Pre-contest / Contest Day Preparation

[Bigun]

Pre-contest / Contest Day Preparation - Gastric Emptying and Fluid Delivery to Working Muscles

Several factors influence the rate at which fluids leave the stomach. Gastric emptying describes the volume of food or drink that leaves the stomach per unit of time. Food or drinks with a slower gastric emptying take longer to completely leave the stomach. This means that these substances enter the small intestine more slowly, and some of the food or drink will remain in the stomach longer.

Carbohydrate Concentration of the Solution

Sports beverages and other beverages consumed by athletes commonly contain carbohydrate. When the concentration of carbohydrate in a fluid rises above 7 percent, gastric emptying time decreases. At concentrations below 7 percent carbohydrate, gastric emptying time is not significantly affected, showing gastric emptying characteristics similar to water.

For this reason, the recommended carbohydrate concentration in sports beverages is below 8 percent. Having said that, some ultra-endurance athletes "train" their stomachs to tolerate greater concentrations because they desperately need the additional carbohydrate.

Type of Carbohydrate in the Solution

Carbohydrates are not all the same, coming in different molecular sizes and in different molecular combinations. For instance, glucose19 is a monosaccharide (a single-molecule carbohydrate), sucrose is a disaccharide (two monosaccharides held together with a bond), and starch is a polysaccharide (many molecules of monosaccharides held together with bonds).

The smaller the length of a carbohydrate chain, the slower the gastric emptying time. Therefore, on an isocaloric basis, pure glucose (a monosaccharide) will take longer to leave the stomach than table sugar (a disaccharide), and table sugar will take longer to leave the stomach than a simple starch (a polysaccharide).

Amount of Fluid Consumed

The amount of fluid consumed at one time has a major influence on gastric emptying time. When a large volume of fluid is consumed, gastric emptying time is initially faster, and when the volume of fluid in the stomach is reduced, gastric emptying time slows. To achieve a hydrated state before competition or practice, 14 to 22 ounces (420 to 660 milliliters) of fluid should be consumed, followed by frequent sipping on fluid to maintain fluid volume in the stomach and, therefore, a faster gastric emptying time.

Temperature of the Solution

Beverage temperature only slightly affects gastric emptying time. When people are at rest, fluids at body temperature leave the stomach more quickly than either very hot or very cold fluids. During exercise, however, it appears as if cool fluids leave the stomach more quickly than room-temperature or body-temperature fluids. An important consideration, although not affecting gastric emptying, is that athletes may consume more cool fluids.

Carbonation of the Solution

Athletes commonly believe that consuming a carbonated beverage causes gastric distress and delayed gastric emptying, but there is little scientific evidence that this occurs. However, studies evaluating the impact of fluid carbonation on gastric emptying time have typically relied on few subjects.

In general, the studies suggest that, all other things being equal (carbohydrate concentration, volume, temperature, and so on), carbonation has little impact on gastric emptying. Nevertheless, carbonation does make athletes feel more full, thereby reducing the drive to drink. Nothing should take away the athletes' drive to drink because this can negatively affect hydration state.

Relative Hydration State of the Athlete

Progressive dehydration and higher body temperatures associated with high-intensity activity cause a slower gastric emptying rate. This is an excellent rationale for athletes to maintain hydration state during activity. Dehydration will make it almost impossible for the athlete to return to an adequately hydrated state during exercise, and if this is attempted through consumption of a large volume of fluid, it will likely lead to a sense of discomfort rather than faster rehydration.

Degree of Mental Stress

The mental stress and anxiety associated with athletic competition is a major factor in gastric emptying. Higher levels of mental stress and anxiety are associated with a reduced gastric emptying that can have a serious impact on the ability to adequately rehydrate during competition. The mental training techniques that can be learned from a sports psychologist to reduce stress are important for reducing the physiological effects of sports-related stress and anxiety.

Type of Physical Activity

High-intensity activity is associated with a slower gastric emptying rate than lower-intensity activity, but the differences are minor. Additionally, the type of activity (running, swimming, cycling) does not appear to have a large influence on gastric emptying rate.

[Narkissos]

This article isn't relevant to this section.

-N

[Bigun]

How come Nark?

[Narkissos]

^^Isn't this the 'pro-bodybuilding' forum?

This article is relevant to sports other than bodybuilding contest preps... namely endurance sports.. which bodybuilding is not.


-CNS

[Bigun]

Ok well I beg to differ as this was the info I gave and researched with a recently turned pro bodybuilder in the UK but I respect your opinion as your a competitor and I am not