Optimal nutrition is attained with sound dietary practices that are applied on a continuing basis, not just a few hours before or during competition. Nutritional factors can conceivably influence performance at almost any stage during training or competition.
Food in endurance sports training programs should provide:
Adequate fluids to prevent dehydration
Energy intake that is high in carbohydrate, low in fat, adequate in protein and that maintains desirable body weight
Sufficient amounts of vitamins and minerals
The ultimate competitive ability of an individual is in part, related to his or her capacity to train maximally. Consequently, every effort must be made to ensure all nutritional needs are met during this period. Proper nutritional management during training will also serve to support the athlete during active competition.
When carbohydrate and fluids are deficient in the diet it leads to fatigued muscles, weakness and tired feeling which leads to decrease in performance. The following explains why this happens and why the High Performance Diet is important to follow.
 
Nourishment Before Exercise
The goals of the pre-exercise meal:
Prevent low blood sugar and associated symptoms (light-headedness, blurred vision, fatigue, and indecisiveness)
Prevent feelings of hunger
Provide energy for working muscles
The pre-exercise meal is important, especially before morning exercise. The body has to draw on the liver’s supply of glycogen for energy. This supply eventually runs low if you skip breakfast and blood sugar decreases, giving you a hungry, tired feeling. The lowering of fuel supply to the brain can also have a negative effect on your mental power that can further hinder performance. Consuming a meal, or at least a light snack, before exercise helps to replenish liver glycogen and helps to maintain normal blood sugar levels and endurance. Complex carbohydrates are ideal because they are quickly digested and absorbed into the bloodstream, leaving the stomach quickly so there is less chance of indigestion and nausea during the event. Research has demonstrated that food ingested 3-4 hours prior to exercise is used for energy during exercise. However, one has to realize that one can’t rely on the morning’s intake alone and that dietary intake of 2-3 days preceding the exercise can affect performance as well.
The pre-exercise meal should be low in fat. Try to avoid fat 12 hours before exercise because fat leaves the stomach slowly and may cause a bloated, heavy feeling. Try to avoid high protein foods right before exercise because proteins require more energy to digest and also cause an increase in urine output promoting the loss of needed fluid. You also need to avoid high fiber and gas-forming foods; these foods can cause stomach discomfort during the exercise. High fiber foods are excellent choices for general nutrition, but are not recommended for the pre-exercise meal.
You should always start exercise in a fully hydrated state; adequate fluid intake should start 24-36 hours before exercise. Drink at least 8 to 16 ounces of fluid 2 hours before exercise and 8-20 ounces water approximately 15 minutes before exercise. Avoid starting a workout thirsty. Liquids should be cool for faster absorption. You also need to make a special effort to drink more water in higher altitudes and warmer temperatures.
 
Nourishment During Exercise
Goals for nourishment during exercise:
Replace both muscle glycogen and fluid losses
Maintain normal blood sugar levels
Provide source of energy for the exercising muscles
Replenishing carbohydrate and fluid throughout exercise that lasts over an hour can postpone fatigue and prolong peak performance and ensure greater stamina by keeping muscle glycogen stores filled.
Scientific studies shows that after one-hour of continuous exercise, athletes are likely to tire due to carbohydrate depletion. Research data also suggests that fatigue can be delayed by as much as 30-60 minutes by eating carbohydrates during exercise: 30 to 60 grams of carbohydrate/hour (120-140 calories) appears to be an optimal range of carbohydrate intake for maintaining or improving performance. Ingesting greater quantities of carbohydrate does not further improve endurance and may, in fact, hinder performance. During exercise of moderate intensity, blood flow to the stomach is 60% to 70% of normal, so the athlete can still digest food. Depending on the sport, the food can be provided as a solid food or a liquid (Sport Drink). Since liquid foods leave the stomach faster than solid foods, the athlete may want to experiment with liquid meals to determine if they offer any advantage. The athlete should keep in mind anecdotal reports that too much liquid may “slosh” in the stomach and contribute to nausea. Therefore, any new meal should be experimented with during training to determine its level of acceptance.
In addition to replacing carbohydrates, the athlete should be careful to replace fluids lost through sweat. Carbohydrate-containing fluids, such as sports beverages, replace both muscle glycogen and water losses; they are the best choice for both good nutrition and top performance. Sports drinks containing between 14-19 grams of carbohydrates (6-8% carbohydrates) and 50-80 calories per 8-ounce serving are appropriate before or during activities lasting longer than 60 minutes. The carbohydrates and electrolytes can help increase the rate of fluid absorption from the gastrointestinal tract.
