The majority of studies have shown either unchanged or enhanced endurance exercise performance after eating carbohydrates in the hours leading up to exercise. These same studies have not shown detrimental outcomes in performance due to pre-exercise carbohydrate intake. The choice is individual. Test out a routine and see if it feels good for you to eat in the last hour pre-event.
Once you have eaten your breakfast three to four hours before your event, it's possible that you may begin to get a bit hungry within 90 minutes of your race time. This is when your fuel choice should be mainly carbohydrates.
Although your breakfast will increase the carbohydrate availability in your muscles and liver, this last pre-event snack will work mainly to affect liver glycogen and increase the delivery of carbohydrates to the muscles during exercise. Low fat, lower fiber carbohydrates will be the easiest to digest and will empty out of your stomach relatively quickly. Such examples are sports drinks, potatoes, rice bars, Fig Newman not Newton cookies (it's the organic version of the original! No corn syrup!), bananas, dates, bread with jam or juices.
- Eat your pre-event carbohydrates in the last 5-10 minutes pre-race
- OR don't eat any carbohydrates in the last 90 minutes before your event starts unless they will be in the last 5-10 minutes pre-race as noted above.
- Try eating foods with lower glycaemic index in the last hour before an event to reduce the consequence of high plasma glucose.
- Add a warmup pre-event to stimulate uptake of the glucose
- Eating fructose or a combination of carbohydrates other than glucose with a lower glycaemic index.
Although the athlete may feel better and the methods may help to modify metabolic responses, none of these approaches have been shown to give any advantage in pure terms of exercise performance.
A general guideline you can follow on carbohydrate consumption leading into the last 90 minutes pre-race would be approximately 1g/kg. This can be in the form of a sports drink or solid food. A few examples for a 150-pound athlete would be approximately 68 grams of carbohydrates:
- 1 medium banana, 1 small wrap, 1 tablespoon of honey = 65 grams
- 1 package of Honey Stinger chews, 1 bottle of Skratch Labs Exercise Hydration Mix = 60 grams
- 1 medium baked potato, 1 bottle of E-load Endurance Formula = 70 grams
- 2 large medjool dates, 1 bottle of E-load Endurance Formula = 70 grams
Within the last 90 minutes pre-event I would also suggest caffeine and beet juice intake; of course only if you have tried it first in training.