EVA foam midsoles are relatively cheap and light, but the cushion typically wears out after about 400 milesmuch sooner than the rest of a shoe. The alternative? Innovative springs, gel pods, and air pockets, which may cost a little more in the short term but promise longer life down the road.
Repeat after us: I will not go grocery shopping in my running shoes. Extend the life of the midsoleswhatever they're made fromby using shoes for running, not walking.
Almost all shoes today are light enough, so don't sweat an ounce or two to get the fit and performance you need. Just avoid anything over about 14 ounces per shoe (for a men's size 9) or you'll feel like you're running in boots.
New to runningor simply never found the right shoe? Get help from a specialty dealer. Your particular foot shape and gait will work better with some shoes than others, and a shop with expert fitters, a wallful of models, and a treadmill for wear testing will help you zero in on the perfect kicks.