Fat Man Trying

December 7, 2006
Is Marathoning Too Much of a Good Thing for Your Heart?
By GRETCHEN REYNOLDS

Correction Appended

HE had not expected to spend his 60th birthday in a hospital cardiac unit. R. J. Turner, a commercial real estate broker from Frederick County, Va., had planned a robust celebration. “I was going to finish my 10th marathon,” Mr. Turner said, “which isn’t bad for a guy my age.”

But near the start of the Marine Corps Marathon on Oct. 29, Mr. Turner raised an arm to wave at bystanders, and “everything went black.” Collapsing violently, he gashed his head, chipped a tooth and bit a deep hole in his bottom lip.

Mr. Turner, who had passed a stress test a year before, had just had a heart attack.

This has been an unusual season for the cardiac health of marathoners. After years in which almost no deaths were attributed to heart attacks at this country’s major marathons, at least six runners have died in 2006.

Two police officers, one 53, the other 60, died of heart attacks at the Los Angeles Marathon in March. The hearts of three runners in their early 40s gave out during marathons in Chicago in October, San Francisco in July and the Twin Cities in October. And at the same marathon where Mr. Turner was felled, another man, 56, crumpled near the 17th mile, never to recover.

This year’s toll has sobered race directors and medical directors of marathons. But, as Rick Nealis, the director of the Marine Corps Marathon, said, “Statistically, maybe, it was inevitable.”

Race fields have grown. In 2005, 382,000 people completed a marathon in the United States, an increase of more than 80,000 since 2000, according to marathonguide.com. Meanwhile, the risk of dying from a heart attack during a marathon is about 1 in 50,000 runners, said Dr. Arthur Siegel, the director of internal medicine at McLean Hospital in Belmont, Mass., and an assistant professor of medicine at Harvard.

But some physicians, including Dr. Siegel, an author of more than two dozen studies of racers at the Boston Marathon, wonder if there is more to the deaths than mathematical inevitability: Does racing 26.2 miles put a heart at risk?

A new study by Dr. Siegel and colleagues at Massachusetts General Hospital and other institutions is at least suggestive. Sixty entrants from the 2004 and 2005 Boston Marathon were tested before and after the race. Each was given an echocardiogram to find abnormalities in heart rhythm and was checked for blood markers of cardiac problems — in particular for troponin, a protein found in cardiac muscle cells. If the heart is traumatized, troponin can show up in the blood. Its presence can determine whether there has been damage from a heart attack.

The runners (41 men, 19 women) had normal cardiac function before the marathon, with no signs of troponin in their blood. Twenty minutes after finishing, 60 percent of the group had elevated troponin levels, and 40 percent had levels high enough to indicate the destruction of heart muscle cells. Most also had noticeable changes in heart rhythms. Those who had run less than 35 miles a week leading up to the race had the highest troponin levels and the most pronounced changes in heart rhythm.

The findings, published in the Nov. 28 issue of Circulation, a journal of the American Heart Association, were a surprise, and not least to the runners. None had reported chest pains or shortness of breath at the finish. All had felt fine, Dr. Siegel said (to the extent one can feel fine after pounding through 26.2 miles).

Within days, the abnormalities disappeared. But something seemed to have happened in the race. “Their hearts appeared to have been stunned,” Dr. Siegel said.

“Although the evidence is not conclusive, it does look like the Boston study is showing some effect on cardiac muscle,” said Dr. Paul D. Thompson, 59, the director of cardiology at Hartford Hospital in Connecticut, and an author of an editorial that accompanied the study. “It’s far too early to draw any conclusions,” he added. “We’d be seeing lots more bodies piling up if there were real lingering long-term cardiac damage” caused by running marathons.

“Over all, the evidence is strongly in favor of the idea that endurance exercise is helpful in terms of cardiac health,” said Dr. Thompson, who has run more than 30 marathons.

But questions do remain. Another new study, this one out of the University of Duisburg-Essen in Germany, showed completely unexpected results in a group of experienced middle-aged male marathoners. In the study, which was presented in November at a meeting of the American Heart Association, the subjects, each of whom had completed at least five marathons, underwent an advanced type of heart screening called an electron beam CT scan. Unlike echocardiograms or stress tests, electron beam CTs show the level of calcium plaque buildup or atherosclerosis in the arteries.

