Unfamiliar is different from uncomfortable
A new shoe can feel firmer, taller or more guided than the worn pair it replaces. That first impression deserves a short evaluation, but it does not justify a promise that every awkward sensation will disappear. The important question is whether the shoe is comfortable enough to use now.
An upper may become more flexible with wear, yet the basic length, platform shape and location of support do not transform. Do not buy a shoe that is too short or painfully narrow because someone says it will stretch into the right size.
Start with an indoor fit check
Wear your usual socks, loosen the laces fully and seat the heel before adjusting tension. Walk for a few minutes and notice whether pressure is localized under the arch, across the instep or at the collar. Those locations suggest different fit issues.
A lace adjustment can help a small pressure spot, but continually loosening the shoe until your foot slides is not a solution. If you use an orthosis, assess the intended combination from the start. Check whether the retailer permits indoor trials or running trials before taking the shoes outside.
Give the first run a simple job
Use the first outing to check the shoe, not to set a distance record. Choose a short easy route that lets you stop or return home readily. Keep the pace and surface familiar so you can notice the footwear rather than several new training variables.
Afterward, note whether anything rubbed and whether discomfort remained after removing the shoe. If the pair feels good, extend use according to comfort. There is no mandatory number of break-in miles, and extra mileage is not a sensible way to investigate a worsening pressure point.
Know when to stop experimenting
Stop using a setup that causes numbness, substantial pain or altered walking. Persistent symptoms deserve professional advice, especially if they continue without the shoe. New footwear can coincide with an underlying problem rather than being the sole explanation for it.
Avoid heating the shoes, aggressively bending the sole or cutting structural pieces to accelerate break-in. Such changes can damage the product and compromise returns without fixing the underlying fit. A different width, size or model is usually a clearer next comparison than trying to rebuild an unsuitable shoe at home.
Questions about this topic
Will a firm arch bump soften away?
It might feel different with use, but there is no guarantee. If it creates persistent pressure, choose a better-matched contour instead of waiting for pain to resolve.
How many break-in miles should I allow?
There is no required mileage. Judge short trials by comfort and fit, and stop if symptoms appear rather than aiming for a predetermined total.