For almost 2 years, I have been reviewing a variety of running shoes. Can't believe I've already been writing on this blog for that long. During this time, I've set a standard for myself to review these running shoes only after extensive mileage. This gives me a chance to evaluate not only how the shoe rides over a variety of surfaces, workouts and conditions but also durability aspects of the shoe. I was also frustrated by other reviewers not being able to comment on long term durability and many aspects of the shoe that can change over time with wear and tear.
Up to this point, I set the minimum number of miles to review a training shoe at 100 and a racing shoe at 50. Over time I have had delays from the number of shoes I've been trying to get miles in on to the fact that I don't put enough miles on my racing flats to rack up 50 miles in an appropriate amount of time. This is one reason it took me several months to get around to reviewing the Saucony Type A6 (REVIEW).
The mileage cut off for training shoes was set from research I helped undertake in my undergrad at University of Puget Sound under Dr. Heidi Orloff investigating the effects of mileage and shoe breakdown based on changes in running kinetic and kinematic data. We found that all shoes, regardless of price or brand, held up their cushioning for approximately 100 miles. After that, the runner's body would compensate more and more for the degraded cushioning and wear patterns being worn into the shoe. This obviously depends heavily on the individual, their durability and biomechanics. Just as some people can compensate more, have better mechanics and can get more mileage out of their shoes (those people out there who claim to get +1000 miles out of a pair of shoes), others cannot compensate as much, may not have the best mechanics and get less mileage out of their shoes (including myself. I retire my training shoes between a max of 300-400 miles. Sometimes earlier).
This returns us to the age old question that anyone working in running specialty stores has been asked, "How long/how many miles before I should retire my running shoes?" 20-30 years ago people were told at 500 miles. Now in recent years, shoe companies will generally tell people in the range of 300-500 miles. Some, like Brooks, give even shorter durability of certain shoes like the Pure series (minimalist/transitional shoes) at 200-300 miles. Which is odd because I have gotten more miles out of my pairs of Purecadence series than almost any other shoe (+400 miles. It is extremely rare for me to take a shoe to that point considering how careful I am about overuse injuries and changing out my shoes). Again, it depends on the individual.
It may depend on how fast you put mileage on your shoes as well. I notice that the shoes I put mileage on slowly tend to last longer (not just time wise) than the ones that I rack up 300 mile week in 3 weeks or less. I do no know if the foam has more time to recover between runs and thus lasts longer, but it is something anecdotal that I have noticed. No research that I am aware of addresses this, but I would be curious to see how this factor effects shoe durability. So to get back to the point, the individual running 100 mile weeks will have to change their shoes out faster than someone running 10 miles a week. Not just from the mileage difference, but also due to the stress they are placing on the shoes and their bodies. This is why many shoe stores and footwear companies began suggesting that everyone have multiple pairs of shoes to rotate. It was believed that not only did putting less stress on each shoe make them last longer, exposing your body to slightly different stresses would help prevent overuse injuries (from being expose to the exact same stress repeatedly). That and they wanted another reason to move greater amounts of product to the consumer faster.
On the other end of the spectrum, many foams out there do degrade over time. I know this from personal experience finding many old and unworn running shoes in the back of both running stores I worked at and realizing the shoes don't feel the same as when they were debuted onto the market (almost ruined a pair of Nike Mayflys doing this....). So yes you can make shoes last a little longer by rotating several pairs, but know that over the years they won't be the same. This works better in terms of months, not years. The same applies to the individual putting 5 miles a week on their shoes. Yes they can get more time out of their shoes, but wearing the shoes for >1 year isn't a great idea. Not only is the individual exposing their body to the same stress repeatedly for a very long time, they are exaggerating certain movement faults due to wear patterns worn into the shoe. Over a few weeks this is fine and should cause too many issues. Over months and years? That's how people wind up with injuries. The body can only compensate for so long. We are what we repeatedly do. The amount of back, shoulder and lower extremity injuries I see in clinic from poor movement, posture etc is amazing. Oh wait... that's the reason behind the majority of orthopedic conditions I see. People don't get injured from good posture and great movement habits. They get injured from the exact opposite.
So for how long and how many miles should you wear your running shoes? At MAX 300-500 miles or 3-6 months depending on your mechanics . Some may get less, others may get more. I have retired training shoes at 200 miles due to poor durability and others at less than a month due to my high mileage. The best piece of advice I can give is to pay attention to how your body feels. If things seems off, you begin to get odd aches and pain, stop and evaluate why. Do these feelings only happen with that pair of shoes? If so then it's definitely time for a new pair. If the feelings happen regardless of the shoe (or even without the shoe), then it's time to head to your local physical therapist or medical doctor for an evaluation.
So we have all this talk about decently cushioning training shoes, but what about racing flats? That is a completely different situation. Generally racing flats are made to be very lightweight, close to the ground and minimal to allow for the individual to run faster without being weighed down. This general leads to decreased durability at the cost of high performance. Rarely do I get more than 75-100 miles out of my 5k-10k racing flats. Some of my half-full marathon flats can get in the range of 150-200 miles (like the Adidas Adios Boost 2, which some also consider a lightweight trainer), but they too don't usually get as many as traditional training shoes. Again, this will depend on the person and shoe.
Based on this, I will be reviewing my racing flats after 25-30 miles due to their decreased durability and to allow me to get a review out in a reasonable time. I do love racing shoes (currently have the New Balance MRC 1400v3, Nike Zoom Streak LT 3, and hopefully the Adidas Adios Boost 3 to review in the coming months) and hope to keep reviewing many as they tend not to be reviewed as often (mostly due to the larger public not having enough of an interest in running to invest in a lighter pair of shoes for racing).
Thanks for reading and hope everyone is having a happy holiday.
As always, my views are my own.
-Matthew Klein, SPT