High heels have been made from all kinds of materials throughout history. In the early years, leather and cowhide was preferred. As civilizations progressed, silk and patent leather were introduced, while cork and wood were utilized as cheap resources in times of war. After the World Wars and the increase in production of steel, the actual heel was a piece of steel wrapped in some kind of material. This has enabled designers to make heels taller and skinnier without them snapping. The soles below the ball of the foot of Ballroom shoes can also be made of materials like smooth leather, suede, or plastic. 
Researchers have also found that because women tend to have wider hips than men, our feet are more likely to strike the ground toward the outside of our shoe soles. The inward rolling of the foot that results from this is known as pronation, which explains why more women are believed to overpronate than men. Some women’s running shoes account for this increased tendency with different materials used for support through the sole.
Studies on foot shape have shown that women’s feet aren’t just smaller, narrower versions of male feet—there are differences in overall shape that affect shoe fit. Women’s feet tend to be comparatively wider in the forefoot, with a narrower heel. Running shoe makers take this statistical difference into mind when designing their shoes, and generally build their shoes with different heel shapes and sometimes different heel materials between the two models of the same shoe. Companies like Altra, with its Fit4Her technology, specifically design shoes that anatomically mirror a woman’s foot.
The Turbo 2 is built for women who want to go fast, with a soft, springy ZoomX foam in the midsole borrowed from the record-setting Vaporfly Flyknit 4%. Typically, an EVA foam midsole will compress easily and then take its sweet time recovering shape. But ZoomX technology has blown us away with its quick compressibility and immediate rebound. Nike has added a thin layer of React foam to the bottom so the shoe will hold up for longer, as well as a rubber outsole grid for traction. Overall, this is a high-mileage, versatile shoe that combines the fit and feel of a workhorse Pegasus with the lightweight speed of a racing flat. Just be warned that upper feels slightly less secure than the first Peg Turbo.