Baseball

Baseball is a wonderful sport that requires an almost equal combination of teamwork and individual effort. It's also a highly mental game, requiring that the athlete stay constantly alert to make split-second judgments for the right play. It's safe to say that physically tired baseball players are also likely to be mentally tired (glucose is the fuel for both the brain and muscles) and prone to bad judgment and poor physical performance. David Halberstam, in his book Summer of '49 (New York: William Morrow, 1989), describes the 1949 pennant race between the Red Sox and Yankees. A central theme of this book is how players get worn out during the long baseball season, with the outcome of the pennant race determined, to a degree, by the number of players who remain relatively fresh by the end of the year. Clearly, many factors contribute to wear players down during a long season, including frequent travel, hard-fought games, and constant time-zone changes.2 Nutrition factors also come into play: The foods and fluids consumed over the long summer and fall season do make a difference in the outcome. When steak and beer are constantly on the menu, as was common for many baseball players in the past, it is predictable that physical and mental fatigue will eventually take its toll. Alcohol interferes with B-vitamin metabolism (and therefore energy metabolism) and also increases dehydration risk. Red meat is a useful means of supplying good-quality protein, iron, and zinc, but it should not be the focus of a baseball player's diet. What baseball players really need is plenty of bread, cereal, fruits, and vegetables to constantly replace the glycogen used up in the quick and powerful actions of the game, as well as enough calories to support their muscle mass. Keeping this in mind, baseball players must consider the following nutritionally relevant factors for their sport.

As a primarily summer sport, baseball is often played in a hot and humid environment. Optimally hydrated muscles are composed of more than 70 percent water, and it should be the athlete's goal to maintain this optimal hydration state. A failure to do so will lead to a progressive reduction in total body water with a concomitant reduction in athletic performance. Evidence suggests that poor hydration makes an athlete more prone to injury by reducing mental function (poor hydration is associated with higher core temperatures that can reduce coordination) and by making muscles less resilient (thus increasing the risk of muscle tears and pulls).

Baseball players (particularly pitchers) are known to experience a reduction in peak torque arm strength between pre- and postseason measurements, with some of this power reduction caused by overuse injury to the pitching arm.³ Reduced throwing power could also be due to reduced leg strength, which could negatively alter the throwing motion and exacerbate the risk of injury.⁴ It seems likely that the degree to which the progressive reduction in power occurs could be reduced with a regular program of optimized hydration and energy intake.⁵

A study of baseball players strongly suggests that conditioning plays an important role in the ability of the athletes to maintain an optimal hydration state. At fixed exercise intensities, the better-conditioned baseball players were able to maintain body temperature with a lower sweat rate than that of players who were less fit.⁶ Another study found that blood flow to the pitching arm (in pitchers) increased up to 40 pitches but steadily declined after that. By the 100th pitch, blood flow to the pitching arm was 30 percent below baseline.⁷ The decrease in blood flow to the pitching arm matches a decrease in the general hydration state of the pitchers. Since it is established that blood volume is a key factor in the maintenance of athletic performance, the performance of pitchers may be strongly influenced by their ability to stay hydrated.

Given the possibility of frequent exposure to hot and humid environments, baseball players should consider the following strategy for maintaining their hydration state:

1. During the preseason, weigh yourself before and after each game and practice to learn how much weight has been lost. Then determine how much fluid should be consumed during a typical game (1 pint of fluid equals 1 pound of body weight). The goal should be to drink enough fluids to maintain body weight (±1 pound) during the game. Different people have different sweat rates, so your drinking schedule is likely to be different from those of your teammates.
2. Drink plenty of fluids before each game (a minimum of 16 ounces 1 hour before the game, followed by a constant sipping of fluids).
3. Use each opportunity between innings to consume fluids. Since baseball involves multiple bouts of high-intensity movements, the drain on stored glycogen is high. Therefore, fluids consumed should be carbohydrate containing. Fluids containing a 6 to 7 percent carbohydrate solution are best both for replacing carbohydrate and for encouraging a fast fluid absorption.
4. Immediately after the game, eat and drink enough carbohydrate to reconstitute your glycogen stores and body water.
5. Avoid or limit the consumption of alcohol and caffeinated beverages. With sufficient intake, both alcohol and caffeine have a diuretic effect that could place an athlete in a negative water balance.

Baseball requires a combination of power and speed, both of which place a high reliance on phosphocreatine and carbohydrate (primarily glycogen) for muscular fuel. Phosphocreatine is synthesized from three amino acids (from protein), so an adequate intake of protein is necessary to ensure that sufficient phosphocreatine can be manufactured. However, the protein consumption must be in the context of an adequate total intake of energy (calories). It is easier for fully grown baseball players to obtain sufficient energy (baseball players reach their peak at around age 28).⁸ However, younger players must supply enough energy to support the activity plus enough energy to support growth. Inadequate energy intake causes the consumed protein to be burned as a fuel, making it unavailable for use as a substrate for the manufacture of other substances, such as creatine. With sufficient energy, even a modest protein intake of between 1.2 and 1.7 grams per kilogram is sufficient to support the synthesis of creatine and support a stable or growing muscle mass. In the context of an adequate energy intake, baseball players should consume a diet that derives 60 to 65 percent of its energy from carbohydrate, 20 to 25 percent of its energy from fat, and 15 percent of its energy from protein.

Many games are played during the season, with several games played each week. This frequency of games and practices can easily lead to overtraining, with the associated problems of fatigue, weakness, and increased risk of illness. A key to limiting the impact of overtraining is adequate rest and the consumption of a high-carbohydrate diet to maintain muscle glycogen levels. It has been shown that daily practices or competitions will lead to a progressive reduction in muscle glycogen storage, with a related reduction in endurance and performance. Since baseball players are highly dependent on muscle glycogen as a fuel, a reduction in glycogen from inadequate carbo hydrate intake would lead to a discernable lowering of performance with time.

Games typically last 2 to 3 hours. Normal blood glucose flux is approximately 3 hours. That is, from the time you finish eating a meal, blood glucose stays in the normal range for about 3 hours. After this, blood glucose falls below the normal range (80 to 120 milligrams per deciliter), a physiological event normally associated with hunger. In the exercising person, blood glucose is likely to fall below the normal range more quickly. Because blood glucose is an important factor in maintaining normal mental function, and is also important for delivering fuel to muscles that have exhausted stored carbohydrate, baseball players should take steps to maintain blood glucose during the entire game by consuming a carbohydrate-rich beverage at every opportunity.

Pitchers work harder when pitching than other players on the team, which is why they are able to pitch effectively only every three to five games. Pitchers are better able to maintain muscular power (both in the legs and arms) by maximizing glycogen storage and hydration state before and during each game. The principle of glycogen loading (a general tapering of activity coupled with a high carbohydrate and fluid intake information) can be followed with starting pitchers because they typically have several days between starts.

The weight and insulating effect of the equipment worn by catchers adds to their energy and fluid requirements. Catchers are constantly in motion, working with the pitcher, and since they tend to play on a more frequent rotation than starting pitchers, it's safe to say that, pound for pound, catchers have the highest energy and fluid requirements of any of the baseball positions.