Wearing new clothes, new shoes or eating new foods on race day is a no-no.

New is usually good. But, on a day when you have a race, new isn't good. On a race day, new can be run-destroying, disastrous and downright dangerous.

When buying new shoes, you should break them in for at least a week before you wear them on a long run. When I buy new running shoes, I don't actually wear them for running until they're broken in. Instead, I wear them an hour a day just walking around the house. After a week of doing this, they're broken in enough that I can safely wear them on a short run without getting huge blisters. If I'm planning on wearing new shoes for a race, I break them in, then wear them for at least another week running short distances before I even think about wearing them for a race. On race day, you want to be wearing shoes that are already broken in to the shape of your foot and that you're completely sure are comfortable. Even experienced running shoe buyers sometimes get a pair of shoes that take a couple of weeks to feel right, so the last thing you want to do is find out they're not comfortable in the middle of a big race.

Same goes for running clothes. New clothes can sometimes chafe or scratch. If you're running in a big race and especially if it's a hot day, wearing new running clothes could give you a nasty surprise after a few miles. I always wash them first before wearing them and use a fabric softener. Then I wear them on a short run so I can be sure they fit and that they're lightweight enough. Running bras especially can be a pain and I've had more than my fair share of chafe marks from a bra that was too constrictive or that didn't wick away moisture correctly.

As far as new foods go, even healthy foods can give you stomach ache. You don't want to eat a new healthy snack on race day then find, half way through the race, you're doubled over with stomach cramps because it's just not sitting well. Any new foods, either test out a few days before a race or after it. For race day, stick with foods you know give you energy and that your body doesn't interact badly with.