Midsoles – EVA Versus PUadmin
When determining which running shoe to buy, perhaps the most important feature of the shoe is its middle sole. You can not see the middle sole (it is between the outsole and the insole), but it is largely responsible for kissing your feet, knees, hips and whole body every time your feet touch the ground. It can also help to promote foot stability and prevent conditions such as overprotection (if your foot goes too far) or under pronation (if your foot does not walk in), which are associated with flat feet and high arches.
Midsoles are generally made of two basic materials: EVA and PU.
EVA stands for ethylene vinyl acetate. It's not plastic or rubber but foam. Each middle sole consists of thousands of foam bubbles that act as cells. Each of these foam cells is filled with gas. The result is a material that is light and flexible. Every time you land on an EVA soles, your shoe breathes a little. The gas is pushed out and pressed again as soon as your foot leaves the ground.
PU is also a kind of foam. It stands for polyurethane. The material is heavier than EVA and is usually less preferred by runners because of its density. Having said that, PU tends to keep better than EVA. Over time, the bubbles making EVA midsoles become so light and jumping to begin losing some of their air. PU initially reduces kickback, but stopping is longer.
Some midsoles are made with a combination of the two midsoles. The classic design is to place PU on the outside (where the shoe gets the most stress) and then maintain an EVA core.
Next to the middle sole you want the other features of the shoes as well. With regard to the outsole, it is usually important to investigate the quality of the traction it provides. Features for searching with insoles include arch support and covered footbeds.
A word in the way: often shoe companies will use special terms or & # 39; business loans & # 39; When it's time to advertise these simple terms. For example, Asic's Speva (TM) is actually a great way to say EVA (ie spEVA). Most high quality running shoes prefer EVA over PU, or a combination of the two. You may not find too many PU-only midsoles unless you shop in the vintage section.