Running Tip #23. Make sure carbs are a large (~70%) part of what you eat this week (pasta, potatoes, bread) to fuel you on race day. Don’t simply eat more of everything especially as you are tapering.
A big meal the night before is a myth. Have simple carbs, some protein, avoid too much dairy or high-fiber. Hydrate with electrolytes the day before. Plan your race morning breakfast 2 or 3 hours before to restock glycogen. I like a banana, bagel with almond butter, and water with electrolyte tablets like NuuN!