The study is the first to suggest that a simple exercise programme has an effect similar to that of the stem cells, when they are cajoled into producing new tissues through special shots.

Strenuous exercises includes running or cycling each day for half an hour, enough to work up a sweat, the European Heart Journal reports.

A study on healthy rats showed that an equivalent amount of exercise resulted in producing more than 60 percent of heart stem cells, usually dormant in adults, becoming active, the Telegraph reports.

After two weeks of exercise the mice had a seven percent increase in the number of cardiomyocites, the beating cells in heart tissue.

The John Moores team said they would now study the effects on mice which had suffered heart attacks to determine whether it could have an even greater benefit.

Georgina Ellison, from the John Moores University, who led the study, said, The exercise is increasing the growth factors which are activating the stem cells to go on and repair the heart, and this is the first time that this potential has been shown.

We hope it might be even more effective in damaged hearts because you have got more reason to replace the large amount of cells that are lost, Ellison added.

Although some patients with severe heart damage may not be capable of intensive exercise, Ellison said a significant number would easily be able to jog or cycle for 30 minutes a day without risking their health.

Jeremy Pearson, professor and associate medical director of the British Heart Foundation, which funded the research, said, However, much more research is now needed to find out whether whats been seen in this study can be translated into treatments for human patients.