Tag Archives: dehydration

Preventing Heat Illness In Athletics

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“An ounce of prevention is worth a pound of cure.”

~ Benjamin Franklin

The prevention of heat illness in athletics is in the best interest of everyone involved. It takes a culture of education, understanding and proactive decision-making by coaches, athletes, parents, schools and athletic trainers in order for this to happen.

With the beginning of fall sports in early August, the combination of high temperatures and humidity is certain to create problems for athletes and athletic trainers must keep a watchful eye on them. The National Center for Catastrophic Sports Injury Research in their 2011 report, indicates there were a total of 5 deaths due to heat stroke (all at the high school level). Since 1960, there have been 132 deaths attributed to heat stroke. For a brief look at heat illnesses we previously posted, read this. The NCCSI also maintains that deaths from heat illness are unnecessary as they are preventable.
 

Here’s a look at proactive measures to prevent heat illnesses at your school or organization:

  1. An athlete must have a completed physical examination by a physician prior to beginning any type of participation in sports. This is recommended by many appropriate organizations (NCCSI, NATA, ACSM, NFHCA) and required by the MHSAA.
     
  2. Ensure that all sports and coaches follow weather related recommendations for participating in the heat and humidity, including the mandated acclimatization periods before full equipment is worn.
     
  3. Monitor weather conditions frequently (temperature, humidity, WBGT) and activate processes for curtailing sessions when required. This includes ending or cancelling sessions due to WBGT readings.
     
  4. Be an advocate for changing existing rules to encourage rest and recovery, especially those regarding two-a-days, lengthy sessions (greater than 3 hours at a time) and limit consecutive dates of sessions to 6 or less.
     
  5. Have all athletes weigh-in before and after each practice session. Loss of more than 4% to 5% of the recorded pre-practice bodyweight must be replenished prior to participation in the next practice session.
     
  6. Ensure that plenty of cold water is readily available for practices & competition. Research has shown that competitors are likely to take in more water when its temperature is cooler (55 – 57 degrees). Encourage the use of sports drinks after practice and during the overnight period to replenish fluids.
     
  7. Athletes must have freedom to access fluids during sessions – this may mean water bottles placed at each drill, or the ability to get a drink at any time.  Freedom to access means the coaches must also encourage, not discourage athletes to drink fluids and enhance the culture by not punishing, belittling or chastising athletes for asking for fluids. Build into the schedule a 10 – 15 minute water break every 25-30 minutes during hot weather.
     
  8. The ability and knowledge of the athletic trainer should be such that  immediate decisions and actions are taken to remove an athlete’s gear, move them into an air conditioned environment or possibly more aggressive measures to prevent the progression of heat illness.

Hydration Choices During Warm Weather

Posted on by oakwoodsportsmedicine

Equipment in good working order – check.

Food source appropriate for the day’s adventure – check.

Sunscreen – check.

Fluid replenishment – check and double check.

It’s summer time with temperatures and humidity reaching near-record levels. As an outdoor enthusiast or athlete, fluid replenishment should be right at the top of your list.

Sweating is a natural byproduct of exertion and provides a mechanism for dissipating our body heat. Sweat rolls over the skin and provides for cooling of the skin and superficial tissues. The more we sweat, the more fluids we lose and become dehydrated. We also lose valuable electrolytes such as sodium and potassium when we sweat.

Dehydration of a mere 2% of your body weight causes a decrease in performance – for high performance athletes this is can be the difference between a place on the podium and watching from the stands or training room. Dehydration in those of us with average abilities, still decreases our performance and places us at greater risk for heat related problems and conditions.

Engaging in intensive athletic events, practice or training in high heat and humidity is a potential situation for a number of heat related conditions.

Heat exhaustion – is a result of exposure to high temps coupled with a high level of exertion over several hours or days, resulting in a state of dehydration and often accompanied by dark, pungent urine, muscle cramps, headache, dizziness, fatigue, nausea, profuse sweating and elevated heart rate (see performance decrease with dehydration above). Remove yourself from the environment preferably in air-conditioning, take a cool shower or sponge bath, replenish fluids, rest.

