The Heat Is On

Posted by on Jan 13, 2012 in What You Should Know | 0 comments

Running is a tough enough sport without having to battle the tropical humidity and heat of Miami. How can a runner prepare and go into battle well armed for the hot humid days ahead? There are some smart ways to minimize the harsh effects of the heat: Hydration.

Miami has one of hottest and humid climates which mean fluid loss for athletes. Runners should continually hydrate during the week in preparation for their long runs. 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 I have been reading about 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 your longer runs. Find a sport’s drink that supplies the needed electrolytes without the high sugar content. One of the best fluid replacement drinks I have found on the market currently is Ultima- replenisher (No they are not a sponsor of mine, nor is this an add for them) Ultima supplies the electrolytes needed to support your muscles during exercise. It is flavored with stevia and has no added sugar.

If you are a novice runner you should plan your long runs to occur before or after the hottest part of the day. You should also take fluids with you or have them planted throughout your run course. It is fortunate we have dedicated running clubs that put out water for the runners. Thank you!

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 is also poorly developed in children.

If you are a subscriber to Runner’s World, you may have noticed the attention it gave to heat issues this month. According to Runner’s World, the IMMDA (International Marathon Medical Directors Association) has recently released their hydration guidelines that state “Thirst will actually protect athletes from the hazards of under drinking”

Apparently the members of the IMMDA have never had the pleasure of running 10 miles in Miami during the summer months!!

So, all you athletes that are passing up the water stops –Beware! Your body does not become more efficient as you continue this practice. It only hurts your performance in training and at the races. Wondering why you get those nagging cramps, headaches or upset stomachs? Blaming it on your new shoes? Think again.

I am still amazed at the number of runners that are considered veterans to the sport and good athletes that pass up those water stops. On a recent run, a fellow runner stated he was sure that not drinking at the 8 mile water stop would affect him. He was drenched in sweat and continued to run another 2.5 miles. Can you imagine if he kept his body hydrated, how much better he would recover and feel? Unfortunately he will never know.

80 % of the injuries I treat are contributed to by poor hydration and electrolyte imbalance. In a case study I had one of my patients with a nagging calf strain commit to hydrating daily at one half his body weight in ounces. After one week his calf problems seem to disappear and another thing happened – He noticed his energy levels were increased throughout the day.

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,

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 running 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 has defended

her title this year as Regional Duathlon Champion and has

qualified for the World Duathlon Championships in May 2007 in

Gyor, Hungary. You can write to her at

and find her at

Leave a Reply