Best running shoes? No fast answer, experts say

If the return of cooler weather across the nation motivates you to begin running or to pick up where you left off, your first step might be to invest in new shoes.The choice now can be bewildering with all the lightweight, flexible shoes flooding the stores and posing a stark contrast to the traditional, heavily cushioned, rigid ones.

Running shoes fuel annual sales of more than $5 billion. A good pair costs you $100 to $140 whether stiff or flexible. Take your time deciding, medical experts and researchers say, or you could be dealing with an injury that becomes chronic or takes months to heal.

The new generation of lighter shoes has minimal cushioning across the bottom. The shoes are flexible front to back and side to side and have lower heels. Their design springs from the barefoot running craze and is based on a technology for runners who are midsole or forefoot strikers, meaning they strike first with that part of their foot. This style of running became trendy after Christopher McDougall's wildly popular 2009 book, Born to Run, about Tarahumara Indians who run 150-miles plus at a time in Mexican canyons, where they live,
with only the lightest of support on their feet. McDougall, who had many injuries as a "shod'' runner, embraced barefoot running.

Traditional shoes are mostly for heel-to-toe strikers, dating back to the early 1970s when the first waffles started appearing on the bottom. Gradually more and more cushioning and support were added, first under the heel and then into the mid and front part of the shoe to protect the foot from impact. They developed along with the jogging craze.

"There are people who are really pushing the minimalist shoe," says Steve Messier, director of the Wake Forest University Runners' Clinic. "But anyone who starts to talk about this shoe is better than that shoe is speculating. The point is we don't really know yet which kind of shoe is better. There's not enough science yet to support it."

Research published in the journal Nature in 2010 found people who run barefoot produce fewer pounds of force when their feet hit the ground compared with shod runners. Lead researcher Daniel Lieberman, professor of human evolutionary biology at Harvard in Cambridge, Mass., wrote "forefootand midfoot gaits were probably more common when humans ran barefoot or in minimal shoes, and may protect the feet and lower limbs from impact-related injuries experienced by a high percentage of runners."

The main goal of any runner, Messier says, is to stay injury free.

"They love running and don't want to have to stop,'' he says. "We hear about it when they do have to stop for any reason. Nothing else can replace their running, they tell us. We understand them."

When it comes to buying new shoes he says, "the first question I ask people is why switch to a different style? Is it because it's trendy? If it's not broken why fix it? We're confident running improves quality of life and we like to see people run into their 80s or 90s.''

Irene Davis says she is confident barefoot running strengthens your feet and improves your running. Nicknamed the "Barefoot Running Professor," she is director of the Spaulding National Running Center at Harvard.

She notes about 80% of runners get injured in any year. "So it's not like (traditional) shoes are really preventing injuries," she says.

The key problem with traditional shoes, she says, is a cushioned heel promotes a rear foot strike that is associated with greater impact loads. It also stiffens the leg, she says, and doesn't allow the leg to better support the body's weight. This stiffness is possibly what has led to some of the most common runner injuries (shin, knee and hip problems).

Running barefoot or in a minimalist shoe strengthens the foot and allows it to carry load, she says, but adds "you need to take it slow when you're getting started."

When forefoot striking, runners switch to run a shorter stride (take a long stride and you'll land on your heel; that hurts when barefoot or in a minimal shoe.) She says they retrain people at the running center how to stride when making the transition.

How to tell if a shoe is designed for fore foot striking? She says if you can't easily twist and bend the shoe than it is too stiff.

But pay attention. Here's where the debate continues. Naomi Shields, an orthopedic surgeon and spokesperson for the American Academy of Orthopedic Surgeons, says if she can take a shoe and twist the toe back to the heel, then it does not have enough support.

"I can tell you I've been seeing so much tendinitis and stress fractures in feet that have taken people out of running because they're wearing these lightweight shoes,'' she says."It used to be flip-flops sending people to me, now it's these."

But serious runners might have other reasons to switch: They want to pick up speed and think the shorter stride and lighter shoes help. Is that necessary for weekend warriors?

Shields says if people run or jog 8- to- 11 minute miles, then more than likely they're heel-to-toe runners and need a supportive shoe. "You're not going to pick up much speed if you were to switch anyway," she says.

Messier says unless you're an elite male athlete (2 hours, 30 minute marathon)or elite female athlete (2 hours, 50 minute marathon), why rush to change?

"My recommendation would be to wait until the research is out," Messier says. "The important thing is you're able to run for the rest of your life. Running improves so many parts of your life from a physical standpoint to an emotional standpoint."

Davis,who runs barefoot about 12 miles total a week because "it's the most natural way to run," says if you're starting out barefoot or wearing a minimalist shoe take it slowly.

"We've deconditioned our feet in cushioned shoes,'' Davis says. "They move us away from moving the way we're supposed to run. We can recondition our feet."

But slow and easy, she warns. "My recommendation the first time is three minutes. And then build up to running longer. We have to be careful until we have more data, but we're working on finishing some new research now."