Race Day Nutrition

Ilana Katz, MS, RD, LD

It is that time again. Racing season is around the corner and of course the obvious nutrition question on everyone's mind is “What should I eat on race day for optimal performance?” Not a simple question. During endurance races, athletes may metabolize up to 500 calories per hour, yet the body's capacity for quick nutrient absorption or the practicality of providing this amount of fuel while racing, is limited. The following recommendations and practical solutions offer general guidelines to any athlete engaged in endurance sports.

CARBOHYDRATES– The preferred source of fuel

Since the human body oxidizes carbohydrates at a rate of 0.5g – 1.0g per minute, a maximum of 60g of carbs per hour is recommended. Athletes can train their bodies to absorb 100g carbs/hour. Although unnecessary, this extreme amount can help endurance athletes (events 90 minutes or more) further reduce their risk of “hitting the wall”. Strive for moderation, taking into consideration, the distance, the time, and perceived intensity of the race. For endurance athletes, a general rule for individualizing carbohydrate intake is 1g per kg body weight per hour (70 kg athlete needs 70 g of carbs/hour) at 15 - 20 minute intervals. Although this may be a simple calculation to strive towards, practice during training sessions and allow your body to build up to these levels over the course of your training.

The exponential advancement in sports nutrition products provides a plethora of texture, flavor, and formulas. Solids, gels, and liquids are all effective, but individual tolerance of certain foods as well as quantity varies by individual and by session. Furthermore, most sports products often require water to aid with digestion. For every 15g of carbs, 8 oz of water is recommended. Since digesting nutrients at an increased intensity is difficult, irrespective of the event time or distance, eat at least 0.5 g of carbs per kilogram of body weight within two hours before the race.

Carbo-Loading

Carbo-loading is a strategy to improve glycogen storage prior to a race and reduce the risk of premature fatigue. A safe and effective technique is to gradually increase carbohydrates each day starting a week before competition while simultaneously tapering exercise. Recent research disagrees with older strategies of carbo-loading, which involved extreme depletion of carbohydrates while exercising intensely. Simply changing to a very high carbohydrate diet, combined with a few days of rest will effectively increase muscle glycogen.

FATS

Although fats are vital for physical activity, most individuals have enough body fat stored for energy during prolonged workouts. Increasing fat intake will only lead to less consumption of carbohydrates impeding glycogen stores (glycogen being the immediate source of fuel for physical activity). Furthermore, fats have a tendency to slow down metabolism. Consider fats as the reserve tank of fuel, and keep them to a minimum during training and racing.

PROTEIN

Protein, in itself does not provide energy unless glycogen and fat are depleted and like fat, slows metabolism. You will typically get enough protein for race day if you eat high quality proteins (such as whey, egg whites, milk, soy) as part of your daily intake. Small amounts of protein during a race may reduce muscle damage. Recovery, however, requires protein (Recommended ratio - 3 carbs to 1 protein).

HYDRATION AND ELECTROLYTES

Maintaining proper fluid balance is vital for optimal performance.

2 hours before: 8-16oz. of fluid

15 min to ½ hour before: 4 – 8 oz

During: 4 – 8 oz every 15 – 20 minutes

Post event: at least 16 oz / 16 – 24 oz per lb sweat lost^*

Drink to replace sweat. Do not over drink.

^*Sweat lost is the difference in weight before and after the event (weigh with no clothes).

Sodium and potassium are electrolytes which help the body maintain proper water balance, are lost in sweat and need to be replaced. Heavy sweaters should consume 500 – 700 mg sodium and 100 – 400 mg of potassium per hour. Sports drinks are scientifically formulated for electrolyte replacement and simultaneously provide hydration options. For a variety of texture and taste, salty foods, salt tablets, extra sodium gels, Gatorade Endurance^T, bananas and pretzels, are easy and convenient options while racing.

FIBER

To prevent gastrointestinal distress, keep fiber to a minimum. Fiber is difficult to digest, especially during high intensity. Avoid whole grains and fruits with skin on race day.

BEST CHOICE OF FOODS

Therefore, best choice of race day nutrition incorporates foods that are ultra low in fat, low in protein, low in fiber, and high in carbs:

30 minutes before: Powerbar : 41g carbs, 2.4g fat, 9g protein
Immediately before/during race: Specially formulated bars (eg. marathon bar): some bars are higher in fat, but great tasting treats help maintain motivation.
During race : Banana: 36g carbs, lower in fiber than other fruit, high in electrolytes, 0 g fat (perfect)
Pre-race meal (2 hours before): Slice of white bread- 12 g carb, minimal protein and fiber. Great for glycogen sparing. Has a higher glycemic index (faster insulin release) thus more potential for glycogen sparing than whole wheat bread.

Mastering race day nutrition enables optimal race day performance. Always use products you trained with versus trying anything new on race day to reduce the risk of gastrointestinal distress. A good practice is to determine what products will be provided by sponsors and perhaps use those products in your training.