When it comes to running injuries, a common belief is that older, worn-out shoes might be to blame. While this idea seems logical, studies suggest that the relationship between running shoe age and injury is far more complex than it appears. I love a new pair of running shoes as much as the next runner but should I expect to reduce my injury risk by replacing them? Let’s take a look at the evidence.
Does Shoe Age Really Matter?
It’s widely believed that worn-out shoes lose their cushioning and support, increasing the risk of injuries. However, studies provide a more nuanced perspective:
Plantar Pressure in New Shoes: Surprisingly, plantar pressure is often higher in new shoes, likely due to their reduced flexibility. This may increase the risk of injuries to the foot and ankle. The decreased flexibility of new shoes therefore may actually contribute to injury risk (Rethman and Makwana, 2011).
Men Vs Women:
Sex differences appear to exist in this study by Taunton et al. (2003). For men, running in shoes that are 4–6 months old seems to reduce injury risks however newer shoes (1-3 months old) provided the same effect for women. Meanwhile, women running in 4-6 month old shoes experienced more injuries overall.
These findings highlight the complexity of running shoe age and injury risk, particularly between males and females. Different foot posture, biological differences and shoe technologies may all explain the differences between males and females shown in this study.
Mileage and Wear: A Closer Look
Shoes degrade over time, and their performance may change based on mileage. After 200 miles (322 km), running patterns shift, with increased stance time compensating for reduced cushioning. (Chambon et al., 2014). By 480 km, the heel region’s cushioning diminishes by 16–33%, especially for rearfoot strikers. Interestingly, when runners are blinded to the shoes they’re wearing, they can’t identify these changes, even in trainers which have completed over 640km (Cornwall and McPoil, 2017).
What About Comfort?
Research suggests comfort is one of the most critical factors in injury prevention. Comfortable shoes reduce muscle fatigue and may lower the risk of injuries. (Nigg, 2016). Uncomfortable shoes can lead to compensatory gait patterns, increasing injury risk. (Asplund and Brown, 2016).
When trying on new shoes, there should be no ‘break-in period’. Shoes should feel comfortable as soon as you put them on for the first time.
Replacing Your Running Shoes: Expert Opinions
Clinicians often recommend replacing running shoes after 350–600 miles or every six months. However, evidence shows variability in how shoes wear down and their effects on runners. For example, new shoes may offer better shock absorption but could also contribute to injuries if overly stiff or uncomfortable. Old shoes, while degraded, might not always be harmful if they remain comfortable and suit your running style.
Intrinsic vs. Extrinsic Factors
Interestingly, runners themselves highlight unsuitable shoes as a major cause of injury alongside poor warm ups and excessive training (Saragiotto et al., 2014). In reality, running related injury is a multifactorial problem with various intrinsic and extrinsic factors.
OnTrack Takeaways:
I am going to attempt to simplify a very nuanced topic into some simple conclusions that you can implement right away.
Always replace your running shoes if they have serious structural damage which will affect the support provided by the shoe (like my torn 880’s above)
It should be love at first sight, or at least first wear! Choose shoes which are comfortable from the first wear, and if they are still comfortable after 200, 400, 600km or more then don’t change a winning formula.
Old running shoes DO NOT increase injury risk, in fact some studies showed regular changes in running shoes contributed to injury risk. Running shoes are a very personal thing, in fact, the only recommendation backed by science appears to be comfort!
Remember, this blog is relating to injury, not performance. Given that shoes mechanical properties can reduce over time, a newer pair of shoes may contribute to improved performance… but that’s a discussion for another day.
As always, if you have an injury it is advisable to be assessed by a health care professional. The advice on this blog should not be a replacement for professional medical advice.
At OnTrack Physio, we understand the unique needs of runners. Whether you’re dealing with an injury or looking for guidance, our team is here to help you stay active and injury-free.
Book a consultation today or get in touch to see if we can help you!
References used in this blog
Baur, H., Hoffmann, J., Reichmuth, A., Müller, S. and Mayer, F., 2012. Der Einfluss einer Schuheinlage aus Karbon auf die plantare Druckverteilung im Radschuh. Sportverletzung· Sportschaden, 26(01), pp.12-17.
Chambon, N., Sevrez, V., Ly, Q.H., Guéguen, N., Berton, E. and Rao, G., 2014. Aging of running shoes and its effect on mechanical and biomechanical variables: implications for runners. Journal of Sports Sciences, 32(11), pp.1013-1022.
Cornwall, M.W. and McPoil, T.G., 2017. Can runners perceive changes in heel cushioning as the shoe ages with increased mileage?. International journal of sports physical therapy, 12(4), p.616.
Saragiotto, B.T., Yamato, T.P. and Lopes, A.D., 2014. What do recreational runners think about risk factors for running injuries? A descriptive study of their beliefs and opinions. journal of orthopaedic & sports physical therapy, 44(10), pp.733-738.
Taunton, J.E., Ryan, M.B., Clement, D.B., McKenzie, D.C., Lloyd-Smith, D.R. and Zumbo, B.D., 2003. A prospective study of running injuries: the Vancouver Sun Run “In Training” clinics. British journal of sports medicine, 37(3), pp.239-244.
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