Does extreme distance running go too far?

ronadams52

Heart attack risks are greater for athletes who compete in endurance sports


Endurance athletes who exercise for three hours or more have an increased chance of dying from a cardiac arrest

Why heart muscle cells may die during prolonged exercise

Why were cardiac troponin I concentrations up after the Austrian race? According to the researchers, many of the well-trained athletes probably experienced sub-clinical cardiac injury during the event and this was associated with the actual deaths of heart-muscle cells. The mechanism underlying such cardiac cell deaths is unknown, although one popular theory suggests that the heightened adrenaline/noradrenaline levels sometimes observed during prolonged exercise rather perversely lead to the constriction of coronary arteries, which results in localised cell death within the heart. (Adrenaline and noradrenaline - also known as epinephrine and norepinephrine - are hormones released by the adrenal glands in response to stressful situations.)

Heart-cell death during strenuous exercise? Yes, it is a bit like having a small heart attack at the same time that your heart is performing magnificently! In fact, cardiac troponin I is usually undetectable in the blood serum of healthy people but is typically found in those who have suffered a myocardial infarction (heart attack), congestive heart failure, or myocarditis (inflammation of the heart muscle). In fact, the enzyme is used predictively by heart specialists: the higher the level in a particular patient, the poorer his prognosis.

This sounds bad! But has anyone besides the Austrians uncovered evidence of heart-structure damage after strenuous exercise? Actually, yes: one study of finishers in the Hawaii Ironman Triathlon found that 9% displayed elevated cardiac troponin 1 levels and, further, that these individuals also exhibited abnormal heart wall action and function during echocardiographic analyses(3). Another investigation found cardiac-troponin increases in 11% of the finishers of an alpine cross-country marathon (4).

Is the positive post-exercise increase in cardiac troponin I really something to worry about? Were the heart cell deaths merely a small piece of the cardiac pie? Could the lost cells be replaced by regrowth of healthy heart tissue? These key questions are very difficult to answer, especially as no histological analyses of heart tissue were performed as part of these studies, and neither were echocardiograms or electrocardiograms (ECG) carried out to determine whether heart function was impaired. To play it safe, the Austrian researchers suggested that endurance athletes 'should at least undergo serial cardiovascular examinations looking for subtle evidence of myocardial dysfunction'.

References
1. Journal of the American College of Cardiology, vol 28, pp 428-431, 1996
2. American Journal of Cardiology, vol 87, pp 369-371, 2000
3. American Journal of Cardiology, vol 83, pp 1085-1089, 1999
4. Journal of the American Medical Association, vol 282, p19, 1999
5. American Journal of Cardiology, vol 80, pp 379-380, 1997
6. American Journal of Cardiology, vol 88, pp 920-923, 2001
7. New England Journal of Medicine, vol 311, pp 874-877, 1984
8. Journal of the American Medical Association, vol 247(18), pp 2535-2538, 1982
9. New England Journal of Medicine, vol 293, pp 367-371, 1975
10. The New England Journal of Medicine, vol 301, pp 792-793, 1979
11. Chest, vol 77, pp 94-97, 1980
12. Running Research News, vol 5(6), pp 1, 6-10, November-December 1989
13. The New England Journal of Medicine, vol 321, pp 320-324, 1989

BrianSharpe

Heart attack risks are greater for athletes who compete in endurance sports

Greater than what? The general population....no, by far lower than the average sedentary person.

BTW.....nice cut & paste. If you're going to copy a whole article at least have the decency to attribute it to the copyright holders (http://www.pponline.co.uk/encyc/heart-attack-risks-are-greater-for-athletes-who-compete-in-endurance-sports-263)

chivalryder

I haven't heard of many recent Tour de France racers falling down and dying from a heart attack. Yes, it used to happen back in the 70's and earlier, but never recently. The technology, training, and food they eat is so much better than before, it is a very rare occurrence.

I have to ask: Why are you posting all this? It seems rather futile. How many people on here are going to run for 3+ hours any time soon?

brandyk77

I am impressed by those who can do ultras - not looking to tell them to stop. It is still far healthier than doing nothing.

I personally think that a marathon may be my limit. My coach thinks I should do a 12 hour race just because he thinks I would excel at it. I am not sure if I am there mentally yet.

tri10806

We're all going to die from something. While I'm here I'm going to push my limits and enjoy every minute I have.

Impossible is not a word; it's just a reason for someone not to try. ~Kutless

tappae

I have to ask: Why are you posting all this? It seems rather futile. How many people on here are going to run for 3+ hours any time soon?

I'm actually planning a 3 hour run for tomorrow morning.

Since I want to run my first ultra next year and a 100-miler is part of my "5 year plan" I am interested in any research that definitely shows it to be unreasonably dangerous.

Right now, though, I can look at my family's medical history and realize that being sedentary will very likely lead to diabetes, heart disease and stroke. I think I'll keep running.

karenfaber

I'm running my first 50-miler this Saturday. In the last four years I've run 14 marathons and 4 50Ks in addition to many half marathons, 10Ks, 5Ks, relays, etc. I've also dropped 32 pounds since the beginning of the year.

I doubt I've ever been healthier than I am right now. My blood pressure is generally around 90/70 and my heart rate under 50 bpm. I have gotten completely off of the anti-depressant I was on for several years and am no longer in therapy for anxiety and depression. I'm rarely sick. So if I am in the extremely small number of people that die while running (which I'm sure is much smaller than the number of people that die sitting on the couch in front of the TV), at least I will die doing something I love. Taking up running is one of the best things I've ever done for myself.

ixap

Since I want to run my first ultra next year and a 100-miler is part of my "5 year plan" I am interested in any research that definitely shows it to be unreasonably dangerous.

I agree! I am always interested in studies on this topic.
I also agree that thus far the evidence is not sufficient for me to change my plans.