Both trainers have lateral crash pads to absorb shock during foot strikes. They have harder carbon rubber on the heel areas with softer, blown rubber on the forefoot and midfoot. In the Pegasus 39, the air bag is so large that it takes up the entire forefoot so you can’t feel the outline of it.īoth outsoles have plenty of thick, durable rubber. In the Structure 24, you can feel the outline of the air bag underfoot which feels slightly lumpy. Ride transitions are smoother in the Pegasus 39 than in the Structure 24 due to the air bag implementation. The Pegasus 39 is firmer than the Structure 24 but it still has a lower level of stability.

It has a built up medial-side which prevents over pronators from excessive inward rolling of the ankle as well as a midsole with a large, wide base. The Structure 24 is a neutral trainer but has stability features which make it very stable. The smaller air bag is situated under the ball of the foot and the outline can be felt underfoot which some runners may find lumpy. The Structure 24 also has a Zoom Air unit in the forefoot but it is smaller and thinner than the air bag in the Pegasus 39. There is an additional air unit in the heel for extra cushioning. The air unit is 20 PSI in the men’s version compared to 15 PSI in the women’s version which means that the women’s version is softer.

Inside the midsole of the Pegasus 39 is a large, thick forefoot Zoom Air unit which adds a springy sensation to the ride of the Pegasus 39 thus increasing responsiveness. It rides medium soft which means that it is suitable for slow runs, recovery runs or slightly faster runs.

The midsole of the Structure 24 is made from a new foam called CMP-010. It rides medium firm which means that it can be used for tempo runs, marathon-paced runs and even long, slow runs. The midsole of the Pegasus 39 is made of React foam which Nike calls their most “complete” foam.

Nike air zoom pegasus 34 mens