Simply put, the term aerobic means “with oxygen.” When you're doing aerobic exercise, you need to use oxygen to convert your body's stored fat into energy to fuel your body's movements. Activities that are rhythmic, that require moving the large muscles of the lower body, and that are sustained over time are usually aerobic. When you exercise aerobically, you condition your heart, lungs, and circulatory system. You improve your body's ability to draw in, deliver, and use oxygen and to rid itself of carbon dioxide and other byproducts from the energy production process.

Contrary to what you may think, you should not be breathless when exercising aerobically. In fact, during cardio-training, you should be breathing comfortably and be able to speak a few words. Typical activities that are aerobic include walking, jogging, cycling, swimming, and dancing. Even housecleaning can be done aerobically, if you do it with gusto and keep moving continuously.

To improve your aerobic conditioning, you need to regularly stress your body by challenging it to perform continuous rhythmic activities. Aerobic training programs are designed using the elements of frequency, intensity, and time. In other words, you need to determine how often during the week you're going to train, how hard you're going to work when you train, and how long you need to train during each session.