drtbear1967
Musclechemistry Board Certified Member
Carbohydrates – The Master Fuel
A diet rich in carbohydrates increases endurance performance because of the extra store of carbohydrates in the muscles and liver called glycogen. Work completed in the early 1980’s by David Costill at Ball State University showed that if athletes did not consume a diet high in carbohydrates on a daily basis, they would experience chronic fatigue and poor performance. It is well documented that endurance athletes need to replenish carbohydrate stores in the body, especially during periods of intense training. Consuming carbohydrates during workouts lasting over one hour can also benefit performance and delay onset of fatigue. Several recent studies have shown that athletes who participate in stop-and-go sports, such as basketball and soccer, may also need to focus on consuming more carbohydrates. This is not surprising since it is well-known that carbohydrates, when compared to protein and dietary fat, are the most efficiently broken-down and metabolized form of energy for the body. Athletes doing stop-and-go activities were found to have better speeds and to delay fatigue when consuming a higher carbohydrate diet.
Recommended Intake of Carbohydrates
Depending upon the training routine, athletes need to consume at least 50 percent, but ideally 60-70 percent of their total calories from carbohydrates. This percentage is only a guideline for estimating carbohydrate needs. Depending upon the length of training sessions, an athlete’s carbohydrate intake should be between 2.5-6.0 grams per pound of body weight, with longer training times requiring the higher number of grams.
Carbohydrate Intake Before, During, and After Exercise
before exercise:
The pre-exercise or pre-training meal serves two purposes:
It keeps the athlete from feeling hungry before and during exercise
It maintains optimal levels of energy for the exercising muscles.
Carbohydrate intake before exercise can help to restore sub-optimal glycogen stores, which is critical for prolonged periods of exercise. While allowing for personal preferences and psychological factors, the pre-event meal should be high in carbohydrates, non-greasy, and readily digestible. Fatty foods should be limited as they delay the emptying time of the stomach and take longer to digest. The following are guidelines for the pre-event meal:
It should be eaten 3-4 hours before an event.
The meal should provide 150-350 grams of carbohydrates (1.5 grams per pound of body weight).
To avoid stomach upset, the carbohydrate content of meals should be reduced the closer the meals are to the event.
Adding small amounts of protein can aid in regulating energy levels by slowing down carbohydrate absorption, delivering the carbohydrates to the working muscles at a more consistent rate over time.
Pay attention to salty cravings. If competing in hot/humid climates make sure to replace electrolyte losses with salty snack foods, such as pretzels or sport drinks with added sodium.
Eating at all-day events:
It is important that athletes eat after competing to make sure that they will have enough energy in the muscles for the next race or competition, whether it be in the same day or the following days. The same dietary intake principles used to plan the pre-exercise meal can also apply to foods eaten at all-day events. If an athlete races at 10:00 a.m. and again after two hours, foods that are high in protein and fat will more than likely still be in the stomach potentially causing stomach or gastrointestinal (GI) distress. The following guidelines have been recommended to help athletes make wise food choices at all-day events.
One hour or less between events or heats:
Stick with carbohydrates that are in liquid form, such as juice.
If something solid needs to be eaten, try fruits like oranges, watermelon, cantaloupe, peaches, pears or bananas.
These foods consist of mostly carbohydrates and water. They are digested very fast and therefore, will not cause as much of a problem with stomach cramping or GI distress.
Another key point to making food choices with limited time between events is limiting the quantity of the food eaten. The more an athlete eats, the longer it will take to digest, especially with any pre-competition nerves or stress.
Two to three hours between events or heats:
Solid foods in the form of carbohydrates can be eaten, as there is enough time to digest them before competition.
Try eating bagels, hot or cold cereal with nonfat milk, or english muffins along with fruit like bananas, apples, oranges, peaches, or pears.
Be sure to drink plenty of fluids, like a fluid replacement drink, for hydration, electrolyte replacement, and restoration of glycogen stores.
Four or more hours between events or heats:
With four or more hours between heats or events, an athlete may want a meal, which should be composed primarily of carbohydrates. The following meal examples for this situation are appropriate:
A turkey sandwich on two slices of whole wheat bread, low-fat yogurt with fruit, and a fluid replacement drink; or
Spaghetti with lean meatballs, bread, salad with low-fat dressing, and a fluid replacement drink.
