by Jacob Greski
Since the inception of modern running shoes roughly a century ago, they have drastically evolved into the shoes we recognize today. When Roger Bannister broke the four-minute mile in 1956, he was wearing a pair of oxfords with nails driven through the sole. Over the past sixty years, shoes have evolved into the most technologically advanced piece of clothing you will ever wear. Trends have come and gone over the years in an effort to accomplish two things: to appeal to current consumer trends, and to make the overall running experience more enjoyable. An example of one trend would be barefoot or minimalist running shoes, which took place about a decade ago. These thin and flexible shoes often had 5 “fingers” for each of your toes and were without any support or cushion. The idea of less is more with running shoes started to become popular during this time. This trend, however, quickly backfired, as transitioning from a cushioned and supportive shoe to going nearly barefoot caused a plethora of injuries. This actually resulted in one of the leading barefoot running companies, Vibram, to be sued for their claims that their barefoot shoes reduced injuries, when the exact opposite had occurred.
I have previously written a Pace Setter article on the topic of cushioning (Cushioned Shoes: Is More Better?) discussing the impact of more or less cushioning on running injuries. Looked at over many decades, shoes have gotten increasingly thicker soles. What is considered today as a minimally cushioned shoe today would be considered a very highly cushioned shoe twenty years ago. This extra cushion is enjoyed by runners of various ages and speeds, with all major brands developing highly-cushioned models. Rather unexpectedly, they are also becoming lighter, thanks to advancing cushioning technology and materials science. It’s not uncommon for a new model to be released that is a few millimeters thicker yet a half or full ounce lighter in weight. Along with this thick sole comes extra softness, as many describe a new running shoe as “walking on a cloud”. Twenty years ago this idea of walking or running on shoes that were marshmallow-soft would be absurd, yet today many cannot go a mile without that plush feeling.
A New Genre of Road Racing Shoes
Nearly three years ago World Athletics, the governing body of professional running, placed a limit on how thick a shoe’s sole can be in order to compete in an official road race. The limit was 40 millimeters, or over 1.5 inches at the heel of the shoe. This is why today nearly every high performance road racing shoe has a heel thickness of 39.5mm, a half a millimeter under the legal limit. To put that into perspective, that’s less than the thickness of a credit card! This shows the clear benefit for more cushioning when it comes to racing, and runners worldwide are lacing up these thick-soled “super shoes” for any distance.
Another drastic change to road racing shoes is the addition of carbon fiber. The first racing shoe of this type, the Nike Vaporfly 4%, had a carbon fiber plate along the length of the shoe, which was found to greatly improve running economy. The addition of carbon fiber can be found in any high-cushion road racing shoe today.
More Foam but Less Rubber
With the addition of soft and squishy foam comes the removal of outsole rubber on the bottom of the shoe. Several brands have shaved off rubber over the years, whereas it used to be common to see outsoles with much more rubber. While this does lighten the shoe, it also provides less midsole protection and leads to quicker breakdown. This tradeoff is a trend that many runners are willing to make in order to feel good in a lighter shoe. Others are frustrated (and rightly so) that their expensive running shoe did not last as long as they had hoped. Advancements in the type of rubber used are also becoming commonplace, creating lightweight, durable and high traction rubber that still can handle many miles. One shoe from Adidas, the Adidas Adizero Pro 3, uses a continental rubber along with a rubber that is actually used in rock climbing shoes. Despite this shoe’s thin outsole layer, there is plenty of traction even in wet conditions. Another shoe, the Saucony Peregrine Ice, uses an outsole material that’s designed to provide traction on ice. From personal experience I can confirm it's surprisingly effective on the smoothest ice. It really is remarkable how far this outsole technology has developed even over the past ten years.
Running in Rocking Shoes
One of the most recent running shoe trends is the implementation of a rocker. A rocker is an upward curling of the front of the shoe, giving it a forward rocking sensation. This is common in those highly cushioned road racing shoes previously mentioned and others designed for faster running. The purpose of a rocker is to put the runner or walker more on their toes and transition them through their gait quicker. The amount of rocking that one feels can vary, as this is dependent on their running or walking gait. If someone is a heel striker, likely the rocker will be much more noticeable than someone who already runs on their toes. Some shoes are designed to rock more or less, depending on what kind of running they are designed for. The severity of each rocker can also differ by brand, so if you’re trying out shoes with a rocker its important to test a variety of brands.
Jake has kindly agreed to be a frequent contributor to The Pace Setter. His background as an elite runner, running shoe specialist, and student in the Doctor of Physical Therapy program at Russell Sage College, makes him uniquely qualified to write columns that our readers will benefit from greatly.
Thanks, Jake for coming onboard.