How Important is Hydration for an Athlete?

Water, otherwise known as H20, consists of two hydrogen atoms and one oxygen atom. It is simply the medium used for transporting the body’s nutrients and minerals, as well as the place where the body’s biochemical reactions occur. “Depending on a person’s body fat content, water’s content can vary about 45% in very obese individuals to 70% in very lean individuals.” Needless to say, water is life, life is water.2) How much attention should I pay to water, as an athlete? Should I be precise on how much I intake, and if so when should I injest  certain amounts? What will happen if I become lax, as an athlete, with my water? Athletes aren’t the only ones who should be paying attention to these questions. Every living person needs water to survive.

Dehydration and its Negative Effects on Exercise

Dehydration does affect performance. “When water losses reach 1-4% of your body weight, reduction in physical performance will occur. Marathon runners can lose several quarts of water during a race, which represents 6-10% of their body weight.” 2)  Even more anaerobic oriented sports, such as soccer and hockey, can experience such losses. With this being said, the thirst response in humans is not as fine tuned as it should be, and won’t experience the thirst feeling until hours later. So you have to be constantly on top of it.

Proper Fluid Replacement to Maintain Athletic Performance

Ensuring adequate hydration includes initiating exercise in a euhydrated state and matching fluid intake to sweat rate during exercise. 4) Fluid replacement should approximate sweat and urine losses and at least maintain hydration at less than 2 percent body weight reduction. This generally requires 200 to 300 mL (7 to 10 fl oz) every 10 to 20 minutes during exercise.5) Proper hydration during exercise will influence cardiovascular function, thermoregulatory function, muscle functioning, fluid volume status, and exercise performance.  The goal of drinking during exercise is to prevent excessive dehydration (2 percent body weight loss from water deficit) and excessive changes in electrolyte balance to avert compromised exercise performance.5) Fluid ingestion may also influence performance by delaying the evolution of core temperature by acting as a “heat sink.” An increased central drive and motivation may also be experienced by being well hydrated.

Some, but not all, exercise is going to be affected by being hydrated or dehydrated. Athletes involved in shorter anaerobic exercises have less physiologic changes occurring and therefore can experience an increase in performance due to less body mass by being slightly hypohydrated. Longer, more aerobic exercises use more total body water and therefore need to be replenished during exercise. Replenishing the water stores will influence several factors and keep the athlete hydrated enough to perform at his or her best capabilities.

References

1. Casa, Douglas J., Armstrong, Lawrence E., Hillman, Susan K., Montain, Scott J. (2000). National Athletic

Trainers’ Association Position Statement: Fluid replacement for athletes. Journal of Athletic Training, 35(2), 212-224.

2. Gastelu, D., & Hatfield, F. (2013). Water and Oxygen. In Sports Nutrition (3rd ed., pp. 76-79). Carpinteria, Ca:

International Sports Sciences Association.

3. Godek, Sandra Fowkes., Bartolozzi, Arthur R., Burkholder, Richard, Sugarman, Eric, & Dorshimer, Gary.

(2006). Core temperature and percentage of dehydration in professional Linemen and backs during preseason practice. Journal of Athletic Training, 41(1)8-17.

4. Osterberg, Kristin L., Horswill, Craig A., & Baker, Lindsay B. (2009). Pregame urine specific gravity and fluid

intake by National Basketball Association players during competition. Journal of Athletic Training, 44(1), 53-57.

5. Sawka, Michael N., Burke, Louise M. (2007). Exercise and fluid replacement. American   College of Sports

Medicine. www.acsm.org.