How running in maximal shoes can affect your 5K time and potentially cause injury

The supposed benefits of a larger, more cushioned shoe have been championed for many years in the ultra running scene, heavily influencing current running shoe design and even impacting Nike's breaking2 project, leading to them producing a highly cushioned marathon race shoe in the Vaporfly Elite/4%, but all these shoes have been created with marathon plus distances in mind yet their popularity has seen them used in all disciplines and distances. 

So, can running in a such a shoe beyond its initial purpose cause issues for runners? One recent study believes so. 

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The Orthopaedic Journal of Sports Medicine conducted a study looking into the influence of maximal running shoes on biomechanics before and after a 5K run. Fifteen female runners aged between 25-51 participated in two testing sessions; one neutral shoe session in a New Balance 880 and one maximal shoe session in a Hoka One One Bondi 4, with 7 to 10 days between sessions.

Height and mass were measured prior to testing, with each runner having markers placed all over their bodies to measure running mechanics and kinematic data, with a force plate being used to measure kinectic data. 

Following five running trials to measure the data, runners were instructed to run 5K at their 5K pace on a treadmill, then repeat the same trials post-run. What the results showed was that runners exhibited increased impact forces and loading rate when running in a maximal versus neutral shoe.

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Why is this significant? 

Runners who were classified as heel-strikers exhibited increased impact forces and loading rate when running in a maximal shoe compared with a traditional neutral shoe. Because increases in these variables have been associated with an increased risk of running-related injuries, runners who are new to running in a maximal shoe may be at an increased risk of injury. Therefore, runners should consider this potential increased risk for injury when switching from a neutral shoe to a maximal shoe.

It's worth noting that further work is necessary to better understand the longer term impact of this type of footwear, yet these initial findings are of great interest as running shoes seem to get bigger and bigger. 

Read more of the study here