Adequate hydration for all sports has an impact on performance and hydration demands for swimmers are no exception. There is limited data on the effects of dehydration and performance in young athletes. Parents and coaches stress the need for their young athletes to stay hydrated, but having clear cut guidelines on how to do that and what to look for need to be established, otherwise the advice means nothing.
The American Academy of Pediatrics position stand on hydration and activity indicates that replenishment with 100-250 ml (3-8 ounces) of fluid every 20 minutes for 9-12-year olds and 1.0-1.5L per hour of activity for older children can help ward off dehydration, assuming the child is hydrated prior to activity.
Swimmers are in a unique circumstance because rarely does practice mimic competition. Practice times can be long, while competition races are short, most often 50 to 100 meter races for swimmers 12 and under and 100 to 200-meter swims for adolescents over 13 years of age. In addition, depending on location, adolescent swimmers may be practicing in the outdoors or indoors, so hydration plans can vary.
The physiology of how a swimmer might become dehydrated is one of concern, because a swimmer may find it difficult to recognize. During water immersion, anti-diuretic hormone (ADH) is suppressed. This is opposite of endurance sports, where ADH would increase to maintain fluid balance in the body. Basically, ADH is what keeps you from urinating and when this is suppressed, you might feel the need to urinate. This is also why we often see children exiting the pool to use the restroom.
Water immersion may also suppress thirst, making it difficult to increase fluid intake during practice.
Dehydration may be more of an issue for adolescents with morning practice or early morning warm ups for competition. Research published in the Journal of Strength and Conditioning Research found that 67% of swimmers came to morning practice dehydrated, but were able to hydrate throughout practice drinking as needed and maintained fluid balance.
Allowing and encouraging personal water bottles on the pool deck and taking regular water breaks, can help rehydrate swimmers, especially those in morning practice.
Swimmers will still sweat in the water, but they may have an advantage to dissipate heat better than athletes in land sports. Knowledge on hydration is important to keep swimmers hydrated throughout practice and competition.
Weighing before and after exercise is still the best indicator of water loss during activity. While this is not always reasonable for children, it is an effective method to see if they are losing large amounts of water weight during practice. Replenish with 16 ounces of water (2 cups) for every pound lost.
In addition, many young athletes know to pay attention to urine color – light yellow (lemonade) is an indicator that they are hydrated, but darker yellow (apple juice) means they are way behind on drinking fluids.
For swimming at low intensity and at meets, water is the best choice for hydration. At higher intensities or for swim programs utilizing ultra short race pace training (USRPT) or high intensity training (HIT), for exercise longer than 60 minutes, and for those in hot and humid environments, drinks with electrolyte replenishment may be warranted.
If your child is tired of water and you feel that something else would be helpful, milk or 100% fruit juice are options that can provide fluid as well. Mixing fruit juice with water is a good option for children who need a little flavor to their drinks.
Another way to get more fluid in your athletes is to fuel them with fruits and vegetables with high water content. This is a great alternative for water during meets when they need to fuel with carbohydrates and fluid at the same time, but don’t want too much in their stomach. Grapes, strawberries, watermelon, oranges, and cucumbers are all good options.
References:
Adams, J. D., Kavouras, S. A. Robillard, J. I., Bardis, C. N., Johnson, E. C., Ganio, M. S., McDermott, B. P., & White, M. A. (2016). Fluid balance of adolescent swimmers during training. Journal of Strength and Conditioning Research, 30(3), 621-625