This Is When You Need to Replace Your Running Shoes, According to 2 Experts

I've had the same running shoes since sophomore year of college. So, yes, they're long overdue for a replacement. If you're unsure whether or not your own sneakers need replacing, we've got you covered. POPSUGAR spoke to RRCA-certified running coach Marni Wasserman and podiatrist Miguel Cunha, founder of Gotham Footcare, for expert advice worth following.

When Do I Need to Replace My Running Shoes?

Most running shoes will get somewhere between 250 and 400 miles on them, Wasserman told us, but "it depends on a number of factors, including the terrain, how heavy you are on your feet, and if you're also wearing them for non-running activities." Dr. Cunha similarly said that "good" shoes are designed to last for 300 to 400 miles. So, he advised they'll need to be replaced every six months if you're running in them and every 10 months if you're walking. He recommends taking note of the date every time you buy a new pair, and Wasserman suggests apps like Strava and Garmin Connect that allow you to save your shoe info and mileage.

Another way you can check on your running shoes is by twisting them, Dr. Cunha explained. They should be firm, so "make sure they can't bend when you attempt to twist them." Also, if the soles are worn down and your shoes don't feel as comfortable as a new pair, those are signs that they should be replaced.

But Why Do I Need to Replace My Running Shoes?

"It doesn't matter if they still look new," Dr. Cunha said, "if the support has been worn out, you're at a much higher risk of injury." You can develop foot pain or shin splints as well. "I personally can tell when my shoes are starting to wear down because I'll start to have new aches and pains that bounce around both legs while running and go away as soon as I stop," Wasserman told us.

When asked if old running shoes can lead to infection, Dr. Cunha said, "Yes, but not because they are old, but because people don't care for them. The organisms that cause most foot infections [like athlete's foot, cellulitis, and plantar warts] tend to grow in dark moist areas, which is common in old running shoes that you have frequently poured sweat into." He further explained, "Plantar warts are caused by the human papilloma virus. Athlete's foot is caused by fungus, an organism similar to a mold, that feeds on dead skin and nails. Cellulitis is an infection caused by bacteria that may result in red, hot, swollen, and painful feet." He normally tells people to use Lysol Spray on their sneakers, shoe inserts, and shower floors to eliminate these germs.

When It's Time For You to Replace Your Running Shoes, Here's What to Look For

Dr. Cunha stressed the importance of finding a running shoe that actually fits because sneakers that are too tight can result in ingrown toenails and the progression of "bunion deformities." In stores, you can ask to use a Brannock Device (that metal foot-measuring contraption you've definitely used before) for both length and width. Generally, "the tip of your thumb should fit between the end of the shoe and the end of your longest toe. Make sure there is enough room to slightly wiggle your toes. If you can't move them at all, then the shoes are too tight and will eventually become painful." If you want to make sure the shoes you already have at home have a wide-enough forefoot (where your shoelaces start to the top of the sneaker), he suggests tracing your foot onto a piece of paper "at the end of the day when your feet are most swollen. Then, place the shoe over the tracing of the foot." If the shoe falls inside of your foot tracing, then it's too narrow.

"It is important to pick a shoe that offers as much durability and protection as possible without sacrificing comfort or flexibility," Dr. Cunha advised. "Look for a shoe designed with smooth, solid leather uppers that are not only highly durable, but also flexible and comfortable." Make sure the shoes are supportive and shock-absorbent, and have "a good bit of padding called an ankle collar," meant to protect and cushion the ankle and the Achilles tendon. You also shouldn't be able to bend a good sneaker; a shoe, as well as the heel of the shoe specifically, needs to be rigid for the best support. And, the flex point of the shoe (where it bends and creases) should match the bending point of your foot, he said.

Sizing can be different across brands because of the design of the shoes and material used, Dr. Cunha noted. To compare, he recommends trying at least three different shoe models total, as well as two different models at the same time. Go to stores that specialize in running shoes "where the staff is better informed and knowledgeable about choices and recommendations and will have more time to spend with you individually as a customer." Bottom line? There's a long (long) checklist when it comes to what a "good" running shoe is, but it's important for your foot health and safety.