HYDRATION FOR ATHLETES

By Jesse Kropelnicki & Jaime Windrow – The Core Diet

Hydration is an important factor year-round to overall health. Slight dehydration of even 2% of your body weight can negatively affect performance, and it’s been shown in studies that this nutritional intervention of staying properly hydrating is the best way to enhance or improve performance.

DEHYDRATION

The most common situations that cause athletes run into dehydration troubles:

  • More than 1 training session per day.
  • Competitions held in hot and/or humid environments; if the athlete is coming from a colder climate, the impact is even larger.
  • Competitions of long duration such as marathons and triathlons (specifically half and full ironman distances).

 

Signs that you’re dehydrated:

  • Dizziness, confusion, lightheaded
  • Dry lips, mouth and skin
  • Physical and mental fatigue
  • Decrease pace and performance
  • Darkened urine (one of first indicators because the kidneys are very sensitive and they will let you know!)
  • Increased body temperature, HR and RPE

 

OVERHYDRATION - HYPONATREMIA

Dehydration is a common concern but overhydration, or hyponatremia, can be an overwhelming concern for endurance athletes who tend to spend consecutive hours training or racing.

Drinking water is important, but too much water with too few electrolytes impairs performance and body function. This metabolic condition in which there is not enough sodium (salt) in the body fluids can be caused by over-hydrating and/or hydrating with only water, which can flush electrolytes from your body. Nuun is perfect for pre-event or during the day hydration as they contain sodium but without much of the un-needed carbohydrates many sports drinks have.

Signs of hyponatremia include:

  • Nausea and vomiting
  • Headache
  • Confusion
  • Loss of energy
  • Fatigue
  • Restlessness and irritability
  • Muscle weakness, spasms or cramps
  • Seizures
  • Unconsciousness
  • Coma

 

HYDRATION RATE – HOW MUCH DO I NEED TO DRINK?

We frequently get asked, “How much Nuun should I drink?” but the answer depends on many factors, including but not limited to body physiology, fitness, temperature, intensity of training, and diet. We recommend that athletes perform a sweat test to determine how much water is shed during training, and electrolytes can be fine tuned from there.

Calculating Your Sweat Rate
Average sweat rate is typically 1 – 1.5L of fluid per hour (32-48oz), and 500 – 1,500mg of sodium per hour, however your personal sweat rate will depend on several factors such the environmental conditions (temperature, humidity); genetics, and the athletic conditioning of the athlete.

Your sweat rate can be determined by a simple "sweat test":

  • Take body weight before a one-hour moderate intensity bike or run.
  • Record the amount of liquid consumed during workout, and weigh yourself again after the workout.
  • Calculate the weight change and remember to add in the amount of liquid consumed during the workout.
  • Every pound lost during your workout is equal to 16 oz of fluid.
  • Most people’s sweat contains about 500mg of sodium per 16oz. Very salty sweaters can have up to 1000mg or 1500mg per 16oz of sweat. As a very general rule of thumb, during long walking or running events, you should pee a minimum of every 2.5 hours to ensure you are staying hydrated.

 

Keys to hydration success:

  • Drink fluids throughout the day and before/during/post workouts. Maintaining a good hydration status on a daily basis by staying a step ahead of dehydration is the best approach.
  • Waiting until you are thirsty to drink fluids is too late – you are already dehydrated and you’ll find yourself constantly playing the game of catch-up!
  • Each day try to consume half your body weight (in pounds) in liquid ounces PLUS what you sweat out in training (your sweat rate). For example, if you weigh 150 pounds, you should aim to consume 75 ounces of water or electrolyte drink per day plus losses that occur during workouts.

 

About The Core Diet
Jesse Kropelnicki is an elite triathlon coach and founder of TheCoreDiet.com, a leading provider of sports nutrition. He coaches professional triathletes Caitlin Snow, Ethan Brown, and Pedro Gomes with quantitative training and nutrition protocols. Jaime Windrow is a Registered Dietitian and the Nutrition Programs Director at TheCoreDiet.com. Jamie holds a number of age-group wins and podium finishes, as well as a finish in Kona at the Ironman World Championships.