When you're a child it's simple: Sneakers make you faster. If you're wearing athletic shoes, you'll outrun the guy in clunky, brown dress shoes. The reason, as any child can tell you, is because sneakers weigh less. Lighter shoes let your feet really fly. But there are several complex, grown-up reasons for this phenomenon that you should understand if you want to protect your body while running faster in less shoe.
According to famed running coach Jack Daniels, a runner expends 1 percent more aerobic energy for every 100 g of weight on a shoe. That seemingly slight difference is significant. A researcher at the Nike Research Laboratory calculated that shaving 4 oz. from a shoe would mean a faster marathon time by up to 3 minutes. By comparison, using the illegal, performance-enhancing drug EPO saves a marathoner just over 3 minutes.
The trend toward minimalist running shoes -- the so-called "barefoot" running revolution -- puts the role of shoe weight and speed in the spotlight. One shoe designed to mimic barefoot running weighs a scant 5.3 oz. A standard running shoe weighs more than 10 oz. It would seem that those who opt to run barefoot, or in radically reduced shoes such as racing flats, should be running faster than people who run with their feet atop the thick soles of motion-controlled shoes.
When it comes to shoes, cutting weight doesn't automatically mean shaving time. There comes a point when reducing material and weight on a shoe actually slows a runner down. Too little material underfoot reduces shock absorption and energy return. Less energy return means either reducing foot turnover or using more energy to run the same speed. That makes the runner less efficient. Over the long haul, a less efficient runner is a slower runner.
A shoe that provides optimum energy return, while not weighing an ounce more than is necessary, is the shoe that will allow you to run as fast as possible without breaking down. That happy medium is elusive, but available to both average and top-flight runners. Finding the perfectly weighted shoe that will help you reach your ultimate performance level, however, requires some research and patience.
To find the right lightweight shoe, consult a professional at a running shoe store or a podiatrist. You may be able to find a lighter version of the shoe you're already running in. Wear your lighter shoes one day out of five so your muscles and tendons adapt without injury. Add one day per week one week at a time. You may have to try several pairs of new, lightweight shoes before you find the right ones.