Recommended Guidelines on the Prevention of Dehydration

This purpose of this document is to provide student athletes with important information regarding the prevention and detection of dehydration. It is not meant to replace or precede a medical evaluation by a physician, athletic trainer, or other health care professional.

ü To ensure proper pre-exercise hydration, consume approximately 17 to 20 fl oz of water or a sports drink 2 to 3 hours before exercise 7 to 10 fl oz of water or a sports drink 10 to 20 minutes before exercise.

ü Fluid replacement should approximate sweat and urine losses and at least maintain hydration at less than 2% body weight reduction. This generally requires 7 to 10 fl oz every 10 to 20 minutes.

ü Dangerous hyper-hydration is also a risk if an athlete hydrates based on published recommendations and not according to individual needs.

ü A cool beverage of 10° to 15°C (50° to 59°F) is recommended.

ü An ingestion rate of about 1 g/min (0.04 oz/min) maintains optimal carbohydrate metabolism: for example, 1 L of a 6% carbohydrate (CHO) (i.e. Gatorade) drink per 1 hour of exercise.

ü In many situations, you as an athlete benefit from including carbohydrates (CHO’s) in your re-hydration protocol. Consuming CHO’s during the pre-exercise hydration session (2 to 3 hours pre-exercise), along with a normal daily diet, increases glycogen stores.

ü CHO concentrations greater than 8% increase the rate of CHO delivery to the body BUT compromise the rate of fluid emptying from the stomach and absorbed from the intestine.

§ Therefore fruit juices, CHO gels, sodas, and some sports drinks have CHO concentrations greater than 8% and are not recommended during an exercise session as the sole beverage.

ü Athletes should consume CHO’s at least 30 minutes before the normal onset of fatigue and earlier if the environmental conditions are unusually extreme.

ü A practical way to measure sweat loss is to weigh yourself immediately prior to and finishing an exercise session. The resulting difference in body weight should not exceed 2% of the pre-exercise weight.

ü Your post-exercise hydration should aim to correct any fluid loss accumulated during the practice or event. This is measured by pre and post exercise body weight values.

ü Ideally completed within 2 hours, re-hydration should contain water to restore hydration status, carbohydrates to replenish glycogen stores, and electrolytes to speed re-hydration.

ü Most CHO forms (i.e., glucose, sucrose, glucose polymers) are suitable, and the absorption rate is maximized when multiple forms are consumed simultaneously.

ü Substances to be limited include fructose (which may cause gastrointestinal distress); those to be avoided include caffeine, alcohol (which may increase urine output and reduce fluid retention), and carbonated beverages (which may reduce voluntary fluid intake due to stomach fullness).

Athletes should be able to recognize the basic signs and symptoms of dehydration: thirst, irritability, and general discomfort, followed by headache, weakness, dizziness, cramps, chills, vomiting, nausea, head or neck heat sensations, and decreased performance

Mild

Thirst
Dry Lips
Slightly dry mouth

Membranes

Moderate

Very dry mouth membranes
Sunken Eyes
Skin doesn’t bounce back quickly when pinched and released /

Severe

All signs of moderate dehydration
Rapid weak pulse
(>100 at rest)
Cold hands and feet
Rapid breathing
Blue lips
Confusion, lethargy, difficult to arouse

Athletes should begin all exercise sessions well hydrated. Athletes can approximate the hydration status in several ways. The simplest method is comparison of urine color (from a sample in a container) with a urine color chart.

References

Casa, D. J., Armstrong, L.E., Hillman, S.K., Montain S.J., Reiff, R.V. (2000). National Athletic Trainers’ Association Position Statement:Fluid Replacement for Athletes. Journal of Athletic Training; 35(2):212–224.