Not only does exercise improve your health, even if you have already been diagnosed with something, but it can go a long way to prevent the onset of several life-threatening conditions, such as heart disease, diabetes and cancer. And exercise can make you look great - younger, fitter and thinner. Who needs any more convincing?

Think about it. A 30-minute walk every day can probably do more for your health than all the efforts of a dozen doctors and ten different types of medication.