Other runners can eat within an hour of a hard run with no adverse side effects.
Eat up: Generally speaking, the longer the run, the more carbs you need. For races that last 90 minutes or longer, "increase your daily
[cyclingTips]: I wouldn’t worry about eating anything for the first hour of the race. The fuel from the night before and breakfast should be more than enough to keep you going. It’s not easy to eat while you’re running so this takes care of the first segment of the race.
Runners Connect » Nutrition Articles » What to Eat Before a Run.
Eating two to three hours before race time gives you time to digest your breakfast so the energy it provides is ready to use. Running will divert blood from your stomach to your muscles, so the food you eat won't be properly digested.
Related Article: How To Fuel For Workouts and Runs. What you choose to eat the day of the race, however, is just as important as what you eat the week before. In the two to four hours before the race, eat protein and simple carbs and drink water or sports beverages.
Most runners I know will eat their breakfast about 2 hours before the race's start time, to be sure they won't be running with a heavy stomach.
What to Eat Before a Long Run. What I ate the day before my half marathon race.
Drink at least two to three cups of fluid before the race, one to two during, and at least one cup after. For a 5K runner, water will suffice for hydration. If you’re expecting to run for longer than an hour, however, you should also be taking in sugars and sodium, which you can do by drinking a...
Eat a small meal one to two hours before the starting gun goes off. If you feel hungry, have a snack about 30 minutes before you run.