You know you should do it. You know can be a boon to health. You know it involves sweating. But beyond that — what is cardio exercise exactly? How does it affect the body differently from other forms of exercise? What counts as cardio and what doesn’t? How often should you do it, and how should you do it? We have the answers below.

What Is Cardio?

“People tend to think of cardio in terms of steady state exercise, like jogging,” “But really, cardio is anything that

  1. A) raises your heart and breathing rates,
  2. B) improves the function of your heart, lungs, and circulatory system.”

To bring more clarity to this type of exercise, let’s tackle a few common cardio misconceptions one at a time:


Cardio is any exercise that increases the heart rate

Not quite. Just about any physical activity you do can increase your heart rate, from lifting weights to strolling between your desk and the bathroom to rolling out of bed in the morning. For an activity to qualify as a cardio workout, it has to meet both criteria mentioned above. In short, it has to raise your heart and breathing rates, and challenge your cardiovascular system, just like a biceps exercise has to challenge your biceps and an abdominal exercise has to challenge your abs.

While leisurely activities like walking and easy bike riding have benefits of their own, and are cardiovascular in nature, they aren’t cardio exercises (unless you are very de-conditioned). That’s because they don’t challenge the heart and lungs enough to improve their function.

Benefits of Cardio

What is cardio good for, and why should you bother doing it? Like brushing your teeth and sleeping for seven to eight hours a night, it’s one of the most indisputably healthy activities you can do.

By challenging and strengthening your cardiovascular system, you increase its capacity to take in oxygen, pump blood to the working muscles, and clear carbon dioxide and other waste products from your system. Plus, as your heart becomes more efficient at pumping blood, your resting heart rate slows, reducing the stress on your most vital muscle.

Long story short: cardio helps your heart and lungs function better both during exercise and at rest.