You can’t change your genes, but you can fight off the effect of the heart disease genes passed down to you.

One of the biggest risk factors for having a heart attack is having a parent that had one, especially if it happened when they were young.

To some, this may mean avoiding exercise, believing genes “are what they are” and they will get heart disease no matter what.

But a new study in the American Heart Journal Circulation suggests just the opposite is true.

Researchers say if you are at high risk based on your family history, being physically fit can decrease your risk of having a heart attack or developing atherosclerotic disease by 49 per cent.

Also, exercising can decrease your risk of getting a very common arrhythmia called atrial fibrillation by 60 per cent.