Your body needs fuel to achieve the high intensity of a 5K race, but eating the wrong foods can lead to some unpleasant stomach problems on the course. You want to eat tried-and-true foods — that is, those you've eaten before a run previously — that are easily digestible and include low-fiber carbs, with a little bit of protein.
It's not just about what you eat immediately before the starting gun. The dinner you have the night before the race can make an impact, too.
Read More: Good Foods to Eat Before a Morning Run
The Night Before
The traditional wisdom says to "carb-load" the night before a race; however, it's not necessary before a 5K. That's not to say that you should avoid carbs — just don't go overboard.
Pick a healthy dinner that you've eaten before a run previously, as then you know your body digests it easily. Consider a combination of chicken and fish and pasta or rice, plus vegetables. Skip cheeses or heavy cream sauces, as it could cause lingering GI troubles for your race the next morning.
The Morning Of
If you have enough time, eat a light breakfast three to four hours before the 5K begins. This gives your body enough time to break down nutrients and fill your muscles with glycogen.
Again, choose foods that have low-fiber carbohydrates but are low in fat. A piece of whole-wheat bread with peanut butter or cold cereal and fruit make for a healthy, light breakfast. Bananas in particular are a good idea because they're high in potassium, an electrolyte that's lost in sweat. If you didn't have time for a full breakfast, a banana 30 to 90 minutes before the race gives you some energy to get through.
It might also be helpful to drink a little bit of caffeine, as it can help give you more energy. Only do this if you're a regular coffee drinker, though; it's a diuretic and can give you cramps and dehydration during the 5K if you're not accustomed to it.
In addition to eating a healthy meal, it's vital to stay hydrate. Drink at least 64 ounces of water before your race; however, you should stop drinking 30 minutes before the starting gun. Having too much water in your system can give you stomach cramps, make you feel bloated, force you to an unexpected potty stop and even cause you to get a slower final time.
Read More: What to Eat When Training for a 5K