Hydration

Adam Depmore
Oct 19, 2018

When it comes to hydration, no drink can compare to water. It is vital to our existence and our ability to perform. Water itself is the ultimate hydrator, and while many drink companies will try to provide you with a list of potable alternatives to water, many of these  "hydration hacks" cannot  actually be proven. Nothing beats water au naturale.

Think about this, your body is made up of 60-70% water. When you are training, you sweat and loose that water in order to keep yourself cool. Even in our fabulous, covered indoor pool, your body is constantly sweating during practice.nSeveral studies have indicated that during aerobic performance, such as swimming, performance begins to decrease when dehydration progressively exceeds 2-3 percent body weight loss.  That may sound like a lot, consider this: a modest 3% level of dehydration causes a muscle to lose 10% of its contractile strength and 8% of its speed. Weak muscles = poor performance. 

Research through the Nationals Strength and Conditioning Association (NSCA) and the American College of Sports Medicine have shown that the thirst sensation doesn't really kick in until you're already dehydrated. So if it helps, think of it this way: If you're thirsty, your performance may already be affected. Let’s take a further look.

Negative Effects of Dehydration: Scientific tests of athletes suffering 5% dehydration show up to a 30% decline in standard performance, and these results were measured during events lasting 35 minutes or less. Ever competed in a race over 35 min? 

Longer efforts would show more dramatic results: 3-5 hours of exercise without hydration causes the heart rate for a fixed level of output to increase by 30 beats per minute (BPM), while stroke volume decreases. 

The body controls its temperature through sweat. At rest, evaporation through the skin is responsible for roughly 30% of water loss, but during heavy, exercise-induced sweating can increase almost 300 times (depending on air temperature, humidity, and body surface area - a bigger athlete loses more).

You cannot keep up with this dramatic volume of fluid loss without intense vigilance and self-discipline and practice. Dehydration reduces blood volume and increases the viscosity of the blood. Several problems ensue:

  1. Decreased flow of oxygen (via red blood cells) and nutrients to the muscles
  2. Decreased efficiency in removal of CO2 and acid by the blood
  3. Decreased aerobic efficiency
  4. Impaired circulation to the extremities that could result in cold-related injuries 
  5. Increased heart rate
  6. Loss of strength and speed

Symptoms of dehydration include muscle cramping (may also be due to sodium deficiency), excessive fatigue, and shortness of breath. Eventually vomiting, hot, dry, skin, a coma and so on but you will have fallen off or become “stretcher-material” long before you reach this point.

Water Requirements: A study done at Middle Tennessee State University indicated that optimum fluid replacement during one hour of hard cycling is 100ml (3.5 ounces) every five minutes. The American College of Sports Medicine published a position paper in 1996 stating the athlete performs best if he replaces fluid at the same rate it is being lost through sweat.

Recommendations:

  1. Drink 2 glasses of water as soon as you wake up. You've spent a long period of time without water and the AM is optimal time to rehydrate.
  2. Drink O2 before practice
  3. Drink during practice
  4. If you are thirsty, you waited too long
  5. Keep a bottle by your lane at all times 
  6. Fluid temperature between 59-72 ̊F optimizes palatability and absorption.
  7. The fluid should be composed of a 4-8% carbohydrate concentration.
  8. Carbohydrates should be ingested at a rate of 30-60g per hour, which corresponds to the above recommendations for overall intake and composition. 
  9. Calcium, magnesium and potassium may also be present and are beneficial electrolytes. If these are not provided in the drink they should be supplemented (see below).

What to Drink/Not Drink: Avoid commercial sports drinks. This includes Gatorade, Powerade, Minute Made, etc. If you can buy it at a gas station, it probably isn’t worth it. These drinks feature glucose and sucrose as their carbohydrate components. These inhibit gastric emptying and are not well tolerated by the stomach under field conditions, although they are usually more satisfying to the taste buds. 

We prefer powder drinks such as Endurox or Cytomax. You can mix this with water and it has much less sugar than commercial drinks. 

To find out more about Hydration as well as what to eat, please check out the United States Olympic Commitee report on Nutrition for Performance here.