But Abboud is already delivering the punch line: No matter how he looks at them, high-priced running shoes aren't better than lower-priced models within the same brand.
"What we found is really astonishing," he says. "We are going deeper and deeper to find why we are paying more for some shoes. At the moment, we cannot find a reason except for better material on the outside. Nothing on the inside of the expensive shoe is better."
(Do you buy expensive athletic shoes? Tell us why or why not on WebMD's Exercise & Fitness: Rich Weil, MEd, CDE, message board.)
How to Choose a Running Shoe
It's always a bad idea to buy a running shoe based on price. Instead, you should buy it based on comfort, says Charles F. Peebles, DPM, of the Atlanta Foot and Ankle Center.
Have an experienced running-shoe salesperson look at the arch of your foot while you're standing. If you have a high arch, you'll need a shoe that's curved across the bottom (the "last" of the shoe). If you have low arches, you'll need a shoe with a straight or slightly curved last. People with low arches may also need custom-made shoe inserts and/or arch supports.
Running is a high-impact activity. First and foremost, running shoes are designed to lessen that impact. This means the shoe should be the proper size. Abboud and colleagues found that the size printed on the shoe is not necessarily the shoe's true size. So when shopping, always try the shoe on. There should be one-quarter of an inch between your longest toe and the tip of the shoe.
Since your feet swell as the day goes on, try on shoes at the time of day you usually go for a run. And be sure to wear the same kind of socks, orthotic devices, or braces you wear when running.
Your feet bend only at the toes -- so make sure that's where the shoe bends, too. Try bending the shoe in half. If it folds in the middle or near the heel, Peebles advises, don't buy it.