Altra Duo

Altra Duo 

If you're looking for a super lightweight, max cushioned shoe for your longer distance speed work outs then this is it. It's got maximum toe volume to maintain the natural toe box feel, and a strong dosage of cushioning so you can really get that comfort and protection on your longer runs. 

The Duo does come in a very lightweight construction and therefore the upper is designed for lower levels of usage. For runners it's idea in a rotation with other shoes.