How long have you been exercising or running in your pair of trainers? According to experts, if you've been using the same pair of shoes for more than three to four months, then most likely you are causing damage to your feet and back. However apart from the time factor, there are other signs you should be looking for - as everyone has a different body mass and would wear out a shoe at different time spans. According to Dr. Michael Lowe, of the American Academy of Podiatric Sports Medicine (AAPSM), the most important wear factor for a running shoe or court shoe, is compression fatigue of the mid-sole material (the material between the sole and the upper leather). "Like any compressible material, it has a certain life expectancy, after which fatigue begins to lessen its efficiency and ability to decrease impact forces," said Lowe.
Another factor in assessing if you need to replace your trainers is to look for excess wear on the bottom sole - especially if your feet have a tendency to pronate (roll to the inside) or supinate (roll to the outside), which will cause one side to wear more than the other. "Wear patterns can also be helpful in evaluating an athletes' biomechanics and what shoes may work best for them," says Dr. Phyllis Ragley, past President of AAPSM. "Shoes can also become slick and lose traction when the soles and lugs are worn down, so that is something else to keep an eye on." The experts also recommend that persons check the inside liner of their shoes for areas which may be worn through. This may provide information about places where the shoe was causing excess friction.
Running Shoe FAQ
When is it time to retire my running shoes?
Between 300 and 500 miles. Why the range? Because how quickly a shoe wears depends on you. If you land hard on your heels with each stride, for example, you're going to wear through shoes more quickly than more efficient runners. Go by feel. If after a normal run your legs feel as if the shoes aren't providing you adequate protection, they probably aren't. Give your legs a week to make sure it's really the shoes and you're not just tired. If the shoes still feel dead, replace them. When you can see white midsole material poking through the outsole or when the sole under the heel looks crushed, the shoes are long past their prime.
Is alternating two or three different shoes for training better for your feet?
Running in more than one pair will help your biomechanics adapt ever so slightly to each shoe. These adaptations are a good thing because they help prevent overuse injuries. In addition, midsole foam requires as long as 24 hours to fully recover from a run. So if you run at night and then need to get an early workout in the next morning, a different pair will give your body more protection.
Does the surface you run on affect how your shoes break down?
Road running will make your shoes wear faster than trail running, for sure, but the way you run is an even bigger factor. A 200-pound heavy heel-striker who runs exclusively on trails will most likely wear out his shoes well before a 100-pound biomechanically efficient road runner. If you are worried that your shoes are ready for retirement, take a close look at them. If the upper appears pulled or stretched so that the foot is sliding off the midsole, or the grooves on the outsole are worn smooth, it's time for new running shoes.
I noticed that during long runs in my motion-control shoes, the balls of my feet hurt. Does this have anything to do with my shoes, my gait, aging, or all of the above?
As we age, the natural cushioning of the foot starts to lose its resilience, which means shoes with good cushioning are especially important for older runners. To address your sore feet, look for a shoe with good support. If you're lighter weight (under 160 pounds), consider moving from a motion-control to a stability model.
