How should running shoes fit?

It may vary by shop and brand, but return policies are often generous and allow you to return or exchange a pair of shoes within a period of time, assuming you haven't put too much wear and tear on them. A sales assistant will likely let you try shoes on either outside or on a treadmill, and they can perform a gait analysis to determine if you need a neutral or stability shoe. They can also help you choose the appropriate shoes for the surface you'll be running on, whether it's roads or trails.

When it comes to running shoes, you want to make sure you have enough room between your toes and the front of the shoes (about a thumb's width) to ensure they're not too small. Take it from someone who has experienced running in too-small shoes before: It's not fun, and you'll probably end up with bruised toenails or blisters.

You should have enough room to wiggle and spread your toes widely while you're running. Tingling or numbness in the toes is another sign your shoes fit too tight. If you've found you have wider feet than the average person, seek out shoes that offer a wide-fit option, as many brands do.

At the same time, you'll also want to make sure your shoes aren't too big or loose and your feet don't slide around while you're running. They should fit snugly, but not too tight, around your midfoot and heel, with comfortable cupping at the back of the heel. If you experience blisters or chafing above the back of your heel, you may also want to try running in higher cut socks, and make sure they're made of dry-fit technical fabric meant for running or exercise. When laced up, your shoes should be tied securely enough that the laces won't come undone mid-run, but not so tight that it causes pain on the top of your foot.

Another thing to keep in mind is that feet swell throughout the day, so it's better to try on shoes in the afternoon. Your feet may lengthen as your arches shift over time as well, so it's normal for your size to change in a given year. Additionally, if you wear orthotics for extra foot support or because you deal with a chronic condition like plantar fasciitis, make sure you bring them with you when trying on shoes in person, as you'll want to make sure your new shoes fit with them inserted as well.