Running shoe fit should get better every year. SmartLast testing of the recent release of Spring/Summer 2023 running shoes shows that fit is getting worse, especially for women’s fit. Let’s look at how fit is getting worse and some reasons why.

The graph above shows the SmartLast running database of almost 1500 women’s and men’s shoes from June 2021 through today. The 2023 averages for women and men are inside of the green normal fit sphere which is great! However, the ball fit has increased for both genders while toe fit remains the same.

This is a problem because ball of foot fit is a key part of shoe comfort, and looser fit is generally more comfortable.

Why would running shoes get tighter?

Through our work with running shoe fit, we know that the industry is not trying to make shoes tighter. In fact, many brands are working to make their shoes a little looser.

One explanation for the increase in tightness at the ball of the foot is brands are getting more creative with knit/mesh uppers. Many new styles have logos that wrap around the ball of the foot, especially on the lateral (pinky toe) side. These logos change how stretchy the upper material is, resulting in a tighter fit around the ball but not the toes. Also–these logos do not have the same fit impact on larger sizes as they do on smaller sizes.

How many shoes are fitting tighter?

This running shoe fit study evaluated styles from the top 20 running brands. 16 of the 20 brands have tighter fit in the ball of the foot in 2023 relative to 2022.

How much tighter are they (aka would the average consumer feel the difference)?

Women’s running shoes fit 3.6psi tighter (almost 1/2 size) while Men’s shoes fit 2.2 psi tighter (~1/4 size). Heeluxe’s human testing shows that most runners can perceive a 1/4 difference. So, yes, runners will be able to feel the fit difference in 2023.

How can we stop this trend in 2024?

There are 3 ways to change fit: lasts, materials, and patterns. Most of the brands we are familiar with have changed materials and patterns in 2023. To stop this trend, brands need to ensure their running shoe materials allow for ample stretch around the ball of the foot, particularly on the lateral side. Confirming that your shoes fit as expected prior to launch should be part of every running brand’s testing plan.

SmartLast is a fast and cost-effective solution that increases your confidence in fit results. Contact [email protected] to learn how to incorporate SmartLast into your product development.

How was this data collected on SmartLast?

All data for this report was collected in partnership with Running Warehouse or with shoes that the SmartLast team purchased from a retail store. No samples were factored into this data. Data was collected by 2 researchers using M9 and W8 US SmartLast sizes.