Sunday, December 27, 2015

How Long Do Running Shoes Last and An Adjustment to My Shoe Review Mileage Requirement

     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

15 comments:

  1. I can never understand this. I retire my shoes when my toes start to come through the uppers.

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  2. hi, quick thoughts regarding streak lt 3 sizing? I'm currently wearing 9 most shoes, including the Hoka One One Huaka's and New Balance 1500v1

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  3. I went with my normal size 10 (mens) for the Streak LT 3 and they fit fine with socks. The mesh upper is stretchy enough that if you wanted to go sockless you might be able to a half size down but I wouldn't. Normal sizing fits fine.

    Hope that helps and thanks for reading!

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  4. From what I've been reading from your blog, and the people you refer to as being inspirational to you (Larson, Dicharry, et cet.), I am a bit puzzled about this latest blog entry.
    While I am no authority on that topic, I agree that shoes will be "done" sooner or later. However, what I cannot agree on after everything that I studied in regards to biomechanics, PT, and anatomy is that "proper" shoes prevent injury(ies). Shoes don't get you injured. Bad form, and mismatching F.I.T to your musculoskeletal system is what get you sidelined again, and again, and again. In reverse it stands to reason then that, with proper running form, and well trained muscles, tendons, and ligaments, shoes (old, worn, flat, whatever) won't injure a runner.

    I thought science of running was past putting the cart before the horse in regards to shoes?
    I know your intention with this entry was completely different. However, when I read it I got the feeling this article conveys alleged safety from running shoes to newcomers, and/or the uninformed: As long as I rotate, and replace my shoes regularly I will be fine. Which as we all know is a recipe for disaster.

    Please, do not take this the wrong way. I don't say you're wrong. On the contrary, everything you said is 100% correct (except maybe the part that EVA partly regains its cushioning when unloaded over a period of time but as you said the research on that is sketchy at best). After reading, I couldn't help but notice an aftertaste though that I thought needed to be addressed.

    Greetings

    PS. Oh, and looking forward to that LT3 review! The LT2 together with the Universe 4 are my favourite daily trainers.

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    1. Thank you for posting that! You are very correct in that what should come first is the strength of muscles and tendons, biomechanics, proper form and correct neuromuscular patterns. That SHOULD come first. And although that is what I follow, the general public does not. Nor do they have the interest and attention span to focus on the above until they are injured. Then they focus long enough on their rehab for their pain to decrease and they are back at it.

      This article was meant to be a quick blurb about why I was changing my shoe review mileage requirements to 75 for trainers and 25 for racing flats... but then I went on a tangent due to the number of individuals asking me this question recently.

      What I probably should have highlighted more is that if you are a tough individual with amazing form, strength and mechanics, you can probably get enough mileage out of your shoes to the point you bust through the upper of your shoe. Other individuals may be more sensitive to this for whatever reason (whether it is weakness, poor mechanics, higher joint flexibility, etc) that they are either unwilling to address or are unable to.

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    2. This post is very simplistic and does not address the larger aspect of biomechanics, strength, arthokinematics, neuromuscular patterns, neuroplasticity or any other part of the amazing human body to the degree they deserve.

      As I have said before, no shoe will prevent injuries but the wrong shoe can definitely contribute to one. It may not be the biggest component, but definitely a contributor. An older shoe that has heavy wear on the sole in specific places that bias certain abnormal movement or muscle firing patterns is not appropriate for an individual in running. Running is a high repetition activity that can lead to the creation of compensatory patterns very easily. Good or bad patterns can originate quickly rather quickly, which is why it is rare to see two runners who run exactly the same. Thus is the beauty of diversity of movement. No individual is immune to the risk of injury, they just may be able to fend it off longer.

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    3. I think what I am trying to say is that yes if your tendons, muscles, form etc are strong enough you may not experience an injury in whatever shoe you run in. The question is, is that shoe helping you be the best you can be? If it is emphasizing poor movement patterns in order to compensate for the body having to react to the same abnormal surface repeatedly, it would seem that you are sacrificing performance to just continue moving (somewhat) forward in any way one can. Perhaps because the medial forefoot of the shoe has worn down, the forefoot is placed in a greater everted position relative to the rest of the foot. This is not a normal position. If the foot was like this without the shoe, it would be a deformity. Due to the abnormal forefoot position, the peroneus longus must work harder to stabilize the first ray (metatarsal head) along with the flexor hallucis longus and brevis to maintain the anterior medial arch from collapsing beyond the normal without placing too much strain on passive structures. When fatigue sets in, you begin to pull the larger muscles of the rearfoot in to compensate for now poor mechanics at the forefoot. So the posterior tibilais must work harder to eccentrically control the motion of the mid and rearfoot due to it following the abnormal position of the forefoot. Higher stress on the posterior tib eventually means it gives out. When it can no longer compensate and then your larger muscles, ie the calves, must switch from being shock absorbing and propulsive muscles to stabilizing muscles (stabilizing is something the smaller muscles are generally better at due to better lever arms and biomechanical set ups). This continues up the chain until something gives. It may be within a few weeks or +10 years that this happens. The individual may not actually become injured, but they are probably not moving well.

      When wear patterns are worn excessively into shoes, the feet and lower extremities are placed in poor positions that they must endure repetitively. This is different from something like trail running, where your feet are being exposed to many different varieties of position due to constantly changing terrain. That also might be a reason to spend less time on the roads, which force more repeative motions than running on a trail. Regardless, shoes do not adapt like the body. They simply are and continue to be more of what is worn into them. Our bodies can rebuild themselves. A shoe cannot (although that would be cool and something I hope to see in the future).

      For someone like yourself who runs in minimal shoes, there is not much to wear down (my wave universe 4s lasted so long. They still are my favorite racing flats of all time). Versus a highly cushioned shoe that has more to break down and higher chances of excessive wear patterns being worn into them.

      So again you are very correct in that strength, form, mechanics, etc are extremely important. However, from a clinical standpoint, we must consider all factors when investigating either an injury or an injury risk. The foot, lower extremity and body react to whatever environmental conditions they are placed in. That includes the shoes we wear.

      Thank you so much for reading and your post! Always appreciate being forced to think!

      -Matt Klein, SPT

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    4. Can't believe I had to split that into 3 parts....

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  5. Agree with your thoughts here how long shoes will last. So much depends on how they are made, stack heights, how resilient the foam is (Boost for example holds form much longer) and yes the more minimal, basically they can be used until the upper shreds or outsole is gone since the shoe really isn't doing much. I personally do most of my reviews on shoes in the 35-50 mile range more just for a practicality of getting through shoes in a timely manner. Some shoes shoe hardly any wear in that timeframe and some would be substantially changed after 100 miles. Good posts lately Matt! Using your holiday break well :).

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  6. Hi Matt,
    thanks for getting back to me so quickly! As I said, I knew what your intention of this article was, namely to explain the change in mileage threshold for reviewing racing flats. That's why I really appreciate your taking the time to clear things up, and dive into the topic further. I sincerely hope I didn't offend you with my post.

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    1. No offense taken! I wanted to thank you for making me think! The above response is something I should add into the post. This is the transition that I am going through to becoming a clinician and very much appreciate you helping me.

      Thanks again for reading! Always feel free to comment!

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  7. Some heel movement is good as long as it is not making you uncomfortable. If you feel any irritation when you are trying the shoes in store, Reebok Discount

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  9. That's a really helpful article. Thanks for sharing it with us. It really helped me out. Like you rightly said good running shoes are equally important when it comes a hard core workout. I recently bought some online running shoes

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