Evonik supplies VESTAMID®, an important high-performance material, for running shoes.
Who remembers James Fixx these days? At the end of the 1970s, the man was a celebrity, a star, because he started a mass movement. His book, The Complete Book of Running, made the United States into a nation of joggers, and it made him a rich man. His exercise bible stayed at the top of the New York Times bestseller list for months. The wave spilled over into other countries and no later than November 1978, when Der Spiegel magazine devoted its cover story to the trendy new sport, did Germany discover the pull of running as well.
People—infected with a desire to run—ran in fields, woods and meadows, on paths along rivers, on sidewalks, and if there weren’t any, in the street. On October 13, 1974, the first Berlin Marathon was run. There were 286 runners from four countries registered; 244 made it to the finish line. At that point, there was nothing to indicate that this was going to become the rage; people strolling in Berlin’s Grunewald forest used to make derogatory comments about the out-of-breath athletes running by.
Today, running has become one of the most popular sports ever: Whether New York, Paris, Tokyo or Berlin – it’s happening all over the world. Even on the Great Wall, thousands of enthusiasts run year after year. Runners literally go over hill and dale, and after a heavy rain, through mud and muck. Therefore, high stability and elasticity on the shoes material are required.
Running shoes with VESTAMID®—to put your feet in good hands
Running shoes must support the complex interaction of muscles, knees, and ligaments in the foot. This means they have to cushion hard shocks, stabilize the foot, and withstand high stress. The shape of the shoe and, above all, the material of the sole have a decisive impact on the welfare of the knee and Achilles tendon. In a 10 km race, for instance, each foot pounds the ground about 4,300 times, with a force equal to two to three times the weight of the body. Going downhill, the force is six times that weight. The sole material should prevent the functional and cushion elements from being compromised over time and becoming ineffective, and it should also keep its shape in extreme temperature fluctuations.
The shoes need to give a feeling of effortlessness—giving sprinters wings, and long-distance runners legs that float. Because the polyamide 12 molding compounds from Evonik have a density of just under one, the weight savings for a 100-meter sprinter would be one kilogram. In addition, the shoes need to be able to handle environmental influences. Top athletes need to perform at their best both at extremely low temperatures of down to -40°C and in extreme heat, so temperature fluctuations also need to taken into account.
The magic word is cushioning
Cushioning is supposed to keep the feet as comfortable as possible on hard surfaces without neglecting athletics, and while supporting the work of the muscles and joints. The sole system is what provides the cushioning, which, depending on the design, is usually divided into a topsole, mid-sole, and an outsole. Different combinations of materials are used for different types of stresses. A variety of VESTAMID® grades are utilized, mostly as mid-soles or outsoles, providing optimal cushioning.
The market is always changing, and new trends pop up all the time. The shoes the 244 marathon pioneers wore running through Berlin’s Grunewald in 1974 are now fit only for a sports museum. Training versus race shoes, cushioning, cutting-edge transparency and design, new requirement emerge every season practically—which means new challenges for manufacturers and their suppliers.
And Fixx, the man who got us all running? He died of a heart attack while out on a run at only age 52. But his notion of running as an ideal sport—because it was simple, healthy, and inexpensive—continues to fascinate millions of people around the globe.