All available information shows that rates of cancer are a lot lower in people who take regular exercise. Regular exercise will also reduce the risk of other serious conditions such as heart disease and strokes. For most people, thirty minutes of vigorous exercise a day, at least five times a week, is recommended. The exercise should be strenuous enough to leave your heart beating faster, and you should feel slightly out of breath afterwards. Examples of vigorous exercise include going for a brisk walk, or walking up a hill.