The Case of Cardio Cracked

The Case of Cardio Cracked

What is cardio?

Cardiovascular, shortened to cardio, is a term used to describe the circulatory system that consists of the blood vessels and heart within the body.

When you “do cardio”, you are completing an exercise that raises your heart rate and helps to strengthen this network, while also increasing your metabolic rate. Your metabolic rate pertains to your metabolism which is the complex structure of chemical processes in the body that are needed to sustain life. Therefore, metabolism refers to how your body breaks down and uses certain substances for energy. When you exercise, you need more energy and therefore your metabolic rate (the rate at which your body breaks down said substances) is increased.

When you have a strong cardiovascular system, it means that you have more capillaries bringing in more oxygen to your muscle cells. When this happens, your body is able to burn more fat when you are active (exercising) and also continues to burn fat even when you are inactive (at rest).

In simple terms, cardio is endurance exercise that increases your heart rate and results in more blood being pumped throughout your body. If your heart rate reaches 50-75% of its maximum rate, this can be classified as a cardiovascular exercise. To give you an idea of how to calculate an estimate of what your maximum heart rate should be, start with the number 220 and minus your age. So, for example, if you are 25 years old, this will be worked out as follows:

220 – 25 = 195 beats per minute should be your maximum heart rate. Going above this may result in heart issues.

This is not intended to serve as an absolute figure or accurate calculation for everyone, because there are also a number of contributing factors such as blood pressure and any pre-existing health concerns that need to be taken into consideration when ascertaining how far to push your body when exercising. However, the above formula does help you to get an idea of what your maximum heart rate should be and is therefore a good guideline for generally healthy individuals.

It is a common misconception that cardio is merely running, walking or cycling. In fact, any exercise that increases your heart rate whilst utilising large muscle movements over a sustained time period can be classified as cardio.

There are a number of reasons why cardio is so good for you, and a few reasons why too much of it can be detrimental. Some people believe that cardio does not build muscle and try to avoid it at all costs unless they feel the need to cut down on fat and lose weight, and others only perform cardio exercises when working out.

The cardio debate is one that has been going on in gyms and fitness studios since the first stride was taken on an elliptical. It is because of this that the following article unpacks and explores the many sides to cardio, its pros, cons and more. So, if you are looking for an end to the so-called never-ending argument, then put down the weights, step off the treadmill and take a read. We have done our research, we have asked the right questions and now we have the answer...

Women running

Cardio cracked open

Why is cardio good for me?

Cardio can help you to shed that extra weight

The more you move, the more calories you burn. Because cardio consists of constant movement, it can often burn more calories than weight lifting. This is because when you are lifting heavy weights, you normally have breaks in between sets to give your muscles a little break.

Some people ‘overdo’ cardio and tend to lose more weight than expected as too much cardio can result in excessive weight loss. The trick to achieving a slim, toned physique is to balance weight lifting and cardio.

A good idea is to bring in HIIT cardio – this stands for High Intensity Interval Training. What this basically refers to is pushing yourself and your heart rate to the maximum at given intervals, and then resting for a specific amount of time afterwards. You can change the period of time in which you push yourself and rest according to your fitness levels. But the idea is that you burn more fat in a shorter amount of time through raising and dropping your heart rate intermittently. Some people prefer HIIT as opposed to same-pace extended cardio sessions as these can sometimes be drawn out and boring.

With HIIT you will be focused on pushing yourself and then trying to get your breath back in a short resting period. An example of HIIT cardio is sprinting at maximum effort for a minute and then resting for two minutes, then sprinting again for a minute. You repeat this cycle about five times – as stated, it all depends on your own fitness levels and you can work up to this if you battle to complete five rounds initially.

Quick note: If you are unable to complete a sentence properly during exercise, then you are pushing yourself too hard.

Cardio exercises your heart

Many people forget that your heart is an actual muscle that needs to be exercised. If you do not exercise it, like any other muscle, it will get weaker.

Thus, your heart needs to be constantly exercised in order to stay healthy and improve oxygen flow to your body. This allows you to operate at optimal performance in your daily life.

Cardio creates a strong circulatory system

When you exercise, the cells in your body need more nutrients and oxygen in order to keep you going. When you do cardio, this delivery system is strengthened as it allows the heart to increase blood flow and reinforces blood vessels. This means that your cells get more nutrients delivered to them.

If you think about your cardiovascular network to be a series of streets, when you are unhealthy and do not exercise, these streets can become congested and backed up with cars (plaque build-up within arteries). When you exercise, these streets become wide lane highways with delivery trucks gliding through to deliver oxygenated blood and nutrients.  

Woman on treadmill

Cardio can make you smarter

You that read right. Cardio can in fact make you smarter. A study was done that examined how those who exercised regularly had stronger hearts which were able to pump more oxygenated blood to their brains. Researchers then compared these people to those who did not exercise and therefore had weaker hearts. When looking at the group who did not exercise, they noted that their brains had less nutrients and oxygen which resulted in them aging faster and their brain functionality being compromised.

Cardio makes you happy

When you exercise, your body releases endorphins. These are known as ‘happy’ hormones as they enhance your mood and can help ease depression.

Cardio means better sleep

When you do cardio, you have exercised your body, released endorphins and possibly frustration from your daily life and this, in turn, allows you to have a better night’s sleep. That means that when you hit your pillow after a long day, your body has released excess energy through exercise, while nutrients and blood flow have been increased and so your body is ready to rest more effectively.

Why do people say too much cardio is bad for you?

