This is a good question and one that we hear frequently as the weather improves and runners turn their focus toward training for their next distance event. Unfortunately, the answer is not the same for every runner. The best answer is it depends. Probably the most important factor is what type of feet you have. If you have high-arched feet, and the arches don’t drop when you stand on them, then your feet are rigid and therefore less able to absorb shock. In general, you will do better with a shoe that emphasizes cushioning. You don't need as much support, since your feet already have plenty. Cushioning inserts may also help decrease your chance of running injury.
On the other hand, if your feet are quite flat, and the arches drop when you stand on them, then your feet adapt well to the running surface. However, this type of foot does not have much support built into it, and your shoe choice should be one that emphasizes support. “Motion control” shoes (shoes that control pronation) may be a good choice. No matter what shoe salespeople may tell you, cushioning is sacrificed for support and vice-versa.
You should wear shoes that are well broken-in when competing. Most runners elect to wear the shoes that they train in. Some elite runners choose to wear a lighter pair of shoes, often called “racing flats,” to compete in, in the interest of maximizing every advantage. The problem with this is that lighter shoes may not be as effective in either cushioning or supporting the foot. If you do choose to run in racing shoes, complete a few training runs in them before the competition.
Finally, a quick word about barefoot running and footwear: Most runners who run with a forefoot-striking “barefoot” style wear some sort of light footwear. However, the minimalistic shoe style marketed to these runners can be quite expensive. The benefits of this style of running can be achieved just as effectively in a less costly shoe, as cushioning and support from the shoe are much less important issues with this running style.
Dr. William W. Briner is a primary care sports medicine physician specializing in the non-surgical treatment of acute and over-use injuries in active patients. Dr. Briner has served as a team physician for the WNBA Chicago Sky, the U.S. national soccer teams, and several high school and college teams. He is currently the head team physician for the U.S. national volleyball teams, in addition to chairing the Sports Medicine and Performance Commission for USA Volleyball.