More than a third of the runners had significant calcium deposits, suggesting they were at relatively high risk for a heart attack. Only 22 percent of a control group of nonrunners had a comparable buildup.

The researchers scrupulously avoided suggesting that marathoning had caused the men to develop heart disease. (After all, running may have kept them alive when they would otherwise have keeled over years earlier.) But neither did the authors rule out the possibility that in some baffling way distance running had contributed to the men’s arterial gunk.

What worries Dr. Siegel and some of his colleagues is that marathons present an opportunity for silent symptomless heart disease to introduce itself abruptly. The pulsing excitement, the adrenaline, the unpleasant process of “hitting the wall” may trigger physiological changes that loosen arterial plaques, precipitating a heart attack, Dr. Siegel said.

His advice to runners with any history of heart trouble is “train for the race, getting the cardiac benefits of endurance exercise,” then watch the event on television.

The risk of going into cardiac arrest as a spectator, he said, is only about one in a million. (The applicable studies of spectators involved Super Bowl fans.)

Anyone considering joining the ranks of marathoners should undergo a full medical screening, with a visit to a cardiologist for those over 40, Dr. Siegel said. Spiral or electron beam CT scans are desirable (the cost can range from $250 to $850) and are covered by insurance if recommended by a physician.

Those with a family history of cardiac problems should be especially cautious. “You can’t outrun your genes,” Dr. Siegel said, a reality that marathon medical experts call the Jim Fixx effect, after the author of “The Complete Book of Running,” who died of a heart attack in 1984 at 52. His father had also died young.

Still, the majority of cardiologists remain avid fans of marathons. “It is an extraordinary event,” said Dr. Frederick C. Lough, the director of cardiac surgery at George Washington University Hospital in Washington. “But you have to respect that distance. It’s not something everyone necessarily should attempt.”

Dr. Lough, 57, was less than a block behind Mr. Turner when the older man collapsed. He interrupted his own race to help revive Mr. Turner and accompany him to the hospital, before completing the marathon. “It was a vivid reminder that running does not make anyone immune to heart disease,” Dr. Lough said.

Experts familiar with the new cardiac studies of marathoners urge caution and perspective. The numbers of people studied were small, the findings unexplained, and results have not yet been replicated.

Don’t use the studies, in other words, to justify parking yourself smugly on the couch. “There’s not yet in my opinion cause for alarm,” Dr. Thompson said. “I would still tell people, run.”

His words doubtless will cheer Mr. Turner. “You know the worst thing about almost dying?” he said. “That I didn’t finish.” After having had a stent installed in his heart to open an artery that was about 98 percent blocked, he’s now walking a mile a day and planning his comeback. “I want to get that 10th marathon in,” he said.

But not before he gets a full medical screening, including an electron beam CT scan.

Correction: December 21, 2006

An article on Dec. 7 about marathon running’s effects on the heart misstated the type of diagnostic machine used in a study by the University of Duisburg-Essen in Germany. It is an electron-beam CT scan, which uses electron beams to show the interior of coronary arteries, not a spiral CT scan, which uses X-rays to do so.

Will exercise help prevent you from developing heart disease in the first place?

The answer is yes to both questions. Previously people with established heart disease were told to “take it easy” and not stress their heart too much. The opposite is now true with cardiac rehabilitation programmes emphasising exercise as part of the lifestyle changes needed to improve cardiac functioning and prevent further damage. It is also an integral part of the treatment of people who have suffered heart attacks.

Over the past decade or so there has been plenty of research showing that exercise can be an effective part of the treatment plan for someone with coronary artery disease.

There are two main reasons why people with heart disease should exercise:

to slow the course of the disease
to rehabilitate themselves by using exercise to restore normal or near normal function of the heart and the lungs

Exercise is important for people who do not have heart disease as well. Lack of exercise has been shown to be one of the main risk factors for developing heart disease.

How much exercise is needed?

