Check running shoes before buying new pair
Examine the soles of your old running shoes to determine the wear pattern before you buy a new style.
Q. How can I fit myself for new running shoes
A. First, are you sure you want a new pair
"If you're running injury-free, the worst thing you can do is buy a different shoe," says Robert Butler, a running-mechanics researcher at the University of Evansville.
Unless your body cautions otherwise, wait to replace your kicks until their breakdown point -- between 400 and 600 miles of use.
Then, when selecting a new pair, look to your old soles for direction. If the bottom of your shoe has worn down between the second and third toes (the big toe is number one), your running mechanics are normal, so stick with the type of shoe you have. Wear at the big toe shows that your foot pronates, or rolls inward on impact; a shoe with motion-control technology will help. If the fourth and fifth toes are worn, you underpronate -- you run on the outside edges of your feet. Buy an extra-cushioned shoe.
Cushioning
Look for a firm response in the heel, not a mushy or soggy feeling. Soft heel cushioning causes your foot to sink deep into the shoe, stressing your Achilles tendon.
Flex point
The ball of your foot should align with the shoe's widest zone. This zone contains notches that allow the shoe to flex. If the ball of your foot falls behind this zone, it'll cause your arch to bend instead of your toes when running and you'll strain your arches.
Removable insole
For a foolproof fit, take out the insole and step on it. You should have an index finger's width between your big toe and the insert's front end, says Dr. Douglas Richie, a former president of the American Academy of Podiatric Sports Medicine.
Toe box
Wide is better. A narrow box can blacken toenails. Neither your pinkie nor big toe should extend beyond the shoe's normal frame.
Back heel
Blood flow increases and ligaments swell while you're running, which can add a half size to your foot. Slip your index finger between your heel bone and the shoe's rear wall. If there's no wiggle room, the shoe is too small.
Arch support
The shoe's toe box should bend when pressed diagonally onto a hard surface. If the arch collapses first, it's an inferior shoe that'll strain your foot.