If there is a certain meal pattern before competition that an athlete thinks is a winning combination, then they should stick to it. Athletes who make food choices at concession stands need to know how to make the best choices.
Most concession stands are filled with high-fat, high-calorie foods that are not designed to maximize performance. It is always wiser for athletes to pack a cooler from home with winning combination than to rely on the food at a concession stand.
During exercise:
Consuming carbohydrates during exercise lasting longer than 45 minutes ensures that the muscles require adequate amounts of energy, especially during the later stages of the competition or workout. This has also been found to improve performance. The form of carbohydrates consumed does matter. Some athletes prefer to use a fluid replacement drink, whereas others prefer to eat solid or gel forms of carbohydrates. Use the following guidelines when consuming fluid replacement drinks with carbohydrates:
Choose drinks that have a carbohydrate concentration between 6-8 percent (g/l) these should be consumed in 7-10 fl. oz. amounts every 15-20 minutes Try drinking in gulps not sips.
It is unlikely that a carbohydrate concentration of less than 5 percent is enough to help performance.
Water is needed to aid in absorption of the carbohydrate. Drinks with a concentration greater than 10 percent are often associated with abdominal cramps, nausea, and diarrhea
Note: Fluid replacement drinks should not be confused with “energy” drinks. Energy drinks typically contain one or more stimulants.
After Exercise:
Delaying carbohydrate intake after exercise will hinder muscle glycogen restoration and impair the ability of the muscles to recover. There are several research studies that show that consuming carbohydrates immediately after exercise is beneficial. Other points about post-exercise carbohydrate consumption are that:
Exogenous (ingested) carbohydrate intake promotes the muscles to take up more glycogen, thus refueling the athlete faster. This is important to minimize fatigue associated with repeated days of heavy training, tournament play, or in competition in which several races or games are played over one or more days.
The recommendation is 0.65 grams of carbohydrates per pound of body weight consumed within 30 minutes after exercise. This should be followed by an additional carbohydrate meal two hours later.
The first feeding can be a high carbohydrate beverage, followed by eating a high carbohydrate meal.
A diet rich in carbohydrates increases endurance performance because of the extra store of carbohydrates in the muscles and liver called glycogen. Work completed in the early 1980’s by David Costill at Ball State University showed that if athletes did not consume a diet high in carbohydrates on a daily basis, they would experience chronic fatigue and poor performance. It is well documented that endurance athletes need to replenish carbohydrate stores in the body, especially during periods of intense training. Consuming carbohydrates during workouts lasting over one hour can also benefit performance and delay onset of fatigue. Several recent studies have shown that athletes who participate in stop-and-go sports, such as basketball and soccer, may also need to focus on consuming more carbohydrates. This is not surprising since it is well-known that carbohydrates, when compared to protein and dietary fat, are the most efficiently broken-down and metabolized form of energy for the body. Athletes doing stop-and-go activities were found to have better speeds and to delay fatigue when consuming a higher carbohydrate diet.
Recommended Intake of Carbohydrates
Depending upon the training routine, athletes need to consume at least 50 percent, but ideally 60-70 percent of their total calories from carbohydrates. This percentage is only a guideline for estimating carbohydrate needs. Depending upon the length of training sessions, an athlete’s carbohydrate intake should be between 2.5-6.0 grams per pound of body weight, with longer training times requiring the higher number of grams.
Carbohydrate Intake Before, During, and After Exercise
before exercise:
The pre-exercise or pre-training meal serves two purposes:
It keeps the athlete from feeling hungry before and during exercise
It maintains optimal levels of energy for the exercising muscles.
Carbohydrate intake before exercise can help to restore sub-optimal glycogen stores, which is critical for prolonged periods of exercise. While allowing for personal preferences and psychological factors, the pre-event meal should be high in carbohydrates, non-greasy, and readily digestible. Fatty foods should be limited as they delay the emptying time of the stomach and take longer to digest. The following are guidelines for the pre-event meal:
It should be eaten 3-4 hours before an event.
The meal should provide 150-350 grams of carbohydrates (1.5 grams per pound of body weight).
To avoid stomach upset, the carbohydrate content of meals should be reduced the closer the meals are to the event.
