Although it may be tempting to dismiss the difference between men and women's running shoes as a marketing gimmick, history demonstrates that men and women have very real, differing needs for running. Originally, running companies offered a scaled down-men's shoe in more appealing colors for women -- hence the sarcastic phrase "shrink 'em and pink 'em" -- but this quickly proved inadequate. Women found that if the heels didn't slip, the forefoot was too tight for comfort. Companies that took the time to research and design the appropriate footwear found that sales quickly skyrocketed.
The Shape of the Shoe
The primary difference between men and women's running shoes is the width of the shoe. Compared to the corresponding men's shoe, women's shoes are built wider in the forefoot and toe area and narrower in the heel, reflecting the gender differences in foot shape. Furthermore, men's shoes are generally wider and sized larger than women's shoes. Some shoes, despite being branded as the same shoe for different genders, have different midsole materials or heel support, affecting the fit, comfort and even weight of the shoe.
Although not commonly known, the Q-angle is the angle of incidence of the quad muscle relative to the kneecap. Because women generally have wider hips than men, they have wider Q-angles, which causes them to pronate more and require extra support in the shoe. Pronation refers to the motion of the inner and outer ball of the foot with the heel bone. Overpronation, where your foot pushes off almost completely from the big toe and second toe and fails to spread shock evenly, and underpronation, where the weight of your foot fails to transfer to the big toe and forces the outside of the foot to bear most of the weight, can lead to serious injuries over time. Designers and developers who take this into account often use a different material for the midsole or outsole on a women's shoe than they will on the men's version.
The Effect of Weight
Women have, on average, 15 percent less muscle than men, causing them to weigh less than men of comparable height and shoe size. Therefore, the midsole in a woman's shoe is designed to sustain 15 percent less impact as each foot strikes the ground. Because of this, women's shoes usually contain a lighter and softer midsole than the men's version. Furthermore, while both men and women's shoes have flex grooves carved into the forefront of the outsole, these grooves will be significantly deeper on the women's shoe. This is because women's lower-body mass makes it harder to flex the midsole, so the grooves are added to help.
Athletic shoe companies have created a wide range of shoe types designed to cater to various preferences and requirements. However, if a woman has a wider foot or a man has a narrower foot, he or she may find that the opposite gender's shoe actually provides a better fit. Although there are significant differences between men and women's running shoes, these differences should not prevent an individual runner from finding his or her perfect fit.