Having a shoe that fits properly and supports your stride is essential. Some people are over-pronators, their feet fall inward when they strike the ground, or supinators, they strike with the outer edge of the heel and forefoot. Others may have flat feet or high arches that require a special kind of shoe. There are shoe stores that will actually do a gait analysis to find out what the best shoe is for you, Dr. Steinberg said, naming New Balance as an example.
You also have to be wary of how long you're using your running sneakers, Dr. Steinberg advised. Running excessive mileage on the same pair of shoes, he said, is not a good idea. The baseline is around 400 miles, so if you've surpassed that on the same pair of shoes, it might be time for new ones. Dr. Steinberg suggests rotating between two pairs to avoid this problem, too. And, one last note: don't put on a fresh pair the day of the marathon.