Running shoes should be a bit big and allow for your thumb to fit from the top of the toe to the top of the shoe. Your feet should not slip around, otherwise you could get injured.
Not Too Tight, Not Too Loose: Your Go-to Guide For Perfectly Fitting Running Shoes - Road Runner Sports
How Should Running Shoes Fit (15 Things to Consider)
How Your Shoes Should Fit – Aerobics First
How Should Running Shoes Fit?. Nike CA
How should running shoes fit and what are the best running shoes
Learn How to Find the Best Fitting Running Shoes
What's my size: How to properly fit running shoes
How Should Running Shoes Fit? Tips for Selecting the Right Pair
How Should Running Shoes Fit? The Ultimate Guide – Runner's Lab
Running Shoes, Free Shipping Orders $99+
How Should Running Shoes Fit?. Nike CA
How to Size Running Shoes: Tips for Finding the Right Fit
How Should Running Shoes Fit?
How to Choose the Right Running Shoe FOR YOU!
How Should Running Shoes Fit