Eating solid food or concentrated carbohydrate solutions or gels on a training ride may be necessary to ward off hunger pangs during the ride, to aid in recovery after the ride, and to serve as a way to meet daily caloric needs.
Research suggests that the body is better able to handle a concentrated nutrient load while riding. Sweating is generally less during cycling than during running because of the enhanced cooling effect provided by the wind. Consequently, dehydration is less of a risk and the need for fluids is not as critical as it is during running. The decrease in gastric emptying that will occur when you eat food during exercise is less likely to lead to gastrointestinal distress during cycling because there is less up-and-down jarring and bounding.
 
Nourishment After Exercise
Goals for after exercise nourishment:
Replenish carbohydrate (glycogen) stores to maintain exercise performance on a day-to-day basis.
Replace fluid that has been lost during exercise.
If you want to be ready for the next day’s workout, you must replenish your carbohydrate reserves so that subsequent exercise performance is not impaired.
After the carbohydrate supply has been depleted, it takes 24-48 hours for full recovery. Muscles are most receptive to replacing muscle glycogen within the first 2 hours after a hard workout. Research shows that full recovery can be achieved if carbohydrate intake (40-60 grams) begins immediately after exercise or within the first 30 minutes after exercise, and to continue at 2-hour intervals up to 4 hours. This is especially important if you are working out twice a day. Failure to consume carbohydrates at this time may hinder optimal glycogen recovery and endurance.
Not only the timing of carbohydrate intake but type of carbohydrate consumed can affect the rate of glycogen synthesis. Glucose appears to refuel the muscles better than fructose (sugar in fruits, juices, and sodas). Research shows that athletes who consume glucose after exercise have a 50% faster rate of glycogen repletion than those who consume fructose.
Fluid replacement should be at least 8 to 16 oz of fluid after exercise, or 1 pint (2 cups) per every pound of body weight lost. Only athletes who exercise for more than an hour daily with heavy fluid losses from sweat are at risk for depleting sodium and potassium. Most can replace these electrolytes with the fluids and food they consume after exercise. For those who report that exercise “kills the appetite,” sport beverages can provide adequate carbohydrates and also supply needed fluids. Sport beverages can also be helpful after exercise when an athlete is unlikely to make appropriate selections, or when the right foods are unavailable.
You should note that experience has shown that all athletes must learn, often through trial and error, what foods work best for them. Specific recommendations can be made only with the knowledge of the athlete and the athlete’s sport. For example, some runners can eat within 1 hour before racing, while others avoid food to reduce the risk of gastrointestinal distress. Some gymnasts want a little food to settle a nervous stomach, while others are so nervous they feel sick and are unable to eat. The pre-exercise meal food preferences also vary from sport to sport. For example, cyclists are likely to eat more than runners, who fear gastrointestinal problems related to the jostling that occurs with running. Each athlete has unique food preferences and aversions, food preferences may vary depending on the type of exercise, the level of intensity, and the time of day they are consumed. The guidelines that are provided for you should be viewed as a starting point for recommendations that can be used during training. These are general guidelines.
Diet to Improve Performance
Optimal nutrition is attained with sound dietary practices that are applied on a continuing bases, not just a few hours before or during competition. Nutritional factors can conceivably influence performance at almost any stage during training or competition.
Performance Diet Guidelines
1. Energy intake that maintains desirable body weight
2. 6-10 grams of carbohydrate per kilogram body weight/day (about 60-70% of total calories)
6 grams/kilogram body weight for one hour of training per day
8 grams/kilogram body weight for two hours of training per day
At least 10 grams/kilogram body weight for three hours of training per day
3. 10-15% protein or 1.5-2.0 grams/kilogram body weight/day
4. 20-30% fat
5. Plenty of fluids to prevent dehydration
6. Sufficient amounts of vitamins and minerals
The ultimate competitive ability of an individual is in part, related to his or her capacity to train maximally. Consequently, every effort must be made to ensure all nutritional needs are met during this period. Proper nutritional management during training will also serve to support the athlete during active competition.
