The Heat Is On

Outdoor activities, especially sporting activities can be difficult during the summer due to the heat and humidity here in Miami.

How can a person prepare and go into battle well armed for the hot humid days ahead? There is one smart way to minimize the harsh effects of the heat: Hydration.

Miami has one of hottest and humid climates which means fluid loss. We need to continually hydrate during the week in preparation for upcoming workouts or competitions. As a rule of thumb you should drink one half your bodyweight in ounces daily. That means 75 ounces for a 150 lb. person. If you are a coffee, tea or soda drinker add another 8 oz for each caffeinated beverage consumed. Another study shows that athletes should drink 2 cups of fluid two hours before exercise and 4-6 oz every 15 minutes during exercise.

Recently there has been some attention given to the issue of hyponatremia, which is a condition where the body gets too much water and dilutes the blood salt levels which can lead to serious health issues and even death in the most severe cases. This is the reason it is important to hydrate with more that just water, especially during longer scheduled events outdoors.

Finding a sport’s drink that supplies the needed electrolytes without the high sugar content is important. One of the best fluid replacement drinks I have found on the market currently is Ultima- Replenisher. Ultima supplies the electrolytes needed to support your muscles during exercise. It is flavored with stevia and has no added sugar.

Dehydration is a serious issue. It only takes a loss of 2% of your body weight to experience a 10 -15% decrease in physical and mental performance. The key is to not wait until you are thirsty. You are already dehydrated when you feel thirsty. Susan M. Kleiner PhD, R.D and author of High Performance Nutrition states: “The thirst sensation doesn’t kick in until you have lost 2% of you body weight in fluids. This is therefore an unreliable source to rely on. Our natural indicators of thirst start to diminish about the age of 55, and are also poorly developed in children.”

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So, anyone who is waiting to drink when they are thirsty –Beware! Your body does not become more efficient as you continue this practice. It only hurts your performance in training and hurts your recovery for your future work outs. Wondering why you get those nagging cramps, headaches or stomach upsets? Blaming it on your new shoes or something you ate? Think again.

To play it safe get to know your hydration loss by completing the fluid Balance test below:

Fluid Balance test:

1) Empty your bladder and record your weight (nude)

Pre-exercise weight = ________ lbs. (A)

2) Do your run / work-out

3) Record volume of fluid drank during exercise = (D) Ounces

4) Dry off, empty your bladder and record your weight (nude)

Post-exercise weight = ___________ lbs. (B)

5) Amount of fluid weight loss in lbs. (C) = (A) - (B)

6) Convert to fluid ounces: #of lbs. X 16 = (C) fluid ounces

7) Add number of oz. consumed (D) + (C) = total fluid loss

8) Convert to lbs by dividing by 16 = (T) in lbs.

9) Percentage of body weight you lost during exercise =

(T) Total loss in lbs. X 100 / (A) original weight =

% Body Wt. lost during exercise.

Effects of loss of body weight related to symptoms and performance in the heat

2% = Decrease in heat regulation, increased thirst, up to 15%

Decrease in performance.

3% = more of the above

4% = Exercise performance decline from 20 – 30 %

5 % = headache, irritability,”spaced –out “feeling, or fatigue.

Depending on the temperature and humidity of the day, the results will change. Doing this test will give you an objective measurement and re-enforce the significance of the amount of fluid that can be lost when working out in hot environments.

Remember, listen to your body at all times – But in this case –Drink in preparation to not find yourself in desperation.

Happy Training!

Cathy Parbst P.T.

Cathy Parbst is a physical therapist in Miami. She raced as a professional Duathlete in 1998 and placed 12th in the World Championships. She was the South East Regional Duathlon Champion in 2005 &2006. You can write to her at cparbst@earthlink.net and find her at www.accursochiro.com/pt