If the running shoe fits.

If you feel mystified by the huge selection and the dozens of variables that running shoes can claim, you might walk out of the store with a pair of shoes but without any confidence that you have picked the right shoe for your needs. Maybe you've been lucky, have great biomechanics, have run thousands of miles without any injuries, and just buy the same basic shoe over and over again. But for lots of runners, buying a shoe is more complicated than that. It can mean the difference between running healthy for years or being deviled by injuries. Your first, and probably most important step should be to look for a running shoe specialty store rather than a store that sells a variety of athletic shoes. A running store is usually owned and operated by an expert who has run the roads for years and has the knowledge necessary to give you expert guidance.

More than half of all runners either overpronate (feet roll too far to the inside and push off the inside edge of the forefoot) or underpronate (feet don't roll in quickly enough so each stride finishes on the outer edge of the foot, near the little toe). To find out if you do, wet your bare feet and step on a piece of cardboard. If you can see the entire sole in the imprint, you probably have a low arch and tend to overpronate. If you see only portions of your forefoot and heel with a narrow connection between them, you probably have a high arch and tend to underpronate.

The bottoms of your well-worn running shoes can provide clues as to what your foot does during your stride. Overpronation can create extra wear on the outside heel and inside forefoot; underpronation causes wear on the outer edge of the heel and the little toe. A podiatrist, orthopedic foot and anide specialist, or sports medicine specialist can analyze your foot mechanics and prescribe shoes and orthotics to alleviate problems, especially if you have suffered unexplained or recurring injuries.

RELATED ARTICLE: FORM EQUALS FUNCTION

If you wear a shoe that's inappropriate for the activity you're engaged in, you risk injury. Look for a sport-specific shoe. A running shoe should provide excellent heel cushioning and shock absorption, a flexible forefoot and a distinct Achilles notch. A walking 4 shoe is more rigid than a running shoe, with a rounded sole so you can smoothly shift weight from heel to toes. While running and walking shoes assist you in moving front to back, crosstrainers, basketball, aerobics, and tennis shoes control side to side movements. Don't play tennis in a running shoe, you'll twist your anlde. Save your running shoes for running and vice versa.

RACING FLATS 

Extremely lightweight and used by competitive runners. For short distances, a biomechanically inefficient runner can get away with using flats. A biomechanically efficient, young runner can use racing flats for all needs. But for everyone else, racing flats increase the risk of injury.

SPIKES

Generally spikes are for sprinters. Some spikes are intended for longer distances but they are strictly track shoes.

LIGHTWEIGHT TRAINERS

These have a little bit more cushioning and a bit more support than racing flats. Its design is the lightest possible and is for a biomechanically efficient runner for long distances or for the less efficient runner racing shorter distances. Some runners choose to train in a neutral or mild stability shoe and race a short course in a lightweight trainer.

STABILITY SHOE

These control pronation with stability and very little cushioning.

MOTION CONTROL SHOE

These provide complete stability with virtually no cushioning, controlling the extreme pronator.

TRAIL SHOE

These have a bottom that is largely used for increased traction and are generally moderately stable.

No matter how perfectly a shoe fits both form and function, it won't stay that, way forever. Your shoes can look okay but no longer provide proper support or shock absorption. Throw out your old favorites after 300 to 500 miles of running. If you suffer recurring injuries you may need to replace your running shoes even more often. Replace insoles frequently (they can wear out before the whole shoe does). Get a few pairs and rotate them. Mark each pair with the date purchased to help you keep track of their age and mileage. Think they'll ever sell them with a built-in odometer?

SHOE PARTICULARS--WHAT'S UP'

SHAPE

Match your foot shape to the shoe. Each company makes its shoes around its own set of "lasts" or foot-shaped molds. They vary in arch height, heel width, toe box size, etc. One manufacturer's shoes may generally fit you better than another.

CUSHIONING

Shoe cushioning distributes ground reaction forces as your feet hit the running surface. Adequate cushioning in the midsole is especially important if you over- or underpronate, if you are an older runner, weigh more than your ideal weight, or have arthritic foot and toe joints.

STABILITY

The shoe's heel counter (the part that cups the heels) should be firm and sturdy. If it "gives" too much, side to side, look for a better shoe. In general, overpronators need more stable shoes than underpronators do. So, if you overpronate, be especially careful to select a shoe with a stiff heel counter and rear upper (the part that covers the top of the foot near the ankle).

FLEXIBILITY

Underpronators generally need more flexibility in their shoes than overpronators do. To determine the flexibility of a shoe, hold it by its heel and midfoot (not the toe) and twist--the more a shoe resists, the stiffer it is.

FIT

Have both of your feet measured, even if you think you know your size. Feet widen and lengthen as you age or gain weight. Even when you've confirmed your size, remember fit is what matters. Sizing standards can vary from one manufacturer to another--ignore the numbers and get the fit right. You can have as much as a thumb's width to spare in front of your longest toe so that your toes don't get jammed on downhills. Look for a roomy toe box with enough space across the widest part of your foot. The fit, however, should be snug at the heel and midfoot to prevent slippage during movement.

CONSTRUCTION

For all shoes, make sure that the central heel line is fully vertical and not tilted in or outward due to manufacturing defects. Set the shoes on a flat surface at eye-level. A vertical line drawn down the center of the heel should be exactly at right angles to the bottom surface of the heel as it sits flat on a counter. There should be no tilt or rock side to side. Check to see that the shoes' seams are glued securely by tugging on the shoe while holding the sole. You shouldn't detect any give at all. Check to see that gel or air pockets are inflated evenly and resist collapsing under pressure.

TIPS on BUYing Running Shoes

from THE American Academy of Orthopaedic Surgeons

* Try on running shoes after a workout or a run, and late in the day. Your feet will be at their largest.

* Wear the same type of sock that you will wear for training.

* You should be able to freely wiggle all of your toes when the shoe is on.

* The shoes should be comfortable as soon as you try them on. There should be no break-in period.

* Run a few steps in your shoes. A good running shoe store will even let you run back and forth in front of the store.

* Always relace the shoes you are trying on. You should begin at the farthest eyelets and apply even pressure as you criss-cross to the top of the shoe.

* Your heel should not slip as you run. It should be snug at the midfoot to hold the shoe in place between the tongue and the sole.

The American Running Association Editorial Board Member Bruce Wilk, P.T., O.C.S. contributed to this article. Portions were adapted from IDEA, The Health and Fitness Source, April 3, 2000 News Release. For the real low-down on shoes, consult The American Running Association's Running Shoe Database at www.americanrunning.org and check out "shoes and apparel" under the Fitness Articles section.