Football is a sport that involves 5-10 second bursts of high-intensity movement followed by long breaks between offensive and defensive plays. Whether the athlete is blocking to protect the quarterback or sprinting down the field, the primary energy source the athlete is using is carbohydrate, specifically the sugar called glucose. Anytime a person eats carbohydrate, the body breaks it down into glucose (which is often referred to as blood sugar), but this process can take a long time depending on the original source of carbohydrate (e.g. whole wheat pasta vs. sports drink)(1). In order to quickly fuel your players, carbohydrates that are easily digested and absorbed are important nutrients to consume immediately before and during practices and games (2). Sports drinks and other sports products are designed with ingredients such as glucose, sucrose and/or maltodextrin in order to support the immediate fueling needs of athletes (3).

Success as a football player depends on the ability of the athlete to perform football-specific skills and cognitive tasks over the entire course of the game. Eating or drinking sources of carbohydrate during practices lasting more than 60 minutes and games may help support your athlete's performance and decision-making (2). While few research studies have been conducted on American Football players specifically, data from similar team sports can be extrapolated to the demands of American Football.

1. Spare muscle glycogen

Athletes can store a limited amount of energy in the form of glycogen (stored glucose) in the muscle and liver. High intensity or powerful bursts of energy such as sprints or tackling can burn through these stores fairly quickly (4). Reduced glycogen levels in the muscle after prolonged activity, especially towards the end of a practice or game, have been associated with impaired performance (5,6). Taking in quickly-used carbohydrates (glucose, sucrose or maltrodextrin) at a rate of 30-60 g/h provides the body with a source of fuel, allowing it to preserve muscle glycogen for the latter stages of the game (2).

2. Maintain blood sugar

Blood sugar in healthy individuals is very tightly regulated by the body (9); however, under certain circumstances even a healthy athlete can succumb to low blood sugar. If the athlete is unable to consume a carbohydrate-rich pre-game meal or snack and he has exhausted his liver glycogen stores, blood sugar can fall below normal levels (1). Symptoms of low blood sugar include fatigue, dizziness, confusion, mood swings and rapid heartbeat (1). These symptoms can all impact play on the field.

Eating or drinking carbohydrate during practices and games increases blood glucose concentrations, preserving liver glycogen and providing fuel for the working muscles and brain (3, 10).

3. Fuel for the brain

The primary source of fuel for the human brain, whether at rest or during activity, is glucose (1,2). It is critical to have adequate fuel to support blood glucose and liver glycogen, to ensure that the brain will have fuel to use for energy.

Some studies have shown that carbohydrate intake can even help with cognitive function. Without adequate fuel available for the brain, performance indicators such as reaction time and decision-making skills may be impaired (7).

One study demonstrated that the impact of carbohydrate on the brain actually starts in the mouth. The presence of carbohydrate (sweetness does not matter) in the mouth improved high-intensity short duration performance by stimulating the centers of the brain associated with fatigue, pleasure and/or motor control (11). This is an interesting concept because it means that carbohydrate may benefit the player before it is even swallowed.

Taking in carbohydrate, in the form of sugar, immediately before and during practices and games can support your athlete's overall performance on the field.

Provided by Gatorade Sports Science Institute

Lisa Heaton is a sports dietitian at the Gatorade Sports Science Institute and serves as the sports dietitian for the Chicago Bulls.

References

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Bendiksen M, Bischoff R, Randers MB et al. The Copenhagen Soccer Test: physiological response and fatigue development. Medicine and science in sports and exercise. 2012;44(8):1595-603.

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Ali A, Williams C. Carbohydrate ingestion and soccer skill performance during prolonged intermittent exercise. Journal of sports sciences. 2009;27(14):1499-508.

Winnick J, Davis J, Welsh R, Carmichael M. Carbohydrate feedings during team sport exercise perserve physical and CNS function. Medicine and science in sports and exercise. 2005;37:306-315.

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Krustrup P, Mohr M, Steensberg A, Bencke J, Kjaer M, Bangsbo J. Muscle and blood metabolites during a soccer game: implications for sprint performance. Medicine and science in sports and exercise. 2006;38(6):1165-74.

Nybo L. CNS fatigue and prolonged exercise: effect of glucose supplementation. Medicine and science in sports and exercise. 2003;35(4):589-94.

Jeukendrup AE, Chambers ES. Oral carbohydrate sensing and exercise performance. Current opinions in clinical nutrition and metabolism care. 2010;13:447-451.