Marathons, Ultramarathons and Heart Damage: What’s the score?

Our loved ones are often concerned about us running a full marathon or an ultramarathon.  This is especially true if you are above 50 years old.  They often question if our heart can handle the pressure.

A series of reports were presented at the European Society of Cardiology (ESC) last month.  Here are some of the findings on marathons and ultramarathons:

• Older runners — those over age 50 — developed some cardiac changes following running in Berlin marathons, but the changes in diastolic and right heart function did not exceed normal ranges.
• On the other hand, ultra-endurance running — races of 50 to 100 miles — resulted in elevation of troponin-1 which could be related to heart muscle damage; many of these runners also developed electrocardiographic changes.

One report was a study led by Fabian Knebel, MD, a cardiologist at the Medical Clinic for Cardiology, Angiology, Pneumology at the University Medicine Berlin.  It was based on 167 runners who ran the 2006 and 2007 Berlin Marathon.  All of the runners were amateurs and above 50 years old (the oldest in the study was 72).  They were examined 10 days before the race, immediately after running 26.2 miles, and two weeks after the race.

While the heart rate and troponin values have elevated right after the race, these value would be back to normal after two weeks.  What the abstract failed to mention was the speed of the runners during the marathon and what was their recovery routine.  I would suspect the subjects had a manageable pace and a full rest for two weeks.

Knebel added, “The concerns people have about marathon running causing sustained damage to the heart appear to be unfounded.  Our study looked at amateur runners with an average age of 50 – not elite athletes – and it showed that two weeks after a marathon, the key parameters were all back to normal levels.”

But doctors still suggests that newbie runners, especially those above 40, should undergo basic heart tests before training for marathons or ultramarathons.

In a separate study, John Somauroo, MD, professor of medicine at Countess of Chester Hospital, England, suggest that “running continuously over 50 to 100 miles may not be good for the heart.”

Somauroo recruited 25 Caucasian male competitors (aged 24-62) at the Lakeland 50 and 100 mile trail race in the UK.   All were normotensive, free of known cardiovascular disease and had been training for a minimum of 2 years for ultra-endurance sports events.

The cardiac Troponin I (cTnI) before the race was mostly <0.02 in 23 subjects.  After the race, 21 subjects (84%) has cTnI between 0.02 to 0.07.  Only one has cTnI still <0.02.  Others had cTnI levels of 0.11, 0.15, and 0.51 after the race.  Troponin  test is used to help diagnose a heart attack, to detect and evaluate mild to severe heart injury, and to distinguish chest pain that may be due to other causes.  It was not mentioned if another test was done weeks after the ultramarathon.

Note that these studies were published as abstracts and/or presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.