Cardiovascular exercise strengthens your heart, burns calories and releases endorphins. Doing as little as 30 minutes each day has the similar effect of an antidepressant, without any side effects.
A recent study in the UK showed that doing as little as 5 minutes of walking can reduce the intensity of nicotine withdrawal symptoms when quitting smoking. Cardio exercise does not necessarily have to be an intense run or an hour on a machine. Doing simple things throughout the day to get your heart rate elevated for even a short amount of time has significant benefits.
5 minutes here and 10 minutes there can add up to quite a bit of time by the end of the day or week. Not having enough time to devote to exercise, or not being able to run is a common excuse given for not including cardio into daily life. However, neither a large amount of time nor the ability to run is necessary to improve your health. When cardiovascular activity is incorporated into your lifestyle you will begin to look and feel better. As a result you will feel motivated to do even more. Start small and see what happens.