Exercise reduces the risk of heart disease even if people are considered to be at high genetic risk of the condition, the results of a new study indicate.

Researchers looked at over 482,000 people in England, Scotland and Wales, who were aged between 40 and 69. Those with no signs of heart disease were monitored over the course of around 10 years.

The study found that exercise, particularly cardiorespiratory exercise, appeared to outweigh genetics when it came to heart disease, lowering the risk of the condition irrespective of whether a person was at low, medium or high risk.

"Genes don't have to determine destiny. You can impact your risk by being more fit," insisted the study's lead author, Dr Erik Ingelsson, of Stanford University in the US.

The participants' activity levels were monitored via questionnaires, grip strength measurements and other tests.

"It was a very consistent pattern for all of these different measures. All were associated with lower risk of disease in the future," Dr Ingelsson noted.

The study looked specifically at the genetic profiles of those at highest risk of heart disease, and atrial fibrillation (AF), which causes irregular and rapid heartbeats.

It found that those who were at the highest risk of these conditions, but who also had the highest levels of cardiorespiratory fitness, reduced their heart disease risk by 49% and their AF risk by 60%.

Commenting on the findings, Dr Russell Pate of the University of South Carolina, said that this is an important message for the public.

"You can't eliminate genetic risk, but you can absolutely attenuate the effects. This research is added ammunition in making the case that promotion of physical activity deserves a prominent place in public health," he said.

Details of these findings are published in the journal, Circulation.