Find your comfort zone
Jeff Dengate, senior editor, shoes and gear, says: Run in what you know. Race day is no time to test the shirt you just bought at the expo. Instead, wear what you've been training in -- what you know will remain comfortable and chafe-free, mile after mile. And be sure to keep an eye on the weather forecast. Even if unseasonably warm daytime highs are predicted, beware that it can be cold in the morning as you wait for the start of the race. Bring a hat, gloves, and old sweats that you won't mind throwing away once you begin running. Finally, be sure to pack sunscreen; there are very few shady spots on the course between Hopkinton and Boston.