Fueling the day before and day of the race
For races greater than an hour, like a marathon, starting carb loading about 3 days before the race, as you taper off on your running, can be helpful. Carb loading allows you to increase the amount of glycogen stored in your muscles and liver. Glycogen is stored glucose and provides quick energy for the run. Running low on glucose during the race leads to decreased performance and inability to complete the race. Ideally, you have tried various foods and sports products during training, to know what works well for you.
The day before the race, load up on easily digested carbs
Meals should be high carb, lower in fiber, and low fat, with some lean protein for repairing muscle damage.
The last meal of the day before should be low in fructose, to avoid stomach upset or diarrhea. Burgers, fries, and pizza are not recommended!
Baked potato with fat free Greek yogurt and salsa.
Sub sandwich on French bread with turkey, mustard, or a little light mayo, and reduced fat cheese.
White pasta with small amount olive oil, parmesan, and a little basil or oregano
White rice with chicken breast or beef loin, and a little soy sauce
Pretzels, oyster crackers
Cream of wheat with brown sugar
Toast or bagels with honey
Milk (if you’re not lactose intolerant).
3-4 hours before the race, low fiber, low fat, easily digestible
Pretzels, oyster crackers, English muffins, toast with honey. Bagels; limit/avoid cream cheese and jelly; could use honey.
Water. Don’t overhydrate or underhydrate
Avoid juices and fruit, or anything with corn syrup. (at this point, fructose may lead to diarrhea).
During the race
Hydration: water and sports drinks.
Sports drinks help replace electrolytes lost in sweat and also provide a source of glucose for continued energy.
Sports beans, gels, and chews. They provide electrolytes, and a more concentrated source of carb than sports drinks, to maintain a normal blood sugar after your stored glycogen is depleted.
You can include some easily digested carbohydrate foods during your run, such as pretzels or oyster crackers, if you like and you tolerate them. Try this out during training, before an event, to be sure you will tolerate without digestive upset. Your body may just need time to adjust to this type of fuel during the run.