“Yet another study on endurance athletes suggests that exercise, like everything else in life, has an upper limit.”

Here goes, buckle up.

The study titled, Exercise-induced right ventricular dysfunction and structural remodeling in endurance athletes was published last week in the European Heart Journal.

Researchers from Belgium and Australia enrolled 40 long-term endurance athletes in a study looking at heart function after an endurance race. All subjects were long-term exercisers and were accomplished athletes with above average fitness. They were elite.

By measuring cardiac enzymes (heart injury) and taking ultrasounds (directly seeing heart function) immediately after 4 different length races (marathon through ‘ultra-triathlon’), researchers were able to measure the acute effects of extreme exercise on the heart. MRI scans performed a week later assessed for cardiac scar tissue. (The presence of scar in heart muscle portends trouble because it disrupts electrical signals.)

The main findings:

Compared to pre-race measures, right ventricular (RV) function diminished post-race, whereas LV function remained normal.

Blood levels of cardiac enzymes increased post race and these rises correlated with the amount of RV impairment.

The degree to which RV function decreased correlated with increasing race length and an athletes’ VO2 max.

12% of athletes had scar detected on MRI scans at 1 week post-race. Those with scar reported greater cumulative exposure to exercise and had more RV abnormalities post race.

via CW: More bad news for the (extreme) endurance exerciser.

Balance is the key here. Follow the link to read all of Dr. John’s synopsis.