A high school cross country runner recently told me about these “amazing” new running shoes he had just purchased for the season. According to him, all the best racers were wearing shoes with this new technology which helped you run faster. The shoes had a carbon plate in them and he did feel faster running in them, but he started questioning whether he should run in these fancy new shoes everyday or if they were just for racing? Were carbon-plated shoes going to cause an injury? These are great questions if you are a competitive runner, enjoy running in local 5Ks or like to jog around your neighborhood for exercise.
In 2018, runners wearing the Nike Vaporfly shattered world records in nearly every long distance event. In 2019, Eliud Kipchoge wearing Nike Air Zoom Alphafly Next% running shoes became the first person in history to run a marathon in less than 2 hours. Nike boasts that regardless of your skill level, this new generation of running shoes can improve running economy by 4 percent. In this blog, we are going to take a look at how these shoes work, discuss any drawbacks to this new technology and make recommendations for running in the shoes safely.
There are four components to these shoes that could improve running speed; however, researchers still haven’t figured out exactly which components are responsible for the improved running times. The first component is a graphite plate in the midsole of the shoe that works like a diving board to help propel you forward. It does seem like this would give a little more bounce to your step and therefore, increase your speed. However, recent research has shown that the carbon plates do not act as springs and they play little role in improving running economy. A potential downside of carbon plates is that they increase your stride length which could result in hamstring or Achilles injuries. If you decide to wear these shoes it would be important to strengthen your hamstrings and hip flexor muscles to help prevent injury.
The second change in running shoe production has been the addition of toe springs. Toe springs have been added into almost all modern running shoes to improve comfort. Although, toe springs make shoes more comfortable they may contribute to the weakening of small muscles in the feet. This can increase your risk of developing plantar fasciitis. Runners who wear shoes with exaggerated toe springs should incorporate arch and toe strengthening exercises into their training program. It is also recommended that athletes should race in their super shoes but train in running shoes that allow their toes to bend.
The third feature of the modern super shoes is a state-of-the-art midsole material that has been designed to store and return energy. The ideal material functions like a pogo stick. Research has confirmed the vast majority of energy returned while wearing the Nike Vaporflys comes from the midsole material, not the graphite plates. The possible downside to this midsole is that it also slightly increases a runner’s stride length and impact forces which could lead to injuries. To take advantage of the slight increase in performance associated with these shoes it would be important to include hamstring and calf flexibility and strengthening exercises in your training program.
The final component added to the new generation of shoes is an extra-thick midsole. Apparently, the running shoe industry decided to make the lower legs of runners longer by increasing the height of the midsole. The theory is that with longer legs a runner will be more efficient and faster. World Athletics recently banned shoes with a midsole thickness greater than 40 mm, because of the perceived advantage associated with thicker midsoles. In June of 2023, researchers from the Human Performance Lab proved the ban on running shoes with thick midsoles was unjustified. Their research study found that thick midsoles had no effect on running performance and they may actually cause your foot to rotate inward (pronate) more when running which could lead to a wide range of running injuries. If you have flat feet and are considering shoes with a thick midsole you should strengthen the muscles in your toes and the arch of your foot to help control excessive rolling or pronation of your feet while running.
The bottom line is YES: the new generation of super shoes can produce slight increases in running performance! However, these improvements come at a cost. To take advantage of the benefits of these shoes, it is important to incorporate an exercise program to improve flexibility and strength of the hamstrings, hip flexors, calves, arches of the feet and toes.
On the flip side, a runner should keep in mind that regardless of the shoes worn, the vast majority of strength and speed comes from our own muscles and tendons. It is possible for runners of all levels to significantly increase performance and reduce injury by improving the ability of their own tendons to store and return energy. Any gains made by a running shoe are only temporary, but we do have the ability to make our tendons stronger and more resilient to improve both running and overall health!
On an anecdotal note, the cross country runner discussed above decided to train 1-2 days a week in his carbon plated shoes and rotate in other running shoes 3-4 days a week. He reports feeling an increase in speed and energy return in his “super shoes”.
Please contact Dr. Iodice at Advanced Healthcare & Sports Injury for help incorporating the correct flexibility and strengthening exercises into your running program. Happy Running!!
