How often should I replace my running shoes?
Sport & activity
Here's what experts have to say about the lifespan of your running shoes—and when to swap in a new pair.
When it comes to the question of how often to replace running shoes, the general recommendation is switching them out every 300 to 500 miles, said Carol Mack, DPT, CSCS.
But, that short answer doesn't take all the variables into account. For example, factors like a worn-down shoe sole or fresh blisters on your toes may indicate that running shoes are well past their prime.
"What's helpful is understanding signs of wear that should lead to replacement, which includes both the shoes themselves as well as how your body is responding if your running shoes are becoming worn out", Mack said.
This can be especially helpful if you don't track your miles, she added, which means being mindful of other key factors, listed below.
When to replace running shoes: 5 signs to watch out for
1. The wear pattern is uneven
Sometimes, just a glimpse at the bottom and sides of the shoes is enough information to know when to replace running shoes. To some degree, a worn-down tread is common but when the wear and tear is uneven, potential issues can arise. For example, you may notice more wear on one shoe than the other, or, more commonly, wear will be increased on a specific part of both shoes—like breakdown on the outer edge but not the inner edge.
"When wear patterns are uneven, that could cause alterations in the running stride itself", Mack said. "For instance, that can accentuate asymmetries in a person's running gait and create instability".
As a result, this could cause aches and discomfort because your body is trying to compensate for that uneven pressure, she added, causing you to move in a less efficient way. If this goes on long enough, it could affect your joint stability, Mack said.
2. You've owned the shoes for a long time
If you're not running long distances and focusing more on workouts like hill repeats or athletics, using time might be a more effective measure than miles run, according to Jason Machowsky, CSCS, clinical exercise physiologist. This is especially true if you rotate between another pair of shoes during a training cycle.
If time is what you're using to determine when to swap them out, the lifespan of a running shoe is usually three to six months, Machowsky explained, but that could be longer if you run occasionally or shorter if you're training for a marathon. For example, some marathon or ultra-marathon runners might log upwards of 50 miles per week, which means they might be replacing shoes more often than someone who enjoys crushing an occasional sprint workout.
3. The shoes have lost their bounce
If a run that once felt easy now seems like a slog, it may be due to factors like inadequate sleep and nutrition or even overtraining syndrome. But it could also be your shoes, Mack suggested. With worn-out shoes, the inner foam has started breaking down, creating less of that "lift-off" quality that helps cushion continuous impact.
"You can feel this either as you run or when you push into the shoe itself", Mack said. One way to tell is by pressing a finger into the midsole inside the shoe. If it feels spongy, there's still appropriate cushioning, but if it's flat or compressed, that could be a sign that you need to freshen up your shoes.
4. You're more sore than usual
One major way to tell when to replace running shoes isn't about the shoes themselves, but their effect on your body.
Soreness in the joints—that wasn't part of your previous running recovery—is a telltale sign your shoes may be ready for retirement, Machowsky said. This can affect any joints, including the ankles, knees, hips, lower back and even the neck, since running in worn-out shoes may be changing your posture and gait.
5. Blisters are popping up on your feet
Blisters are often the most notable sign that it's time to swap out your running shoes, Machowsky said.
Although blisters are also often associated with new shoes, they can also start appearing when running shoes are worn out enough to change foot position and movement (even slightly) during a run. Without as much support and cushioning, your feet tend to move around in the shoe more, creating hot spots on the foot where skin is rubbing against the fabric.
Why it's important to retire an old pair of shoes
Even if you're not experiencing signs like joint aching or instability, running on worn-out shoes can raise your risk of overuse problems, Machowsky said. Running shoes are designed to support the feet and absorb some of the forces that come with repetitive impact. When that's not happening, more of that impact reverberates through the body—over and over again.
"Those forces can get channelled to other areas of the body such as the foot, ankle, leg or even lower back", he said. "This can be due to increased forces or change in how the body is moving in the shoe".
For example, loss of cushioning can lead to greater foot collapse or pronation, adding to stress in the feet, ankles and shins.
In addition, loss of tread on the soles can increase your risk of falling, especially if you're running on wet pavements, dirt tracks or icy roads.
Consider training in two pairs of shoes (minimum)
As a way to extend the life of a single pair of running shoes, one tip is to use them only for running, rather than making them all-purpose workout or casual shoes, Mack said. For instance, some runners keep an alternative pair of old kicks in the car so they don't wear their running shoes on errands or for other everyday tasks.
Another strategy: some runners will alternate use of two pairs or more, Machowsky said. This doesn't just push off the purchase of a new pair; the strategy may also contribute to injury prevention, he added. To clarify, alternating between two pairs of running shoes—whether they are the same type of shoe or one is designed for speed work and the other is for long distance—can help extend the life of both shoes. This way, you don't have to buy new ones as frequently.
"Some of the value in alternating shoes may not necessarily be related to prolonging the life of the shoes but in varying the forces or loads on the body", he said. "Since running is a very repetitive sport, overuse injury is common. Something as simple as the subtle change in forces when wearing different running shoes can spare different muscle groups and possibly lead to a reduced risk of injury".
Also, when it's time to change one pair, you'll have the other pair already broken in. This can make the switchover easier than starting anew with just one pair of running shoes. Plus, added Mack, you don't have to toss the old ones: they may not be supportive for logging miles in a run any more, but they're usually still valuable for everyday tasks like gardening, going shopping or taking a leisurely walk.
Words by Elizabeth Millard, ACECPT