors, including the runner’s weight, the type of shoe, and how they are used. Although it is often said that shoes should be replaced after about 1,000 kilometers, the loss of cushioning is gradual and difficult to notice. Therefore, it is a good idea to monitor your mileage and pay attention to how your shoes feel when running so that you can replace them at the right time and avoid injury.