PRE-EXERCISE MEAL
Fluid needs:
Drink lots of fluid 24-36 hours before exercise
Drink at least 16 ounces of fluid 2 hours before exercise
8-20 ounces water approximately 15 minutes before exercise
Drink at least 4 to 8 ounces of fluid immediately before exercise
Carbohydrate needs:
1-4.5grams/kilogram body weight 1-4 hours before exercise (1 gram per kilogram one hour before; 4 grams per kilogram four hours before)
or 300-800 calories 1-4 hours before exercise (300-400 calories one hour before; 700-800 calories four hours before)
or 2 calories/pound body weight 1 hour prior to exercise
If consuming a Sports Drink*, drink 16 oz (.5 liters) 1 hour before exercise
If consuming a High-Carbohydrate Energy Drink* or Sports Shake*, drink 16 oz (.5 liters) 2-5 hours before exercise
If consuming a Sports Bar*, one bar 2 hours before exercise
If consuming Energy Gel*, 1 packet prior to exercise (when taking an energy gel make sure to drink plenty of water with it).
Reduce the size of the meal the closer to exercise it is consumed
*Note: During exercise lasting less than an hour there is little evidence of physical performance differences between consuming a sports food and plain water.
Preparing for Morning Event/Exercise
The night before:
Eat hearty, high carbohydrate dinner and bedtime snack
Drink at least 8 ounces of fluid with meals and snacks
The morning of:
Eat a light, high carbohydrate, low fiber snack or breakfast (allow 3 hours for the food to digest)
Drink at least 8 ounces of fluid with meals and snacks
If your body can’t handle any breakfast, eat a late snack before going to bed the night before
Preparing for Afternoon Event/Exercise
The night before:
Eat hearty, high carbohydrate dinner and bedtime snack
Drink at least 8 ounces of fluid with each meal and snack
The day of:
Eat hearty, high carbohydrate, low fiber breakfast
Eat light lunch that is moderate in calories, low in fiber and high in carbohydrate (allow 4 hours for food to digest)
Drink at least 8 ounces of fluid with meals.
Preparing for Evening Event/Exercise
The day of:
Hearty carbohydrate- rich, low fiber breakfast and lunch
Drink at least 8 ounces of fluid with meals
Moderate calorie, high carbohydrate snack 1 or 2 hours prior to event or exercise
All Day Event
The day before:
Cut back on exercise
Eat high carbohydrate meals at breakfast, lunch and dinner
Drink at least 8 ounces of fluid with meals and snacks
The day of:
Follow the “pre exercise” and “nourishment during exercise” meal plans
Plan to snack every 1-1/2-2 hours on complex carbohydrates
Athletes should initially test the effectiveness and timing of pre-exercise meals on exercise capacity during training and not prior to an important competition. If you know that you will be unable to tolerate any food before exercise, make a special effort to eat well the day before and have an extra-large evening snack.
During Exercise
Fluid needs:
4-10 ounces water every 10-20 minutes
Avoid concentrated beverages (soda pop, fruit juice, fruit drinks)
Carbohydrate needs:
If consuming a sports drink*, 4-8 ounces sport drink every 15-20 minutes
If exercise is longer than an hour
-after the first 30 minutes, 16-40 ounces sports drink/hour.
-if consuming solid food, 7-15 grams carbohydrate every 15-20 minutes or 30-60 grams carbohydrate/hour
Maximum amount of carbohydrate appears to be in the range of 60-75 grams/hour (1.0-1.5 grams/minute)
*Note: During exercise lasting less than an hour there is little evidence of physical performance differences between consuming a sports food and plain water.
After Exercise
Fluid needs:
1 pint water/pound body weight lost
Drink at least 8 to 16 oz of fluid after exercise.
Carbohydrate needs:
40-60 grams ASAP or within the first 30 minutes after exercise, and at 2 hour intervals up to 4 hours after exercise
or 1.5 grams carbohydrate/kilogram body weight within the first 30 minutes after exercise, and at 2 hour intervals up to 4 hours after exercise
If weight is less than 60 kg then 60 grams will be at the maximum end of range
If weight is greater than 60 kg then 60 grams will be at the minimum end of range
Maximum 1.5/kg body weight at 2 hour intervals up to 4 hours after exercise
NOTE: 1 kg (kilogram) body weight = 2.2 pounds
If solid food is hard to obtain or sounds too filling after exercise sports food can be extremely helpful. They allow you to consume large amounts of carbohydrate without providing much bulk. Sports foods such as High-Carbohydrate Energy drinks, Sports Bars, Sport Shakes and Energy Gels can be consumed immediately after exercise and 1 hour intervals to deliver 1 gram carbohydrate/kilogram body weight.