Simply put, the term
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.
When you exercise aerobically, you elevate your heart rate. The result of regular aerobic training over time, however, is a lower heart rate, both at rest and when you're working. This lower heart rate means that your heart is stronger and working more efficiently.
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.