Last updated on February 16th, 2024
Whether you're racing a 5k or enjoying a leisurely ultra-marathon, a reliable pair of shoes is essential. We all know the struggle of breaking in new running shoes, but once they fit like a glove, how long can they maintain that level of comfort before they become worn out? And when they do, how does that affect our bodies and running style?
Research shows that worn-out shoes can alter our posture and gait, putting us at risk of injuries. As the super-shock-absorption abilities of our shoes decline, each step becomes more challenging.
However, how can you be certain that you have reached this stage in the lifespan of your footwear? I understand the difficulty of parting ways with running shoes that have accompanied you during your initial race or marathon, but it won't be long before they become more of a hindrance than a support. If you wish to continue running, it is crucial to grasp when it is time to bid farewell.
What is the lifespan of running shoes?
When it comes to running, the duration of your shoes is determined by the miles you cover, not the months they've been in use. By doing some calculations, you can estimate the lifespan of your shoes.
As time passes, it is inevitable that we all age - and the same goes for our trusty running shoes. However, it is worth considering the significance of giving them ample rest (and yourself too).
Recent research from 2020 explores the impact of resting running shoes for 22 hours after every 20 kilometers of running. The study revealed that the rested shoes exhibited a greater ability to absorb energy during the initial 10 kilometers of the subsequent training session, in comparison to those that were not rested.
In essence, the message here is simple: reserve your running shoes solely for running purposes and allow them the opportunity to rest and rejuvenate. Failing to do so will result in a rapid decline in their lifespan.
If we assume that your running shoes are solely used for running and not for activities like walking the dog, going to work, or playing with the kids, we can begin to examine the mechanical aspects that determine their lifespan. Specifically, let's consider the wear and tear caused by the repetitive compression of the midsole with each step.
Additional research indicates that running shoes generally endure for a distance of 300–1000 km (equivalent to 200-600 miles). Quite a rough estimate, right?
The durability of a runner's shoes is greatly influenced by their specific design, how they are used, and the individual's training regimen. As the shoes gradually wear down, the runner's unique stride and the resulting pressure on the soles may also shift, significantly affecting the longevity of the footwear.
The New Balance 738 model piqued curiosity when it underwent a rigorous 700km (434 miles) testing phase, exclusively with male runners. It is worth pondering whether the female version would fare better, given that women tend to be slightly lighter on average. However, we cannot definitively say. The plantar pressure remained steadfast and supportive throughout the testing, but the midfoot pressure experienced an uptick due to the wear and tear of materials and a decline in cushioning systems.
After subjecting different models to a 500km (310 mile) run, it was observed that the plantar pressure increased by a significant 100%. This is certainly not a favorable outcome. Furthermore, the shoes displayed evident structural damage on their outer surface, with noticeable holes and wrinkles, after covering a distance of 750km (466 miles). The impact of this damage cannot be overlooked.
Based on our research, we have discovered that around the 300-400 mile mark of your training, there are significant mechanical changes that occur within your shoes. It appears that this is the ideal time and distance to transition to a new pair if you are committed to preventing injuries and optimizing your performance.
It is crucial to remember that running shoes age and deteriorate, leading to issues such as foam fatigue, increased pressure on the forefoot and midfoot, and reduced cushioning in the heel strike. Any of these factors could potentially cause running injuries.
What about minimalist running shoes without cushioning?
When should consider replacing running shoes?
According to Brookes, Nike, and ASICS, their shoes are specifically engineered to endure a distance of 300-500 miles, which corresponds to approximately 3-6 months if you maintain an average weekly mileage of 20 miles.
However, marathon runners may find themselves needing to replace their shoes earlier than others due to their higher weekly mileage of 40-50 miles.
Additionally, road runners will require more frequent shoe replacements than trail runners, just as overpronators will need to repurchase running shoes more frequently than neutral runners.
What are the indicators that it's time to search for new running shoes?
The treads on your shoes have been eroded, causing you to struggle for traction while navigating through muddy terrain.
Under minimal force, the mid-sole displays an excessive softness, resulting in its collapse.
Toes gradually piercing through the front part of the shoe.
Does the overall condition of the shoes display any signs of wear and tear, such as torn upper material, wrinkles, or holes?
The soles of shoes gradually erode and overpronators may observe a distinct incline in the wear of their soles.
The moment you finish a run, your feet begin to ache, especially the arches, as your shoes lose their ability to provide the necessary support.
New blisters emerge as your shoes undergo a transformation, signaling the need for a fresh set.
When discomfort arises in the knees, hips, or lower back, it may be a sign that the shoes are affecting your stride and body alignment. One telltale sign of diminishing shoe cushioning is the onset of more aches, signaling the impending need for a fresh pair of shoes.
According to your schedule, it is crucial for long-distance runners to take note of the day they purchase new shoes. Additionally, it is recommended to set a reminder after covering around 300 miles to assess the comfort of your shoes. Subsequently, it is advisable to repeat this evaluation every 50-100 miles.