Posted on August 18, 2022 by Harry Edwards

Do you feel gassed out when you run, row, cycle or swim, or do you get out of breath during your day to day activities? This is a common malady that gym goers want to get rid of. It’s one of the most common areas of desired improvement, often classified under the trusty old, “I just want to get fitter”. But what is the best way to do it? What exactly does improving your cardio mean? In this article we’re going to explore what our cardiovascular system is, and how best to increase it’s performance for great cardio.

What is the cardiovascular system?

The cardiovascular system refers to the network of veins and arteries powered by the heart that pumps blood around the body. This is tied to, but technically separate from, the lungs which we typically associate with our cardiovascular ability. In order to have good cardiovascular fitness, you need a number of qualities working in tandem with each other. First and most importantly, your heart needs to be sufficiently strong to pump blood around your body to provide sufficient oxygen to your muscles as they work. Like any other muscle, your heart can be “worked out” or “trained”. As it adapts to new stresses and pressures, the amount of force it can generate in a single heartbeat increases. This means it can push a larger volume of blood in a single beat and increase the efficiency of the circulatory system as a whole. However, even the strongest heart will eventually have to increase its work rate in order to keep up with increasing physical demands. As you become fitter, the upper limit of your heart rate will increase, allowing you to work out at higher intensities while still receiving enough oxygen to continue working. This constitutes the majority of what is considered the cardiovascular system or cardiovascular fitness, with stroke volume and heart rate being the two most important factors.

The lungs do also play a key role. After all, what good is a hyper-efficient circulatory system if the organ responsible for getting oxygen into the body isn’t working properly? Mirroring the heart, the lungs’ efficiency can be judged by tidal volume (the amount of air inhaled and exhaled in one breath), which improves as fitness levels increase, and breathing rate (number of breaths in a minute), which increases as the demands placed on the body become more intense. These factors will contribute to how efficient the overall cardiovascular system is, acting as the pump which supplies the circulatory system with the oxygen it transports.

What does this have to do with “cardio” fitness?

“Thanks for the anatomy lesson Harry…”, I hear you say, “…but what does this have to do with me feeling puffed out when I run?” Well, the reason you quickly get tired when you run is because one or more of these factors is not sufficiently developed, meaning that your cardiovascular system eventually is unable to keep up with the demands placed on the system. As you work harder and harder, eventually oxygen is not available in the quantities necessary for normal burning of glycogen for fuel. Instead, glycogen is broken down more inefficiently without the presence of oxygen, causing lactic acid to be produced as a by-product. This accumulates in the muscles until you are unable to continue exercising. “So if that’s what’s happening, how do I improve my cardiovascular system to avoid this happening or delay it?” Fear not dear reader, the answers are not far away!

How to improve your cardiovascular fitness

So, the simple answer is keep doing your cardio! Your body is exceptionally good at adapting to different pressures and circumstances. If you keep exposing yourself to a particular stress, assuming you are properly fuelled and allow yourself sufficient time to rest and recuperate, your body will optimise itself to best perform the task you’re making it perform. However, if training was as simple as “just keep doing X”, personal trainers would be out of a job!

Firstly, establishing a strong foundation of cardiovascular fitness is initially achieved through performing Long Slow Duration Training. This involves covering more distance than you’re aiming for (or longer than “race distance”) but for a longer duration, typically from 30 minutes to 2 hours. This should push you to somewhere in the range of 70-80% of your VO2 Max and be performed once or twice per week until you can comfortably complete your workouts. Then you can progress to interval training. This should be specific to what your goals are. For endurance, intervals should have longer working periods and shorter rest periods. For power or explosivity, short working periods and longer rest periods are ideal. It is vital that you closely monitor your rest periods. Too much rest and you will not receive sufficient stress to prompt an adaptation, while too little rest and you will be unable to complete the workout and will eventually become over-trained. For some more top tips on implementing cardio effectively into your training, check out the link here!

Example Workouts

Maybe some examples would be helpful! Imagine you were wanting to get in shape for a 10K run. A quick, streamlined version of your preparation might look like this:

Building your foundation

15 kilometre run – 65-75% intensity – No specific time limit – Emphasis on good running form – Should be able to comfortably speak throughout

12 kilometre run – 70-80% intensity – No specific time limit – Emphasis on good running form – Communication is slightly limited while exercising

Increasing Intensity

Once you have completed one or two weeks of training with the previous LSD runs, you can begin implementing interval runs.

The average person can complete 10K in 50-70 minutes, so this template will be based upon these figures, however they can be adjusted to suit your specific needs.

3 Minute Intervals – 3 minutes trying to cover as much distance as possible – Rest for 3 minutes – Repeat for a total of 10-15 rounds

2K Intervals – Run 2K as fast as possible – Rest for 5-10 minutes – Repeat for a total of 5 rounds

It’s all about specificity my dude!

So this is how you could prepare for a 10K run, but as previously mentioned these principles can be applied to any form of cardio over any distance. The more specific your training is to whatever you are preparing for, the more your body will be adapted to it and able to perform at a high level. You could prepare for a 10K run by doing loads of swimming, it would have some benefit for your cardiovascular fitness, but it would be much more productive to do lots of running training supplemented by S&C work that targets the primary muscles involved in running.

Whatever you’re preparing for, fun runs, charity swims, you name it, the key is to start slow and long distance before graduating to higher intensity intervals. This is the secret to great cardio! For more examples of workouts that centre on cardio, check out the links here and here! Motive8 is looking to assemble teams for a series of charity events including the Abbey Dash 10K, so come on down to Marshalls Court to get involved in our 8 week runners S&C sessions to implement some of this training into your fitness journey and meet new people with the same drive and goals!