Doc’s Talk 04-14-2013





The eyes of all warm-blooded carnivores point straight ahead.  The eyes of all warm-blooded herbivores point sideways.  This allows them to look sideways while they are eating to see if the straight-eyed animal is approaching them, because the rule of survival was not to get caught at the wrong end of the food chain.

Man is a straight-eyed animal.  Something else interesting about man’s eyes is that humans have color visionthe other carnivores do not because they only eat meat.  When humans are out running it is much easier to catch nuts and berries than it is another animal, but more importantly, that was a survival mechanism. Man could eat the vegetables, and during periods of famine or drought, man could eat what ate the vegetables (the cow, the horse, etc.).  Since man could go back and forth, he is a true omnivore.

Dr. Scaff talked about heat exchange.

Our body warms up to about 101°F while we are running.  Heat is a byproduct of work, it is what we call the warm-up, it is good for us, …but when you start loosing a certain percentage of your body weight, temperature starts to increase.  When you have lost about 10 percent (actually a little less than that) of your body weight, you start to go into heat strokewhich untreated could be fatal.  We don’t want that to ever happen, but, our temperature is definitely going to go up in the marathon, particularly if it is a hot and humid day.

Four ways you get rid of heat:
1)  Radiation:  Like the heat emitted by a light bulb.  If you have picked up a baby with a high fever you can feel the baby radiating.

2)  Convection:  Heat rises.  Watching a football game on a cold wet day, when the players sit down on the sidelines you can see steam (heat) rising off the top of their heads.  You radiate heat and it gets carried upwards.

3)  Conduction:  The direct transmission of heat.  When you sit on a cold bench, you are conducting heat from your body.

4)  Evaporation:  To raise 1 gram of water by 1 degree Centigrade (Celsius), requires 1 calorie (a calorie is a measure of heat exchange).  To evaporate 1 gram of water takes over 300 calories.

So evaporation is about 400 times as effective as all other methods of getting rid of heat.  Thus, when you are running and see a drop of your precious bodily fluid coming down your elbows onto the street, you have lost your most effective heat exchange mechanism.  We want the sweat, but we want it to stay with us.  What is the best way to do that?  Use a singlet (running shirt).

A good singlet has little holes in it, and it wicks the sweat and allows air to circulate.  A t-shirt is not that good.

When you are out running, if you are wearing a singlet, feel the front of your chest, and it will be cool, even though the rest of you is hot.  Those of us who are darkly complected will benefit from wearing a white singlet because the darker the shirt is the more heat we absorb.  So on the day of a race we all want to be in a white shirt.  A white t-shirt is actually better than running without a shirt at all because more of the sweat gets away from you.

Where can we not conserve heat?  The chest.  Doing astronaut studies, scientists threw the astronauts in ice water until they turned purple, and then measured where heat was escaping.  Heat was escaping the chest and the top of the head, …because man is a runner, and when he ran, the heat would come across his chest, and since he ran more than women he kept the hair on his chest so that he could wick the sweat and help it evaporate.  Dr. Scaff says there is a reason for everything, and it can all be thought of.

So basically, we want you to wear the right kind of equipment and we want to make sure you replace your fluids.  We replace our fluids, normally 10 ounces of regular water, every 20 minutes.

If you weigh a gallon of water you will see it weighs 8 pounds.  Do you have to drink all of that and then drink your daily requirements to replace your fluids?  The answer is yes.  Should you add some electrolytes to it?  Yes, if you like.  Pretzels are fine.  Your body processes salt pretty well, however, if you are an individual with hypertension, if you have read Dr. Scaff’s book, you need more salt, not less salt.  Salt restriction can cause problems.  These are things you have to work out with your doctor, however, you do not have to worry about getting rid of salt.  In Hawaii we have very salty foods, but after you come back from a run, after you have dried out a little bit, lick your elbow.  It is salty.  That is why you need electrolytes because after we are running our urine production ceases, particularly if we are breaking 4 hours in the marathon.  Our skin becomes the kidneys of the body.  Sometimes the sweat actually smells like urea, but it is not as effective as conserving electrolytes, so be a little bit more liberal in what you eat and drink.  You will get your magnesium from meat and your calcium from milk or whatever else it is, and you get your sodium from everything else.  So just don’t be afraid of electrolytes.

For more information on heat exchange and other running topics, read Your First Marathon – The Last Word In Long Distance Running, by Jack H. Scaff Jr., M.D., F.A.C.S.M., available for purchase at the Honolulu Marathon Clinic on Sundays and online at:

Next week:  Post-Race Collapse Phenomenon. The Honolulu Marathon Clinic was the first to report Post-Race Collapse Phenomenon in the U.S.  Today everybody is aware of it.




April 9, 2013
The odds of living a long and healthy life are greatly increased if risk factors like blood pressure, blood cholesterol, and blood sugar are maintained within healthy ranges along with not smoking. Doing this has been estimated to increase the lifespan by as much as 14 years.

Consumer Link
Living a Healthy Lifestyle and the Benefits of a Lifelong Plan

Research Link
JAMA. 2012 Nov 7;308(17):1795-801.