At the heart of running

Common cardiovascular wisdom sees aerobic activities such as running as healthy habits that can do only good for the heart. But a study released this past summer by a German clinic has created controversy around marathon runners and the phenomenon of artery-clogging plaque that can cause heart attacks. The study, conducted at the West-German Heart Center Essen, focused on male marathoners 50 and older. Among its findings was that while the runners had lower than average cholesterol levels and better blood pressure, they had more measurable coronary calcium buildup or plaque than did the general population.

The running world has no shortage of high-profile heart attack cases. Health-book author Jim Fixx, Powerbar founder Brian Leigh Maxwell and Silent Sports magazine editor Greg Marr all were struck down by heart attacks, despite ostensibly being in perfect health.

The question raised by the German study's findings -- and being addressed by a study at the Minneapolis Heart Institute -- bucks conventional thought: Can athletic activities such as long-term marathon training actually contribute to poor heart health?

"Running is a proven healthy activity, but we're looking to find if there can be too much of a good thing," said Dr. Robert Schwartz, the Minneapolis Heart Institute cardiologist heading the study, which will look at about 50 men who have run marathons for more than 25 years straight.

Eagan resident John Tantzen, a manager at a technology company, runs up to 60 miles a week. A family history of heart disease pushed Tantzen, 48, into athletics years ago. Since the 1980s, he has competed in dozens of races, including all 27 Twin Cities Marathons.

He is thin and fit, and he has trouble keeping weight on no matter what he eats. But a recent scan revealed that he has high levels of coronary plaque.

"It was a surprise to say the least," Tantzen said.

Tantzen said he has never had high blood pressure. His cholesterol checks always came back normal. But before the scan, he was unaware of the potential for coronary plaque buildup.

"People think they are protected from heart troubles if they are in good shape," Schwartz said. "But diet and other factors can still affect coronary health in the fittest of athletes."

Beyond examining whether elite athletes are immune to cardiovascular maladies, Schwartz's study aims to assess potential links between extreme athleticism and coronary plaque buildup, which is a top cause of heart attacks.

Schwartz said stress from years of running -- including states of dehydration, exercise-induced high blood pressure, prolonged high pulse rates in events such as marathons, and the movement and twisting of arteries while on the run -- has unknown long-term effects.

Suggesting running as a potential health hazard sparked controversy with the German study, including editorials in publications such as Runner's World that questioned the test's conclusions. Schwartz hopes to provide an objective second look using a more powerful heart scanner.

With money from the Ken Rome Fund, which is named for an area runner who died of a heart attack in March, and other sources, the Minneapolis Heart Institute has about $100,000 to commit to the study. The project will take 20 months.

Schwartz and his team have scanned about 25 runners already, with 25 to go in the initial batch. Results are inconclusive thus far, he said, with subjects such as Tantzen showing high plaque levels and other runners exhibiting perfect heart health.

Schwartz hopes to publish findings in a medical journal this winter before moving on to a larger study on the subject, including the analysis of women marathoners as well as runners who are less elite.