Credit: Edgar Barreira(Flickr)

A new study suggests that strenuous exercise appears to stop the body's cells from killing themselves as they're programmed to do.

Researchers found that cells of people who had just run a marathon didn't engage in what is called apoptosis -- the natural death of cells.

Apoptosis is a normal physiological function dependent on a variety of signals, many of which can be modulated by strenuous exercise. Here, we've shown for the first time that exercise modulates expression of the sirtuin family of proteins, which may be key regulators of training, says study lead author Gabriella Marfe, of the University of Rome.

Marfe and colleagues took blood samples from 10 male athletes who'd taken part in a 42-kilometer run and found a shift in the balance between expression of pro- and anti-apoptotic genes after the race.

The researchers think that proteins in the sirtuin family may play a protective role in preventing cell death through exercise.

Marfe with a word of caution says that  Untrained amateur athletes often do hard training without professional advice. Such intense and exhaustive exercise can be harmful to health.

The authors recommended to gain better benefits, exercise should be part of a lifelong regimen with expert medical advice and supervision.

The study was published May 10 in the journal BMC Physiology.