Real Adidas items are uniformly and neatly stitched. Fake ones will have shoddy and loose stitch work. Uneven stitching often makes it easy to spot a fake Adidas product.

Nike's running shoes generally run narrower than Adidas's, most notably in the heel and midfoot. This can provide some added support for your ankles if you're a fan of it, but it can also disrupt the way some people's feet naturally roll through a strike.

Adidas sizing is generally true to size. The label themselves advise that for a more loose feel, you should go up a size or, for a more snug fit, try a size smaller. These are, after all, relaxed sports-oriented pieces that need to fit your particular lifestyle.