The use of exercise to either prevent or treat heart disease is based on the idea that exercise will increase you ability to function – your functional capacity. This means that you will find it easier to walk particular distances, climb stairs without becoming short of breath and enjoy activities such as gardening without becoming too tired. This will only happen with a regular training programme.

The recommended workload is a programme which provides exercise in the range of 70 to 80% of your maximum heart rate. This usually equates to an energy expenditure of around 300 kilocalories per session. The heart needs to be slightly overloaded since this will force it to adapt to a greater capacity than it was at previously. You should exercise to a level where you feel your exertion to be at least moderately hard, but you are still able to sustain this comfortably for around 30 to 40 minutes.

This is of course the baseline and for anyone with established heart disease the programme must be worked out in conjunction with a doctor or cardiac rehabilitation centre.

But this is not to say that people with heart disease can only exercise at this level. Once the initial rehabilitation is done, there are plenty of people who have carried onto much higher intensity exercise and have become endurance runners or cyclists and continue training at a very high level.

What is safe exercise if you have a heart condition?

If you don’t have heart disease and simply want to keep fit then any regular exercise programme which you enjoy and will stick to is fine. But if you have recently had unusual shortness of breath or any chest pain, then you should see your doctor before you start.

If you have a recognised heart condition, then you must have a programme worked out for you by a professional exercise trainer in consultation with your doctor and you must use a heart rate monitor while exercising. If you are recovering from a heart attack then you must only exercise within a recognised cardiac rehabilitation centre programme.

People who have heart disease should have a graded exercise stress test before starting any type of exercise programme. This allows an assessment of your ability to tolerate gradual increases in the intensity of exercise.

How do you know if what you are doing is safe?

Once you have started exercising regularly you need to know the symptoms which should stop you from exercising immediately:

Pain or discomfort in your chest, stomach, back, neck, jaw or arms – never exercise to a point where you have pain in any of these areas. They can indicated lack of oxygen to your heart (ischaemia). If you feel pain in any of these areas, slow down or stop completely and tell your trainer.
Unaccustomed shortness of breath during exercise – if you suddenly find that you cannot do the same amount of exercise which was previously comfortable without becoming uncomfortably short of breath, then you need to see your doctor. If the change has appeared gradually over a period of weeks, then make an appointment to see your doctor within a week. If this is something you experience suddenly, then see a doctor immediately.
If you feel dizzy or faint either immediately after or during exercise, then stop and lie flat on your back with your legs up on a chair. Arrange to see your doctor as soon as possible for a check up. It may simply be that you are overdoing it a bit and need to slow down.
If you feel nauseous during exercise follow the same procedure as for dizziness.
An irregular pulse when your pulse is usually regular during exercise needs to be investigated. Tell your trainer and arrange to see your doctor.

Beta-blockers and calcium channel blockers alter your heart rate. Make sure that your trainer knows which drugs you are on and continue to take them as usual when you start exercising.

What type of exercise should you be doing?

Aerobic exercise specifically trains the cardiovascular system. Activities such as walking, jogging, cycling, swimming, rowing, stair climbing, dance and skipping are particularly good since they are continuous exercise and give you endurance capacity as well.

The type and intensity of exercise will vary depending on your level of fitness, motivation and capacity. You can work this out with your trainer.

Exercise should be something you enjoy so that you will stick to it. Don’t take up jogging if you hate it! You won’t keep it up and may become demotivated for any type of exercise at all.

You should maintain and improve flexibility since this makes exercise more enjoyable and you are less likely to get injured. So warm up and stretching are important parts of any exercise programme.

Resistance training with weights was previously thought to be potentially dangerous in people with heart disease. Now we know that improving muscle strength and tone relieves strain on the heart, so this is an important part of exercise as well. However, don’t push big weights which will make you strain. Rather stick to light weights and increase your number of repetitions as you get fitter. Speak to your trainer about this.

A well worked-out exercise programme will have three elements:

aerobic exercise
stretching programmes
strength training

Always start at a comfortable level and increase the intensity gradually - usually over a period of six months. You should exercise for a minimum of 30 minutes three or four times a week.

