If you’ve ever been to a gym or thought about starting to exercise you’ll have heard about cardio or CV training, which usually means running on a treadmill, cycling or some type of aerobic work. But few people have any idea that CV stands for cardiovascular and those that do aren’t really sure what it means. Below I’ll explain more about this, what it actually is, how it works and how it will benefit you whether your goal is getting a six pack, losing weight or just increasing your fitness.
What Does CardioVascular (CV) Mean?
When someone in a gym says they’re going to do some CV or cardio, what they mean is they are going to train their cardiovascular system, which in this context means to work their heart, lungs and circulatory system. Basically this is any type of exercise that is focussed on increasing the heart and breathing rate so that over time the body adapts to do this more efficiently, similar to how muscle adapts to resistance training. The adaptations are different for each part of the CV system.
The heart is made of cardiac muscle. It is composed of two halves, left and right, and has two chambers on each side. The lower chambers are the ventricles, while the upper chambers, which are smaller, are the atria. The job of the ventricles is to pump the blood around the body, first to the lungs to be filled with oxygen and then back to the heart to be sent to the rest of the body. The job of the atria is to fill up with blood for storage in between heartbeats, which is kept away from the ventricles by valves. The valve on the right is called the Tricuspid Valve and on the left it is the Bicuspid or Mitral valve.
So the right side of the heart receives all of the blood after it has made its journey around the body and then contracts to send it to the lungs. The left side of the heart receives oxygen-rich blood from the lungs and contracts to send it around the body. Each contraction makes the sound that is your heartbeat, and what you can feel if you put your finger on your wrist or neck to take your pulse is the blood rushing through the veins and arteries with each one.
The purpose of the lungs is to extract oxygen from the air and get it into the blood, which at the same time is cleansed of the carbon dioxide that comes from activity within cells. The process starts with air entering the body via the mouth or nose, passing through the larynx at the back of the throat and then down the trachea (windpipe). The trachea then splits into the left and right bronchi that in turn split into increasingly smaller tubes in the lungs called bronchioles, all of which have alveoli at the end.
The alveoli are tiny sacs which resemble a bunch of grapes, surrounded by equally tiny blood vessels called capillaries. It is here that the bloods oxygen and carbon dioxide gas exchange takes place before it continues around the body as part of the circulatory system.
The Circulatory System
Blood travels around the body via blood vessels, of which there are two main types: Arteries carry blood away from the heart while veins carry it towards the heart. Arteries divide into smaller vessels called arterioles and then further still into tiny capillaries, allowing them to reach into tissue cells. This is where oxygen is delivered and carbon dioxide is picked up. Now on its way back to the heart the blood travels through capillaries that now begin to merge into larger vessels called venules, which in turn merge to become veins. Veins are the equivalent in size of arteries, but they have a slightly different structure.
The whole circulatory system can now be described starting at any point, in this case the right ventricle.
right ventricle –> pulmonary artery –> lungs –> pulmonary vein –> left atrium –> left ventricle –> aorta –> body tissue (except lungs) –> vena cava –> right atrium
Training CV Or Cardio
Now that you have a better idea than most of what it actually means to do your CV training or cardio, all that’s left to know is how to do it. This depends on your personal goals but basically anything that causes your body to require more oxygen than at rest will do. This is because the lack of oxygen causes your breathing rate to increase to obtain more and your heart rate to increase to deliver it around the body. Done regularly your heart gets stronger and your lungs get more efficient at this so they don’t need to work as hard to meet the demand, especially at rest. This is why the fitter a person is, the lower their resting heart rate will be.
Typical types of CV training or cardio include things like jogging, cycling or rowing, done at a steady state or high intensity intervals, but resistance training can also have the same effect. Combining the two in the form of circuit training helps to train the muscles as well as the cardio system, but the type you choose depends on your goals as well as which one keeps you motivated and gets the best results. Also try to find something you enjoy doing as you’ll then be far less likely to come up with excuses not to do it!
As always, any questions or feedback leave a comment below.