Physical inactivity results in as many premature deaths as smoking! Adding exercise has been shown to reduce heart disease. You can reduce your risk if you do 30 minutes of moderate exercise 5 days a week or a total of 150 minutes a week. This can lead to a 14% risk reduction This can be as simple as brisk walking. If you up the duration to 1 hour, then your risk reduction is improved to 20%. Most authorities recommend the 30 minutes or 150 minutes a week.