Healthy eating habits/Hydration for Adolescent Athletes

Why it is important to stay hydrated for sport performance?

Hydration is important in sports performance. Dehydration is when the body loses an excess of body fluids. This can have many negative effects on performance. It has been shown that as little as a 2% fluid loss can negatively affect strength, endurance and stamina. It is important to develop a hydration plan (before, during and after) in order to maintain hydration and so athletes can perform better.

Signs of dehydration

Thirst

Dry mouth

Headache

Constipation

Dizziness

Muscle cramps

Impaired memory and concentration

Fatigue

The above is a list of signs of dehydration. Another indicator is dark yellow urine. If the colour of urine is dark prior to training it can greatly affect the ability to perform well.

How much water does an adolescent need?

How much water is needed per day?

Age	Males	Females
9-13	1.6L/day = 8 glasses	1.4L/day = 7 glasses
14-18	1.9L/day = 9.5 glasses	1.6Lday = 8 glasses

1 glass = 200ml

There is no one prescription when it comes to meeting fluid needs during exercise. Athletes are able to estimate their own fluid needs by weighing themselves before and after exercise. For every kilogram lost this equals 1 litre of fluid loss. This amount will vary for each individual based on body size, genetics and environment. It is important to know an athletes sweat rate as a hydration plan can be prepared. Athletes need to practice how much fluid they can tolerate during games and training, the Australian Institute of Sport suggest 200-300ml every 15-20 minutes.

Water

Water is always the best choice to maintain hydration throughout the day. Checking urine colour is a good indication as to whether an athlete needs to drink more water. Water is also inexpensive and does not contain extra energy that can cause weight gain. It is suggested to drink water if activity levels are less than 1 hour in duration.

Sports drinks

Sports drinks are also a good choice if a sporting event e.g. a basketball game is greater than 1 hour or if it is a hot humid day. Sports drinks provide water and electrolytes as well as glucose. The Australian Institute of Sport recommends that sport drinks contain 4-8% carbohydrate and 10-20 mmol/L sodium. It is important to consider that sports drinks do contain sugar so excessive amounts can increase the risk of dental caries.

Chocolate milk

Chocolate milk is a relatively new suggestion as an alternative to sports drinks. It contains water as well as glucose to help replenish muscle glycogen. It also has a similar electrolyte profile to sports drinks and also contains calcium which can be of benefit for growing adolescents. It may not be ideal to drink chocolate milk during games, however as a post game drink it can be a good alternative.

Others

Other drinks such as cordials, fruit juices and vitamin waters are not ideal drinks for hydration. This is because they usually contain more than 10% carbohydrate.

Hydration strategies for sports performance

1. Ensure that you are well hydrated BEFORE starting training/playing a game.
2. Continue to drink during training/playing a game at 200-300ml every 10-20 minutes.
3. Have a clear water bottle with 100ml markings so athletes can monitor their fluid intakes during sport.
4. Know your sweat rate.
5. Include a sports drink/chocolate milk AFTER training to replace glycogen and electrolyte losses if activity has been > 60 minutes, activity is intense or it is a hot day.

References

1. Sports Dietitians Australia [SDA], (2009). Eating and Drinking before Sport - Fact Sheet. Available at: http://www.sportsdietitians.com.au/resources/upload/Eating_Drinking_Before_Sport.pdf, Accessed: October, 2013

2. Sports Dietitians Australia [SDA]. Fluids in sport. Available at: http://www.sportsdietitians.com.au/content/2546/FluidsinSport/, Accessed: October, 2013

3. Australian Sports Commission (2009) Fluid, Who needs it? - Australian Institute of Sport. Retrieved: http://www.ausport.gov.au/ais/nutrition/factsheets/hydration/fluid_-_who_needs_it, Accessed on: October, 2013

4. Australian Sports Commission (2009) Fluid Facts for Basketball - Australian Institute of Sport. Retrieved: http://www.ausport.gov.au/ais/nutrition/factsheets/hydration/fluid_facts_for_basketball, Accessed on: October, 2013