We know temperature extremes can make even the perkiest people wilt, but running shoes?
Researchers at the University of Oregon checked changes in the cushioning and stability properties in shoes worn by runners who worked out in cold (30 to 35 degrees F.) and hot (90 to 95 F.) weather.
In cold conditions, cushioning properties of moderately stiff midsoles dropped up to 50 percent, says researcher Barry T. Bates, Ph.D. This could mean up to 1.5 times greater impact forces are generated on the body during winter runs compared to summer. Shoes with gel- and air-filled components are less affected by temperature changes, says Bates.
In hot conditions, shoe stability suffered. A stiff shoe became more flexible, which is bad news for the many runners who require stiff shoes to prevent overpronation. Runners who overpronate (a foot rolls inward) often develop foot and knee problems.
Advises Bates: "If you do a lot of running, are prone to injury, and live in a climate with large temperature differences, switching with the seasons from one type of running shoe to another might prevent injuries."