
Photograph by Whitney Curtis
You wouldn’t expect to hear about physics when walking into a shoe store. Then again, most shoe stores aren’t owned by a former NASA engineer.
But for Fleet Feet’s David Spetnagel, science is ingrained in the running store’s philosophy. “Everything is based on physics,” says the enthusiastic owner of three local franchise stores (fleetfeetstl.com) and former Lindenwood University running coach. “Ninety-seven percent of running injuries are due to overloading the body or over-rotation. Our goal is that for every pound the shoe absorbs, or any degree of unwanted rotation that’s avoided, it’s going to reduce your chances of injury.”
His solution: finding the perfect fit.
Combining his engineering background with wear-testing for Running Times Magazine, he developed proprietary software that literally matches each customer’s feet to the ideal pair of shoes. “We’ve got so much data over the years that we’ve really dialed into the process,” he says.
From the store’s selection of nearly 50 men’s and 50 women’s styles, Spetnagel believes just a handful are right for a given customer. The trick is narrowing it down. “If a fitter wants to do a good job, they’d have to remember about 1,400 data points about the shoes at any given time,” he says. “So we’ve catalogued all of our shoes and match them to 13 characteristics of the runner.” These traits include foot shape, gait style, and typical running terrain, not to mention myriad other considerations. After a 15-minute fitting (ruler and all), a PDA spits out a list of recommended shoes with compatibility scores, sort of like a dating website—if only dating were so easy.
In finding the right pair, Spetnagel suggests focusing on three running-shoe categories: 1) road, 2) trail, and 3) racing. The labels are apt, he says, so consider the purpose. And once you’ve found your fit, consider that a typical runner’s shoes absorb hundreds of pounds of impact load with each stride; six months later, they’ve lost about 70 percent of their cushioning. “If you can feel the indentations of your toes in the balls of your shoes,” says Spetnagel, “it’s probably time for a new pair.”
Going the Distance
Three surefire shoe-fitting tips
- Don’t run with the crowd. “The last reason to buy a shoe is it worked for your buddy. The chances of it matching all of your feet’s characteristics are very low.”
- Spill your guts. “Don’t be shy about showing your feet… We need to be able to see those black toenails, calluses, or bunions.”
- Don’t run shoes ragged. “You’ll get the same amount of life out of two pairs of shoes by alternating between a fresh pair and dead pair as wearing three pairs back-to-back.”
Did You Know…
The average performance running shoe has about 50 parts.