Midsoles – EVA Versus PU
- May 4, 2017
- Posted by: marlenedubois
- Category: CPR Training
When deciding which running shoe to buy, perhaps the most important feature of the shoe will be its midsole. You can’t see the midsole (the item will be sandwiched between the outsole as well as the insole), however the item will be largely responsible for the cushioning your feet, knees, hips as well as entire body receive each time your feet hit the ground. the item can also help promote foot stability as well as prevent conditions such as over pronation (when your foot rolls too far inward) or under pronation (when your foot does not roll inward enough), which are associated with flat feet as well as high arches.
Midsoles are generally made coming from two basic materials: EVA as well as PU.
EVA stands for ethylene vinyl acetate. the item will be not plastic or rubber however foam. Each midsole will be made up of thousands of foam bubbles in which act like cells. Each one of these foam bubbles will be filled with gas. The result will be a material in which will be lightweight as well as flexible. Each time you land on an EVA midsole, your shoe breathes a little. The gas will be pushed out as well as then let back in once your foot leaves the ground.
PU will be also a type of foam. the item stands for polyurethane. The material will be heavier than EVA as well as will be generally less preferred by runners because of its density. in which said, PU tends to hold up better than EVA. Over time, the bubbles in which make EVA midsoles so light as well as bouncy to begin with permanently lose some of their air. PU gives less bounce from the beginning, however its bounce lasts longer.
Some midsoles are made that has a combination of the two midsoles. The classic design will be to put PU on the outside (where the shoe receives the most stress) as well as then maintain an EVA core.
In addition to the midsole, you will want to carefully examine the shoes’ various other features as well. With regards to the outsole, the item will be normally most important to examine the quality of traction the item provides. Features to look for with insoles include arch support as well as contoured foot beds.
A word to the wise: often Shoe companies will use special terms or “company lingo” when the item comes time to advertise these straightforward terms. For example, Asic’s Speva(TM) will be in fact a fancy way of saying EVA (i.e., spEVA). Most high quality running shoes favor EVA over PU, or some combination of the two. You probably will not find too many PU-only midsoles, unless you are shopping from the vintage section.