500 Miles

When is the right time to replace running shoes? (shout out to my pal Rob for this week's topic).

There is no one answer. The standard guideline is anywhere from 400-800 km, and this depends on a few different factors. 

The foam, how you run, where you run, how frequently you use the shoe, and the materials of the shoe all impact the life span of a shoe, and even then it can vary.  I have friends that can stretch shoes to 900-1000+ kms. I personally wlll replace shoes anywhere from 300- 500 kms - rarely do I run in a shoe for more than 450 kms. 

A main reason for getting rid of your shoe may be that holes have started to form and the shoe is breaking apart. You absolutely should not continue running in the shoe if this happen, even if the pair hasn’t hit the kms mentioned above. 

One of the first things I look for to determine if I am ready to call it quits on a pair,  is the quality of foam. When the shoe starts to feel “flat” and my legs start to hurt after a run, I know that this pair’s days are numbered. Another thing to look for is wear on the tread, especially uneven wear. Shoes tend to wear in certain areas more than others due to the way we run. Over time, the worn areas on the soles become pronounced and impact the feel of the shoe, possibly compromising grip,  and the risk of injury increases. This is when it’s time to ditch them.

Most daily-use running shoes have a variation of a certain type of foam called ethylene-vinyl acetate, or EVA for short. This foam is soft, durable, and resistant to water and UV damage.  Depending on the brand and the % of EVA used combined with other materials, durability can vary. I’ve had shoes that felt like bricks after 300 kms and some that just feel fantastic pushing 500 kms. All things considered equal, if a shoe starts to feel flat and is no longer enjoyable to run in, you’re probably better off replacing it instead of keeping it in the back of the shoe rack. 

The foam used in supershoes is a variation called polyether block amide or PEBA. This foam is very responsive but not very durable. Typically, the use case for shoes with this material is anywhere from under 100 kms (or 2 marathons) to several hundred kms. These shoes are not meant for daily use -  you may find that the sole will wear faster, and that the material is not as durable. While investing in a super shoe is a higher financial commitment than a daily-use shoe, runners should not extend the life of these shoes and maximize usage in them. This is where rotating shoes can be handy. 

I hope with the above pointers, you can spot the signs of when to replace your shoes to get the most out of your runs and avoid injury. Tread carefully. 

Workout Of The Week

4-6 800m repeats with 60 second standing rest. start at Half Marathon pace effort, 10k effort, 5k effort for the last couple of reps.