“I told SELF magazine that 400 miles is the classic replacement point, but the real signal is what your body is saying. If the tread is worn, the foam feels dead, or you have new aches, the mileage number is just confirming what you already know.”

“400 miles is right where I start paying attention, not automatically tossing a shoe. I rotate pairs and retire most around 400 to 500 miles, but how the foam feels and whether anything aches matters more than the number. If your legs suddenly feel beat up after easy runs, the shoe is probably done.”

“Look at the midsole for compression and creasing, the heel counter for distortion, and the outsole for worn tread and separation—replacement is reasonable when traction has dropped, the platform has tilted, or a familiar symptom appears in the worn pair but not in a fresh one of the same model.”

“I don't track miles on my shoes, and I think most runners replace them too early. If they're not hurting you and the midsole still feels alive, 400 miles is a suggestion, not a deadline.”

“At 400 miles the midsole foam is likely compressed enough that you're no longer getting the cushioning your joints need, especially since running can load each footstrike with two to three times your body weight. I wouldn't wait for visible wear: replace them now, and consider rotating two pairs so you always have a fresher shoe in the mix.”

“The 300-500 mile guideline is real, and at 400 miles you're right in that window where the foam starts to break down without looking worn. I usually push mine past 500, which I probably shouldn't admit, but if anything feels flat or your knees are talking to you, that's the shoe telling you it's done.”

“400 miles is usually where I start feeling the shoe flatten out, especially if I’m doing hard workouts on pavement. If your calves or knees are talking to you more than usual, that’s the shoe telling you it’s done.”

“Don't rely just on a mileage number.”

“I’d replace them, but not because of the mileage number. I look at how the shoe feels: once the midsole goes dead or my knees start talking, the shoe is done, and I learned the hard way that running in worn-out cushioning beat up my joints more than the ground did.”