Adding small amounts of protein can aid in regulating energy levels by slowing down carbohydrate absorption, delivering the carbohydrates to the working muscles at a more consistent rate over time.
Pay attention to salty cravings. If competing in hot/humid climates make sure to replace electrolyte losses with salty snack foods, such as pretzels or sport drinks with added sodium.
Eating at all-day events:
It is important that athletes eat after competing to make sure that they will have enough energy in the muscles for the next race or competition, whether it be in the same day or the following days. The same dietary intake principles used to plan the pre-exercise meal can also apply to foods eaten at all-day events. If an athlete races at 10:00 a.m. and again after two hours, foods that are high in protein and fat will more than likely still be in the stomach potentially causing stomach or gastrointestinal (GI) distress. The following guidelines have been recommended to help athletes make wise food choices at all-day events.
One hour or less between events or heats:
Stick with carbohydrates that are in liquid form, such as juice.
If something solid needs to be eaten, try fruits like oranges, watermelon, cantaloupe, peaches, pears or bananas.
These foods consist of mostly carbohydrates and water. They are digested very fast and therefore, will not cause as much of a problem with stomach cramping or GI distress.
Another key point to making food choices with limited time between events is limiting the quantity of the food eaten. The more an athlete eats, the longer it will take to digest, especially with any pre-competition nerves or stress.
Two to three hours between events or heats:
Solid foods in the form of carbohydrates can be eaten, as there is enough time to digest them before competition.
Try eating bagels, hot or cold cereal with nonfat milk, or english muffins along with fruit like bananas, apples, oranges, peaches, or pears.
Be sure to drink plenty of fluids, like a fluid replacement drink, for hydration, electrolyte replacement, and restoration of glycogen stores.
Four or more hours between events or heats:
With four or more hours between heats or events, an athlete may want a meal, which should be composed primarily of carbohydrates. The following meal examples for this situation are appropriate:
A turkey sandwich on two slices of whole wheat bread, low-fat yogurt with fruit, and a fluid replacement drink; or
Spaghetti with lean meatballs, bread, salad with low-fat dressing, and a fluid replacement drink.
If there is a certain meal pattern before competition that an athlete thinks is a winning combination, then they should stick to it. Athletes who make food choices at concession stands need to know how to make the best choices.
Most concession stands are filled with high-fat, high-calorie foods that are not designed to maximize performance. It is always wiser for athletes to pack a cooler from home with winning combination than to rely on the food at a concession stand.
During exercise:
Consuming carbohydrates during exercise lasting longer than 45 minutes ensures that the muscles require adequate amounts of energy, especially during the later stages of the competition or workout. This has also been found to improve performance. The form of carbohydrates consumed does matter. Some athletes prefer to use a fluid replacement drink, whereas others prefer to eat solid or gel forms of carbohydrates. Use the following guidelines when consuming fluid replacement drinks with carbohydrates:
Choose drinks that have a carbohydrate concentration between 6-8 percent (g/l) these should be consumed in 7-10 fl. oz. amounts every 15-20 minutes Try drinking in gulps not sips.
It is unlikely that a carbohydrate concentration of less than 5 percent is enough to help performance.
Water is needed to aid in absorption of the carbohydrate. Drinks with a concentration greater than 10 percent are often associated with abdominal cramps, nausea, and diarrhea
Note: Fluid replacement drinks should not be confused with “energy” drinks. Energy drinks typically contain one or more stimulants.
After Exercise:
Delaying carbohydrate intake after exercise will hinder muscle glycogen restoration and impair the ability of the muscles to recover. There are several research studies that show that consuming carbohydrates immediately after exercise is beneficial. Other points about post-exercise carbohydrate consumption are that:
Exogenous (ingested) carbohydrate intake promotes the muscles to take up more glycogen, thus refueling the athlete faster. This is important to minimize fatigue associated with repeated days of heavy training, tournament play, or in competition in which several races or games are played over one or more days.
The recommendation is 0.65 grams of carbohydrates per pound of body weight consumed within 30 minutes after exercise. This should be followed by an additional carbohydrate meal two hours later.
The first feeding can be a high carbohydrate beverage, followed by eating a high carbohydrate meal.
