Also called aerobic or endurance exercise, cardiovascular exercise is any form of activity that uses aerobic metabolism. That is, during the activity, oxygen is heavily involved in the cellular reactions that produce the energy necessary to sustain the activity. Your heart rate increases and you breathe more deeply to maximize the amount of oxygen in your blood and help you to use more oxygen efficiently. Hence, you feel more energized and do not get tired quickly.

Cardiovascular exercise is any vigorous activity that increases heart rate and respiration and raises oxygen and blood flow throughout the body while using large muscle groups of the body repetitively and rhythmically. Such activity progressively challenges your most vital internal body organs and improves the function and performance of the heart, lungs, and circulatory system. Cardio improves many aspects of health, including heart health, mental health, mood, sleep, weight regulation, and metabolism.

Actually, the heart becomes more efficient with every beat as it pumps oxygen-carrying blood, the lungs more effective in taking in oxygen, and the muscles more equipped to use more oxygen. Still, like the breathing and heart rate increase, the surge is should not be so much as to make you feel that you need to stop and rest. In the course of cardio such as speed walking, cycling, swimming, running, or speed climbing, if you experience a strong urge to stop and rest unusual pain, or alarming symptoms, then you have to stop immediately and seek medical attention.

But for an exercise to be considered cardio, it must raise your heart rate and breathing rate into the moderate to vigorous intensity level (at least 50-percent of the normal rate) for a minimum of 10 minutes. That is why activities are undertaken to improve strength, such as resistance exercise, using weight machines, lifting weights, and core workouts are NOT considered as cardio because they do not raise the heart rate throughout the period of exercise.