Doc’s Talk 04-29-2012

Dr. Scaff talked about post-race collapse phenomenon.

Post-race collapse phenomenon is different than collapse point.

A good example of post-race collapse is a runner who crosses the finish line, looks well, walks around, and 10 minutes later ends up in the first-aid facility hypotensive, pale, heat exhausted, perhaps even convulsing.

Post-race collapse is a physiologic phenomenon that was not understood until large numbers of people began running.  The Honolulu Marathon Clinic was the first to report it in the early part of 1973 after an older man who came to the Honolulu Marathon Clinic regularly, ran, was doing well, showed no symptoms, and while driving home ran into a wall and ended up in the hospital.  People thought he had a heart attack.  He actually experienced post-race collapse.

The Physiology of Post-Race Collapse
For every 3 miles you run, you lose approximately 1 pound of fluids.  A gallon of blood weighs about 8 pounds, and your body holds barely 1½ to 2 gallons of blood.  Therefore, if you’ve lost 6 or 7 pounds you have lost nearly your entire bloodline.

Even with the best hydration, if you weigh yourself after completing a run, you will find that you are 2 to 5 pounds lighter.  Yet, if you take your blood pressure after a run, it measures normal; though you have lost weight, your blood volume is normal; your red blood cell count may be up a little bit, but it too is still relatively normal.  So what is going on?

Teleologically, the heart is the most important organ in the body.  When it’s gone, you’re gone.  You can say a person died of an infection or AIDS or cancer, but how do we know they are dead?  When their heart stops.  The heart determines it.  So everything is geared towards preserving the heart.

As you are running the heart says, “I need fluids to keep blood flowing to let you exercise, to let you exchange heat.”  With that, fluids are taken from the tissues.  (This is why after a run you are wrinkled.  If you want to know what you are going to look like in 10 years, look at your face after a marathon.)

In this, your blood volume remains almost normal, …but you have tissue dehydration because of all the fluids coming out of your muscles.  The minute you stop running, fluids start immediately going back into the deprived tissues and blood volume decreases, meanwhile the over-exercised muscle is still producing heat, …and a devastating metabolic cascade of deterioration manifests.  With diminished blood volume, blood pressure drops, heat can no longer be exchanged, lactic acidosis begins, under-profused muscles fail further, core temperature rises, and soon the individual is in dire straits, if not unconscious.

This phenomenon can be worsened if the injured runner immediately eats food (thereby directing blood to the stomach) or ingests alcohol (which dilates the blood vessels increasing their relative capacity).

Untreated this condition is fatal!

Therefore, when you finish a run, you have to start re-hydrating again immediately, as fast as you can.  A lot of people do not feel like drinking fluids at the end of a long run, so the Honolulu Marathon Clinic recommends that you get a soda or similar beverage and just start sipping.

Treatment of Post-Race Collapse
If a person starts to show signs and symptoms of post-race collapse don’t panic.  Lay them down, bend their knees up a little bit, check to make sure they have a good pulse, and then try to give them some kind of diluted soda with caffeine and sugar.  Caffeine is a vasoconstrictor, sugar gets you out of lactic acidosis and back into carbohydrate metabolism. It is useful to have a flexible straw for them to use for sipping the beverage while they are lying down.

These people may come in after a run looking just awful, but a half hour later they are ready to go home.  This is not to say you should not call 9-1-1.  If you are really concerned you can.  The thing to remember is that when the paramedics show up, by law they are supposed to take the patient to the hospital unless the patients signs out A.M.A. (Against Medical Advice).  So if the person suffering post-race collapse gets into the ambulance, they are going to have a hospital bill which may or may not be necessary.  If by the time the ambulance arrives they are walking around and say they do not need the ambulance, send them home, no harm is done.

Be prepared
You will not see post-race collapse on your run, you will see it after the run.

You see it in the marathons:  A runner is looking great, they cross the finish line, …and puke up a quart of whatever they have been drinking.  What happened?  Their body has been shunting all of their blood to their muscles and the stomach quit absorbing fluids.

Things to remember:
1)  Post-race collapse is ubiquitous and can occur to all of us.

2)  Drinking water at the end of a marathon is not as effective as drinking in the first 10 miles when you are not thirstyThis is important.  You could really get into trouble out there if you do not pay attention.

 

Announcement
Everyone is invited to drop by the 7th Annual Hawai‘i Book & Music Festival where featured author, Dr. Jack Scaff, will be giving what promises to be a good talk on Sunday, May 06, 2012 at 2 p.m. at the Civic Grounds at Honolulu Hale
in Downtown Honolulu. For more information see:
http://www.hawaiibookandmusicfestival.org/

If you are interested in acquiring a copy of the book, 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: http://yourfirstmarathon.net/buy-online-today/

 

Nutrition
For some good reading on nutrition, Dr. Scaff recommends everyone check out the daily postings on Dr. Alan Titchenal’s “Got Nutrients?” web site: http://gotnutrients.net/tips.cfm

Here is a recent posting:

April 17, 2012
Meeting essential nutrient needs is required for optimal health. Evidence is growing that low intake of some key B vitamins may increase the risk of cancer.

Consumer Link
Just Cannot Say Enough about Importance of B Vitamins

Research Link
Br J Nutr. 2011 Sep;106(6):936-43. Epub 2011 May 16.