No matter how you get in your workouts - whether you run indoors or outdoors, take group classes, cross train, play team sports or more - you'll have to replace your shoes at some point. As you put more mileage on your workout or running shoes, the soles will begin to thin out, causing a loss of shock absorption over time. This diminishing support puts more stress on your joints and ligaments, which can lead to a myriad of nagging injuries including shin splints, achy knees and sore arches.
So how can you tell when to buy new workout shoes? It's not the easiest question to answer, because there are several factors to consider including your physical build, running style, training load and workout surface (e.g., asphalt, dirt road, hardwood floor, treadmill, tennis court, etc.). But there are a handful of general ideas to keep in mind that can help you determine when it may be time to retire your old sneakers and buy a new pair.
1. The Comparison Test
One quick way to determine if it's time for you to replace your workout shoes is to go to the shoe store and try on a new pair of the same shoes that you're currently using. If you can tell a significant difference in support and comfort--in other words, your old shoes feel completely flat in comparison to the new ones--it may be time to go ahead and buy a new pair.
2. Let Your Body Tell You When It's Time
It's not always accurate to determine if it's time for new workout or running shoes just based on the visible wear and tear on the soles. The midsole--the part of the shoe that provides stability and cushioning--will many times wear out before the soles show any signs of wear, causing a loss of support and lack of impact absorption. If you have been experiencing joint pain, shin splints or other discomfort in your upper or lower legs, your shoes may not be providing you with adequate support, and will more than likely need to be replaced.
3. Check Your Mileage
The average lifespan of a running shoe will be anywhere between 300 to 500 miles. This is admittedly a wide range, but several factors such as your training regimen, body weight and running style will all contribute to the amount of miles you can expect to get out of your shoes before it's time to replace them. Smaller runners will typically be able to squeeze more mileage out of their shoes, so their replacement threshold will be near the upper end of the range. Heavier runners can expect to replace their shoes closer to the lower end of the range. Running surface makes a huge difference as well; if you run primarily on asphalt, you will wear your shoes out quicker than doing an equal amount of mileage on a treadmill or other relatively resilient surface. You may want to keep an ongoing training log of the miles you've run and the workouts you've done, or you can mark your calendar every time you purchase a new pair of shoes so that you can have a point of reference as to when you first started using them for your workouts.
4. Physical Inspection
Perhaps the most obvious way to determine whether or not you should buy new workout shoes is to take a good look at their appearance. If the tread on the outsole has been worn thin and is slick on the bottom, or if the midsole is completely flat with hardly any cushion left, it's fairly safe to say that it's time to get some new shoes. If the tires on your car were worn down to the point of being bald, you would definitely replace them as soon as possible. The same principle should hold true with your shoes; if you're waiting until they are threadbare before replacing them, you're waiting too long.
The above guidelines should give you a decent set of parameters to help you determine when it's time to buy new workout shoes. Check out Five Seasons member and Be a Loser 2014 winner Mark Wright's blog post on getting a brand new pair of running shoes!