Exercise should become part of your regular routine – enjoy it and get the best out of it!

Breakthrough findings by Swiss cardiologists have suggested that physical exercise might well improve coronary circulation in coronary artery disease and is certainly well worth investigating as a treatment.

The cardiologists have shown for the first time that a physical endurance exercise programme in a human volunteer increased coronary flow through arteriogenesis— transformation of existing collateral arteriolar pathways into conducting vessels.

A 46 year old male healthy cardiologist with a 25 year history of amateur marathon running, who was put through a long term controlled programme of aerobic endurance training, showed a collateral flow index raised by over 60% at high fitness relative to intermediate fitness. The increased coronary flow could be attributed only to arteriogenesis because he had normal coronary arteries and had never before the tests experienced anginal pain, therefore ruling out exercise induced ischaemia, which stimulates vessel growth by angiogenesis—formation of a new capillary network.

Coronary circulation was assessed non-invasively and invasively at baseline; intermediate fitness; and high fitness, just after completing an alpine ultramarathon of 78.5 km and height profile of 2000 m. Low fitness (baseline) comprised two hours’ training a week continuously; intermediate fitness four hours a week for four months; and high fitness 8–9 hours a week for four months.

In heart disease when the coronary arteries become blocked remodelling in arteriogenesis comes about by high shear forces at the vessel wall. This means that exercise should open up collateral coronary circulation, but that remained to be proved—until now.

Endurance exercises such as running and cycling may protect older people from cardiac injury during a heart attack, according to a new University of Florida study.

Through experiments with rats, the researchers discovered that exercising one hour a day for three consecutive days offers the heart just as much protection in the animal as if it ran five days a week for 10 weeks, said professor Scott Powers, director of the Center for Exercise Science and a contributing author to the study.

The finding contradicts the conventional belief that it takes weeks or even months of exercise training to reap the benefits of exercise; it turns out protection against a heart attack can be obtained in just three days and lasts more than a week.

“You stay protected up to about nine days,” said Powers. “By day 18, you’re completely back to where you started. So the only way to maintain it is to be active.”

In the study, which appears in this month’s issue of the journal Experimental Gerontology, young and old rats ran on a treadmill at approximately 60 to 70 percent of their exercise capacity. Exercise increased their levels of the antioxidant superoxide dismutase, which provides cardiovascular protection. Additional experiments have shown that exercise-induced increases in this antioxidant are critical for the heart to develop the full protective benefits of exercise.

Powers said that in approximately 90 percent of heart attacks, blockage created in the vessels triggers a clot that can damage the heart. “If you don’t break down the clot, the heart cells are going to die,” he said.

Powers added that even if the clot dissolves naturally, damage still occurs when blood flow is restored to the heart because the oxygen level is increased and forms an unhealthy abundance of free radicals that damage the heart muscle. This process, called ischemia reperfusion injury, makes the heart weaker and decreases its working capacity, according to the study.

Powers said that’s “because you can think of the heart as the engine that runs the car. So if you chop off cylinder after cylinder from the engine, eventually it’s going to be underpowered.”

In humans, exercises such as cycling, swimming, running and walking may cause heart muscle cells to produce more antioxidants that protect the heart during the insult of a heart attack.

Powers and John Quindry, postdoctoral fellow and a contributing author to the study, also concluded that exercise protects against cell death caused by apoptosis, or programmed cell death, which had been previously unknown.

Powers said the study may help to determine why endurance exercises provide the heart protection. Once that is known, researchers could design better exercise strategies, or develop a drug approach to turn on the genes that are activated during exercise.

“That would be extremely useful for people who are wheelchair-bound, aren’t ambulatory, or just people who have orthopedic problems or won’t exercise,” said Powers.

Li Li Ji, a professor of kinesiology at the University of Wisconsin-Madison, said the UF research is important because it shows that independent of age, endurance exercise can reduce injury sustained during a heart attack.

“These experiments for the first time demonstrate that exercise can protect the heart against ischemic insult in both young and old animals,” he said.

The study was also conducted by doctoral candidates Joel French and Youngil Lee and former UF assistant scientist Karyn Hamilton.