Heat stroke – is a medical emergency! Heat stroke often is a progression from the milder heat related conditions (exhaustion, cramps) that are left untreated or unrecognized. Prolonged, intense exercise in hot environments >>>dehydration>>>the body’s cooling system fails. Throbbing headache, red-hot-dry skin, lack of sweating, core body temperature over 104 degrees, confusion, disorientation, elevated heart rate all or in part may be present.

Call 911 and until the ambulance arrives, get out of the hot environment, rapidly cool the person by applying ice packs to the armpits, groin, neck; immerse in cool water tub or shower.

Hyponatremia – is a condition that can be caused by, among other things, excessive loss of electrolytes over a relatively short time period. A physical examination, blood test and urinalysis will assist a physician in making the clinical diagnosis of hyponatremia.

An Ounce of Prevention Is Worth a Pound of Cure

Sports drinks are beneficial. However, the marketing cog of companies wants you to believe (and purchase) their products are necessary all day, every day. That’s not quite the case – there’s a time and place for everything.

For example, if an apparently healthy adult walks the dog in the evening for 3 miles, in hot, humid weather, then water is probably the drink of choice to consume before, during and after the walk.

For the landscaper performing strenuous physical activity for hours at a time in the hot, humid weather, a sports drink in addition to water is more appropriate.

A triathlete completing a training run during lunchtime and then a bike ride in the evening, should consider water and a sports drink following the run, before, during and possibly after the bike ride. Also a small meal or two to refill the energy stores between training sessions.

Youth athletes should be encouraged to drink plenty of water during their practice session and sports drink following the activity.

Heat illness can be prevented with education, proper planning, having resources on hand and a watchful eye.

Sports Medicine On The Road: Canton Cup Is Underway!

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The weekend forecast is calling for high temps and humidity. Be sure to hydrate the night before your game, bring plenty of cool water for in-game hydration. Once your game is over a sports drink can help replenish lost fluids and more importantly the electrolytes lost through sweating. Fresh fruit like bananas, oranges, kiwi and grapes have high levels of vitamins and water content – great for in-between game snacks.

Play on!

MYAA Football Coaches Clinic

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Join Oakwood Sports Medicine at the 4th Annual Football Coaches Clinic which begins this evening. We have a great set of topics for those attending, including injury prevention, concussion updates, how to properly hydrate youth athletes and much more!

Hydration and Nutritional Considerations in Cold Weather

Posted on by oakwoodsportsmedicine

By The Numbers

Water is an essential component for all processes the body completes each day. While most of these processes occur without our awareness, without adequate water availability they would not occur, and in cold weather, not enough water increases certain problems.

The human body is made up of 70% water; most of the water is found in and around tissues like skin and within the tiny individual cells that make up our body parts like organs. We lose water on a daily basis in the following ways:

  • 1/2L lost through normal breathing
  • 1/2L lost through perspiration
  • 1.5L lost through urine and bowel excretion
  • >2L lost through exercise

The loss of water throughout the day is usually replenished when we get thirsty. During warmer weather we are very aware of water loss because of the sweating mechanism our body uses to keep cool. But what about during colder weather; do we still lose water? Do we sweat as much during colder weather exercise?

How Does It Work?

The kidneys regulate the amount of fluid loss through urine output and actual water lost through exhalation is negligible. Food items containing caffeine (tea, chocolate and soft drinks) can increase output since caffeine acts as a diuretic. When our bodies have enough water on board to facilitate all the transactions each day, any excess can be expended through urine output.

What if there isn’t enough water on board throughout the day?

Dehydration

Dehydration can occur when we don’t take in enough water to compensate for the water lost during routine processes or exercise. How does one know if they are dehydrated?

The thirst mechanism is usually a slow reaction to an event that has already taken place and therefore not a reliable indicator of hydration.

Urinary markers for dehydration include a reduced urine volume, a high urine specific gravity, a high urine osmolality, and a dark urine color. Specific gravity and osmolality are measurements taken in a clinical setting by a healthcare professional. However, the individual easily assesses volume and color.

