The Inside-Out of a Running Shoe
Often when shopping for footwear, you will hear a salesperson use high-tech words to describe the particular features and parts of the running shoe. With a little basic knowledge of running shoes, you can become a more informed buyer and satisfied user. This shoe anatomy session can help you buy the shoe that's right for you.
The toebox refers to the toe section of the shoe. It should be roomy enough to comfortably fit your toes. There should be approximately half an inch between your longest toe and the end of the shoe, and half an inch between the top of your longest toe and the top of the toebox.
Next, take a look at shoe laces. You should use laces that are not too long or too slippery. If they are too long, cut them down or use lace locks.
Held together by the laces is the upper, or the material that encloses the foot. Breathable fabrics such as mesh keep feet from overheating in the summer. When choosing a shoe, be sure the upper fits properly; it helps the shoe stabilize the foot.
Beneath the laces you will find the tongue of the shoe. The tongue should be thick enough to protect the top of the foot from the pressure of the laces, but not so long that it rubs against your foot just above the ankle.
Occasionally, runners complain about their feet feeling tingly or numb, particularly during longer training runs. This is sometimes attributed to shoelaces being tied too tightly, which reduces the circulation of blood to one's feet. A simple solution for this annoying problem is to tie your laces just tightly enough that your shoes stay snugly on your feet. Another option that may help is to change the lacing pattern of your shoes.
At the back of the shoe is the heel notch, the slight depression cut into the shoe's heel collar to reduce Achilles tendon irritation and provide a more secure heel fit. The heel counter is the rounded place where your heel fits snugly yet comfortably. Too loose a fit can cause blisters on your heels.
If you need extra stability (for instance, your feet wobble a lot), look for a stiff heel counter or an external heel counter (a ring that wraps around the outside of the heel). On the bottom of the shoe, look for the split heel, a two-part heel structure that separates the outer and inner sides and contributes to a smoother heel-to-toe transition.
Look for heel heights that match your cushioning needs. If you are a big person, chances are you are more of a heel-striker and want more midsole foam under the heel, so you need a greater heel height. Faster runners tend to strike more in the midfoot and need a lower heel.
Getting to Know Your Soles
Most of the cushioning and shock absorption in shoes is provided by the midsole, the part of the shoe that you can't see (located above the outer sole). You will want one of two midsole foams: polyurethane or EVA (ethylene vinyl acetate). Polyurethane is denser, heavier, and more durable than EVA. EVA is a softer, cushier material. Generally, heavier runners do well with polyurethane midsoles. EVA is more common because of its lightness and more cushioned feel.
The material that covers the bottom of the shoe is referred to as the outer sole. You will want one of three kinds of outer sole: carbon rubber, blown rubber, or a combination of the two. Carbon rubber is more durable but heavier and stiffer than blown rubber. Some shoes have carbon rubber in the high-wear areas of the rear foot and the cushier blown rubber in the forefoot for a softer feel.
Running shoes also contain stabilizing technology, or devices that reduce overpronation or excessive supination (also called underpronation). These devices are usually in the shoe's midsole on the arch side of the shoe. Some shoes have firmer densities of midsole foam to combat overpronation.