Genes can help determine if people have a probability of getting a disease, such as heart disease. This doesn't mean that those who have a high chance of getting heart disease can't take measures to prevent it - studies have found that exercising can help reduce the risk of genetic heart disease. Researchers found that individuals who had a genetic susceptibility to heart diseases but displayed higher levels of physical activity, grip strength, and cardiorespiratory fitness showed a reduced risk of those diseases. Researchers state that those who have a high genetic risk should not be discouraged from excercising and that even if you don't have a genetic predisposition, you should still excercise.
I think it's important to live a healthy lifestyle whether a person is genetically susceptible to a disease or not, but especially if they are. A healthy lifestyle can certainly help minimize any disease or health concerns, so studies like this should be taken into consideration by many.
Original Study: Circulation