Other symptoms of dehydration can include:

  • Irritability, headache, fatigue
  • Weakness, dizziness, nausea
  • Having a dry or sticky mouth

Dehydration and Performance

Dehydration negatively affects competition, training and recovery during. Exercise heart rate increases, blood flow to the skin decreases which helps cool the body during exercise and the core body temperature can increase more than it should during exercise. Performance decreases with a loss of 1-2% of bodyweight. Figure 1 illustrates the relationship between performance and body water lost.

Cold Weather Hydration

Awareness, recognition and education are the ways to help prevent dehydration during cold weather training.
While proper clothing is essential during cold weather, some of the same technology that keeps us comfortable may inhibit the ability to appreciate sweat rate or water loss during exercise.

The goal is to replace 100% of sweat and electrolytes lost during exercise outdoors. The recommendations are 1/2L of fluid per kg of weight loss. Use a simple weigh-in/weigh-out procedure to determine the amount of kg’s lost. The American College of Sports Medicine (ACSM) recommends ingesting 125 ml (5 ounces) every 20 minutes of exercise.

Understand that we continue to lose fluids, even during cold weather exercise, and the importance of replacing those fluids in order to stay healthy and have a positive effect on performance.

Nutritional Considerations in Cold Weather

By The Numbers

Energy expenditure is 2X greater on wet or snow covered surfaces than on regular surfaces and the heavier clothing essential to cold weather training increases energy expenditure. Vasoconstriction, which is a reaction to cold temperatures, reduces blood flow to peripheries and thereby decreasing fat utilization. Glycogen usage increases in colder weather, resulting in fatigue.

How Does It Work?

Exercise rate at the beginning of a session can maintain body temperature, however a prolonged training session will deplete stored reserves of fuel in the form of glycogen. The resulting effect is fatigue and subsequently blood glucose and cold intolerance.

As the intensity of training decreases, muscular activity decreases, accompanied by a lower body temperature. In extreme cases, the end result is hypothermia or even death.

Cold Weather Nutrition

Maintaining cold weather nutrition presents unique challenges that must be overcome in order to stay healthy and continue training. In extreme climates, food and drinks can freeze, making them difficult to handle and ingest during a training session, not to mention palatability.

The nutrition should be high in carbohydrate content, easy to carry and access during a training session. Taking in a small meal prior to cold weather exercise is recommended; 1-4 gram of carbohydrate per kilogram of bodyweight usually 2-3 hours prior to session. This will help replenish stored fuel reserves (glycogen) in the liver. During the actual training session, 30-60 grams of carbohydrates per hour is recommended in order to replenish blood glucose.

Sample Menu

Breakfast (30 to 45 grams of Total Carb)

  • 1 cup Bran Flakes, Cheerios, Shredded Wheat or ½ cup Quaker Toasted Oatmeal Squares (23-30 grams of CARB)
  • ½ cup 1% or skim milk (6 grams of CARB)
  • ½ banana (15 grams of CARB)

Lunch (30-45 grams of Total Carb)

  • 2 slices of 100% whole wheat bread (30 grams of CARB)
  • 2 slices of Turkey Breast (not smoked), 1 slice of “Alpine Lace” or “Healthy Choice” Cheese
  • 1 small pear or apple (15 grams of CARB)
  • 1 Tbsp. of “Light” Mayonnaise
  • 1-½ cups of tossed salad & raw veggies (bell peppers, tomatoes, carrots, spinach, broccoli)
  • 1 Tablespoon of “Lite” Dressing

Dinner (30-45 grams of total carb)

  • 2 Chicken Thighs or Drumsticks or 3 oz. Chicken breast (baked & skinless with lemon and pepper)
  • 1-cup homemade macaroni and cheese (boil ½ dry macaroni and add 1 oz “lite” cheddar cheese) (35 grams of CARB)
  • 1 cup of steamed collard greens or spinach
  • 1 slice of “Low Calorie” bread (7 grams of CARB)

Snack (15 grams of total carb)

  • 1 small apple, orange pear or ½ banana or
  • 12 unsalted pretzel nuggets