What is Cardio?
Cardio (CV, Cardio Vascular) exercise strikes fear into beginners, but why? Its easy to think of hours spent on the treadmill, but there are many ways to get your cardio in. Before we look at a few examples of cardio, lets take a look at what it is and how it works.
Cardio vascular exercise is a term used to describe the efficiency and fitness level of your heart and lungs, and their ability to transport oxygen to your muscles as they work. There are lots of complicated processes going on in your body to allow this to happen, but that shouldn’t mean it’s difficult to understand. Let’s take a look at the different parts of the cardio vascular/respiratory system and see how they work in harmony with your body when you work out.
Your heart is definitely the most important part of your CV/R system. A car wouldn’t get very far without an engine, and this is yours. The heart is what allows all the cells in your body to get their oxygen and make their energy in order to move, stay warm and repair themselves, by pumping blood from the lungs to all of your muscles and cells, so it’s easy to understand that we need to look after it, just like a car in many ways, if you don’t service it regularly or run it without the things it needs, it will break down. We don’t want that to happen!
The lungs are also very important for your CV/R fitness. Did you know that when you’re breathing normally, you don’t use anywhere near the full capacity of your lungs? When we breathe, all of the air is filtered inside of the lungs, the oxygen is used up and the rest is exhaled! Thanks to a clever chemical in your blood, the oxygen simply sticks to it and is then pumped around by the heart until it gets where it’s needed. Through consistent cardio training, you can make your lungs better at doing this, and become healthier, fitter and stronger.
Your blood is also responsible for the efficiency of your CV/R system. The blood is made up of many different things, but the ones we use for our fitness are the red blood cells. The red blood cells take the oxygen from your lungs, and drops it off at the muscles and other places it’s needed. Because your body is able to adapt, you can produce more of these cells and become even more efficient at transporting the oxygen and increase your physical capabilities.
So how do we measure it? There’s a term called ‘VO2 Max’ which is used to determine your Cardio Vascular fitness level. Sounds complicated right? It’s actually really simple, all it means is the Maximum Volume of Oxygen that you can use. It’s measured in millilitres per kilogram of bodyweight per minute, so if your VO2 Max was 55, and you weigh 100 kilos, you will be using 5.5 litres of oxygen every minute during intense exercise! Once you have measured this, you have a benchmark to measure your progression as you continue your training.
If we want to improve our cardio vascular fitness level, we have a number of options available to us. In the Energy Systems article, it mentions three different energy zones. These tie in with different training zones that come under the cardiovascular umbrella. These are fat burning, aerobic, and anaerobic. These three training methods have slightly different effects on your body, and training each one will give you a greater level of all round fitness. Let’s take a look at the different training zones in more detail.
The Fat Burning Zone.
This is a prolonged low intensity method of exercise. Your heart doesn’t have to work very hard when it’s in the fat burning zone, and you can breathe normally too, but how does it work? When we ask our muscles to do any form of movement they use the energy that we give them. In the fat burning zone, you don’t need to provide lots and lots of energy because the work load is low. What happens next is what gives this training zone it’s name. Converting stored fat back into energy takes a little while, so if you’re exercising at a high intensity, your body will want more readily available energy to use so that your muscles can keep working. When you’re in the lower intensity fat burning zone, you have got lots of time to convert those stored fat cells into energy to be used as your fuel. If you’re new to exercise, or just looking to lose a few pounds then this is a great way to get started. Examples of exercise in the fat burning zone could be a slow and steady jog, hill walking, or gentle swimming.
The Aerobic Zone.
The aerobic zone is a mid intensity level of exercise that will get your heart and lungs working. When you start to workout in this zone, you start to push the limits of the readily available energy supplies you have been using while in the fat burning zone. What this means is that you increase the requirement for oxygen and breathe harder and deeper as the intensity increases. Eventually you will get to a point where you feel like you can’t go on anymore and you will feel that all to familiar hot build up of lactic acid in your muscles. This is know as the lactic threshold, and this is what aerobic training will help to increase. As you do this type of workout more and more, your body will become more efficient at transporting and using the oxygen you breathe in, and as a result you will be able to run further, faster and for longer than before. It’s a great way to increase your overall fitness level and one that can be measure reliably with a VO2 max test, such as a bleep test, the rockport walking test or the cooper test.
The Anaerobic Zone.
The anaerobic zone is a very high intensity level of exercise, and often the heart will be working close to its maximum potential so please consult a Dr before undertaking such intense levels of physical activity. The anaerobic zone requires lots of energy in a very short space of time, and like the energy systems article explains, when there is no time for you to use the oxygen you breathe, you will use your creatine phosphate system. This is the kind of high intensity workout zone that professional athletes will use in order to further their top end physical fitness, and increase their storage of creatine in the muscles. Some examples of anaerobic exercise would be HIIT (High Intensity Interval Training), Hill sprints, and some spinning classes will dip into this zone too. It’s a great way to push your fitness to the next level as a part of a well structured program, and will reward you with fantastic results. If you haven’t already, have a read of the energy systems article and find out more about how they work together.