A few thoughts on Hydration for your athletes

I wanted to make some points about hydration so you have some scientific reasoning as to the why your youth athlete should be drinking water every day.

First, water is the largest component of our bodies, accounting for about 45-75% of our total body weight.  Second, water acts as a lubricant, shock absorber, and solvent.  Maintaining a positive fluid balance aids in nutrient transport, which means getting the converted sugars from food to the right places for when we are training and recovering.  Third, it is essential for the body’s temperature regulation; during training we lose water through sweat which helps keeps our skin cool once we reach a certain threshold.  Post training your youth athlete should be hydrating 150% of what he/she sweats out; we don’t have the tools at our facility to objectively measure what the athletes loses pertaining to sodium and nitrogen during a single training bout.  However, if your youth athlete is unable to complete their training for the day, this may be caused by dehydration.  What can happen is (if not taking in fluids) they may exceed his/her hydration status, which means once he/she starts to sweat from training, he/she may be sweating out more than what is available for that function. 

A couple things about dehydration, adolescents and kids are at greater risk of dehydration than adults are resulting from an increase in gaining heat from the environment because of the greater surface ratio compared to adults.  Increased heat production during training, a decreased ability to dissipate heat through sweat, and a decreased sense of thirst compared to adults. This all can lead to a decrease in athletic performance, increasing fatigue; can lead to a decrease in motivation in some cases, decrease in neuromuscular control, accuracy, muscular strength, muscular endurance, and overall general performance.  Dehydration can increase the core body temp, reduce stroke volume (the amount of blood pumped per beat), cardiac output, decrease in blood pressure, reduction in blood flow (thickening of the blood), increase in heart rate, increase the risk of heat stroke, and rhabdomyolysis (which is very dangerous). 

What I can recommend for your youth athlete is that they drink water daily to satisfy their body being in a hydrated state every day.  Signs they can monitor for themselves is what color their urine is when they goes to the bathroom. If dark yellow, he/she should drink 12oz of water ASAP.  A lighter the color is a good indication of chronic hydration.  What may skew their assessment of hydration can be consuming beets, blackberries, B vitamins, and certain medications may turn the urine dark yellow, bright yellow, pink, red, or orange. 

A quick way to estimate hydration status can be having your youth athlete weigh in at the begin training, and again concluding training.  Preferably with minimal clothes on to get an objective estimate of his/her bodyweight.  An example of this can be without a shirt, or shoes.  This is something he/she can do on their own, privately in a bathroom here at our facility, and recording his/her weight on the daily workout card.  Additionally, tracking bodyweight over time can assess changes over time which may help to identify chronic dehydration.  For example, losing several pounds over the course of a few days. 

To wrap this up, your youth athlete should be aiming to avoid losing more than 2% of their bodyweight at the conclusion of every training bout, and hydrating during training.  He/she should be prehydrating before training to allow for fluids to be absorbed, and post training replacing fluid and electrolyte (sodium, potassium, chlorine) loses, by way of drinking water and post workout meals (protein, and carbs).  For an aggressive approach, if dehydrated, he/she can consume 1.5L of fluid per kilo (1lbs = 2.2KG) of bodyweight lost immediately.

Recommendations for youth athletes   

Four hours before event (training session, or athletic event): 

• Consume appx 5-7ml (0.16-0.23oz) water or sports drink per KG bodyweight
• Example, if he weighs 100lb, that’s 45kg x 0.19 = 8.56oz of fluids

Two hours before event recommendations:

• If not adequately hydrated, sip on 3-5ml (0.1-0.17oz) of fluid per KG bodyweight

During event recommendations:

• Adolescents weighting 60KG (132lb) should drink 9oz every 20 minutes even if they don’t feel thirsty 

Influence of graded dehydration on hyperthermia and cardiovascular drift during exercise
S. J. Montain and E. F. Coyle
Journal of Applied Physiology 1992 73:4, 1340-1350