Hot Weather Hydration

Whether you take your training outdoors to hit the trails or stay inside to hit the bag, don’t let the summer heat take a toll on your performance—stay hydrated.

Proper hydration should always be a priority for fighters, and it’s especially vital to pay close attention to your hydration needs in the summertime. During exercise, contracting muscles generate internal heat and raise the core body temperature. This heat is released via blood flow from themuscles to the skin. Sweating further accelerates this exchange, as sweat evaporates from the skin and you begin to cool down. However, with summer’s high heat and humidity added to the mix, this well-designed system that keeps you from overheating can be thrown for a bit of a loop. When the air around you is hot and moisture-heavy, sweat builds up and drips off your body, and the benefi cial cooling effect of sweat evaporation is lost.


Your fluid and electrolytes need to be replaced before negative effects wreak havoc on your athletic performance. With as little as a 2% loss of body weight in sweat, your speed, strength, endurance, coordination, and cognitive function can decline, while your perceived sense of exertion and exercise difficulty can rise.

Because higher heat and humidity provide additional challenges to your hydration status, don’t start out behind the eight ball. Come into training sessions and competition in a properly hydrated state. An easy way to check this throughout the day is via urine. Frequent trips to the bathroom yielding pale, straw-colored to light-yellow colored urine are indicators of being hydrated. Infrequent, dark colored urine is typically a sign of dehydration. Headaches, swollen hands and feet, drowsiness, diffi culty concentrating, dry/cracked lips, and nausea are other possible signs of dehydration.

For regular day-to-day hydration and for shorter workouts lasting less than one hour, water is typically sufficient. Approximately 60% of your body weight is water. You lose water daily via urine, respiration, and sweat, and replacement is vital for both athletic and general health reasons. Water is required for body temperature regulation, lubrication of joints, injury prevention, digestive function, and muscle contraction. For longer training sessions or those in hot environments, you’ll want a well-designed sports drink. These beverages cover fl uid, fuel (from carbs), and electrolyte needs and should always be within reach during rough summer training sessions. It’s during these sweat-soaked workouts that electrolytes take center stage.


Electrolytes are minerals that break into small, electrically charged particles (ions) when dissolved in water. Sodium, potassium, chloride, calcium, and magnesium are among the body’s most important electrolytes, aiding in fl uid regulation, pH balance, transmission of nerve impulses, and muscle contractions.

The main electrolytes lost in sweat are sodium, potassium, and chloride. Sodium is typically the frontrunner and most important to replace, as its functions include aiding in fl uid balance, stimulating thirst (and the drive to drink to stay hydrated), and helping to reduce muscle cramping. Working hard in a hot environment, athletes can lose up to two liters of sweat per hour, with each liter taking 500 to 1000mg of sodium with it. You won’t replace all fluid and electrolyte losses during your workout, but strive to replace enough during activity so you perform at optimal levels. The rest can be replaced as part of your post-exercise refueling.

Popular choices for well-designed sports drinks include certain beverages from the Gatorade G series (Gatorade 02 Perform, Gatorade G Natural) and Ironman Perform from PowerBar. These will provide 50-70 calories and 14-17 grams of carbs (the recommended 6-8 percent carbohydrate solution), 100-190mg of sodium, and 10-30mg of potassium per 8 fl uid ounces. The “Natural” line has a cleaner ingredient list (versus the original 02 Perform), boasting sea salt and the removal of artifi cial colorings and dyes. Lower-carb/stevia-sweetened electrolyte replacement products available include Gatorade G2 Natural, Gatorade G Fit 02 Perform, and Vega Sport electrolyte Hydrator (portable sleeve of powder to be mixed in water).

With workouts lasting more than one hour or when exercising in the heat, most fluid (especially during and after activity) should be in the form of a sports drink, or alternate between a sports drink and water.


On the other end of the spectrum, hyponatremia (over-hydration) occurs when blood sodium concentration drops to dangerous levels. This potentially life-threatening condition may occur in athletes using only water (versus a sports drink) to replace sweat losses, those who consume excessive amounts of water prior to exercise, ultra-endurance athletes, and those exercising in extremely hot conditions. Because many signs and symptoms of hyponatremia are similar to dehydration (nausea, swollen hands and feet, rowsiness, and headache), a professional diagnosis is needed. One major difference is that there’s typically weight gain throughout he workout, versus weight loss with dehydration. Treatment can range from consuming foods and beverages containing sodium to intravenous (IV) fluid under medical care.

Don’t let rising temperatures and that big ball of fi re in the sky keep you from performing at your best. Having plenty of water and sports beverages on hand before, during, and after training is a must for fi ghters of all levels.


• 15-30 minutes prior to exercise:
8 to 16 ounces of fluid.

• During exercise:
5 to 12 ounces of fluid every 15-20 minutes as tolerated, or approximately 16 to 33 fluid ounces (½ to 1 liter) per hour.

• Recovery / Post-exercise:
16 to 24 fluid ounces per pound of body weight lost (weighing yourself immediately before and after training a few times will allow you to calculate an average loss of body weight and an amount of recovery fluid needed).

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