When you compete in a triathlon, you will actually need two different types of triathlon shoes: running shoes and cycling shoes. Each shoe is vastly different from the other, which means the considerations for purchasing the different triathlon shoes will vary according to the shoe's purpose. Triathlon shoes for running should be lightweight, should feature an easy-to-use fastening system that does not use laces, and should wick moisture away from the foot easily. Cycling triathlon shoes should be stiff, should accept the proper cleat for your pedals, and should also be easy to put on and take off for quick transitions.
Triathlon shoes for running should be flexible and lightweight, just like regular running shoes. Shoes designed specifically for triathlons, however, will have other features specifically included to improve performance during transitions and running periods. A good pair of triathlon shoes will not have laces, since laces can be cumbersome and difficult to tie during transitions. Drawstring systems are common, and these are the easiest and quickest systems to use. The shoe can be tightened snugly around the foot simply by pulling on the end of the drawstring, eliminating the time needed to tie laces.
Many triathletes run without socks, since putting on socks during the race can add time to the transition. A good triathlon running shoe will fit snugly when you are not wearing socks, so be sure to try on the shoe without socks before purchasing. The shoe should fit snugly enough that the foot does not move around within the shoe, causing hot spots or blisters. Some triathlon shoes feature run-off channels or moisture-wicking materials that allow water from the swimming leg of the race to drain away from the foot. Such shoes are a good investment, as they can help prevent hot spots and blisters.
Cycling shoes for triathlons should also feature a quick fastening system. Velcro® straps are a common method of securing the shoe, and other ratchet systems can also be a quick option, though they are more difficult to adjust properly than Velcro®. The sole of the cycling shoe should be very stiff and light. Plastic is a common material for cycling shoe soles, but carbon is a better option, because it is both stiffer and lighter than plastic. A stiff sole ensures more power from the pedal stroke makes it to the wheels, rather than to the flex of the shoe. Consider buying a pair that also fits snugly with no socks on, as this will improve your transition time as well.