After having discussed the many wonders of cardio, it is only fair that we explore the other side of the spectrum and dive straight into the downfalls of cardio:

Too much cardio can be detrimental to your heart and health

Chronic cardio has been shown to cause plaque build-up, stiffen your arteries and even result in heart dysfunction. This was found in a study done on strenuous runners who were completing ultra-marathons and ironman triathlons. Many of these endurance runners suffered from cardiac (heart) issues, one of these issues was a weakened right ventricle.

Although recovery was evident a week following their races, the conclusion made was that intense and sustained cardio can be detrimental to the way our hearts function, causing significant physical stress when pushing them too hard through strenuous endurance training.

Too much cardio can result in weight gain

When performing chronic cardio i.e. extremely gruelling cardio over a long period of time, it can have a negative impact on your hormones. If you are pushing your body too hard and putting your body under stress, your body will release cortisol – the ‘stress’ hormone.

This hormone is not a bad thing in small doses, however, when it is consistently released, it can sabotage your health as the hormone tells your brain to store more fat than needed and hinders your body’s ability to process sugars. This results in weight gain. So, if you find that cardio is making you fat, and you’re not eating more calories to compensate for the deficit created by this exercise, then this could very well be the reason.

What is the difference between cardio and strength training?

By now you should know that cardio does not mean that you have to spend hours on a treadmill or cycling until your knees give in, but it is simply exercising to a point where your heart and metabolic rate is increased. We will now look into the difference between cardio and strength training.

Cardio decreases your inflammatory signalling in the fatty tissue, while also preventing your body from storing too much fat, as long as you are sticking to healthy doses of cardio. Cardio also builds endurance as it strengthens your body’s circulatory system.

On the other hand, strength training uses resistance exercises that contract your muscles in order to build muscle. While cardio may burn more calories during a workout, strength training in itself results in a metabolic spike after a workout, this means that calories are burned even after the workout.

Through balancing your cardio and strength training, you will be able to burn calories, lose excess fat and gain muscle. The more muscle you have, the more calories you burn throughout the day.

So, cardio and strength training ultimately go together like salt and pepper, mac and cheese, bread and butter (although probably not the food pairings you should be thinking of while reading an article on working out 😉) – they are a classic combination for building a lean, toned physique.

What do cardio and strength training have to do with weight loss?

When comparing strength training and cardio with respect to weight loss, many people say that cardio is the way to lose weight and strength training is the way to gain muscle. However, the reality is not so simple. There are a number of schools of thought on this subject, in order to properly unpack these, we will first look at what kind of exercise is likely to burn more calories.


In reality, cardio and strength training burn equal amounts of calories, but what it all comes down to, is how each one is performed. When you are performing high intensity training (HIIT), such as sprinting on a treadmill, you are running for half of the time and resting for the other half – depending on your work to rest ratio. To explain this simply, if you are sprinting for one minute and then walking for two, your ratio is 1:2. The same thinking goes for when you are lifting weights. You burn the calories when you lift the weight, but then you have resting periods in between.

However, many people spend more time resting during a heavy weight training session than they do when walking or running on a treadmill which often results in fewer calories being burned after a strength training workout as opposed to a cardio workout.

Earlier we mentioned how your body continues to burn calories after you have lifted weights, this is known as EPOC – Excess Post-Exercise Oxygen Consumption. This also impacts the number of calories burned from a single workout. So, if you opt for a weight training workout, it needs to be one that is intense in lifting, with just short periods of rest between sets.

Both cardio and strength training have the potential to burn large numbers of calories and yield great results, depending on how they are performed. However, cardio tends to rack in the higher numbers when it comes to calorie burn due to the fact that most people have fewer rest periods in between intervals.

Weight loss

When you are looking to lose weight, personal trainers and studies have found that through combining cardio which helps shed fat with weight training, which helps build muscle (also, remember that muscle weighs more than fat), you are likely to achieve the best results. However, the biggest finding after these studies were conducted was that what people ate impacted their fitness levels and body goals more than the type of exercise performed.

To help you to remember this concept, “food before fitness” should be a saying you keep in mind before embarking on any sort of health journey. This means, get your eating healthy and portions correct first, as unhealthy and excessive eating habits can quickly unravel all of the hard work you put in during those gym sessions.

The verdict

The controversy surrounding cardiovascular exercise and how it should be done generally arises due to people not understanding what exactly cardio is. As stated, it is any form of exercise that increases your heart rate over a sustained period of time. This can be done through running, rowing, walking, stepping and even weight training. Cardio is generally good for you.

Obviously when we say that, we are not talking about the type of cardio engaged in by endurance runners who have developed heart issues through chronic cardio-based exercise and overexerting their cardiovascular systems, we are talking about good, healthy doses of cardio.

There is no doubt about it. Cardio exercises your heart, improves circulation, blood flow and nutrient supply. It also improves carbohydrate intolerance and reduces insulin resistance. It can result in a happier and healthier you, however, too much of a good thing can also be detrimental. It all comes down to balance and finding the workout combination that works for you.

Also, remember that your body is an ever changing and adapting system, and so is your metabolism.  So, if all you are doing is stepping on the treadmill at the same speed and interval every single day without changing a thing, then your body is likely to adapt and hit a plateau and you are unlikely to see any results.

However, if you combine cardio with strength training, you are bound to see some rather satisfactory results. However, if cardio is your cup of tea, then have a look at our article on running for weight loss. 

To help you along, we have laid out some cardio and strength training exercises for you to do in the next section: 

What cardio exercises can I do?

Step off the treadmill and do these instead!

The following exercises combine cardio (so get ready to get your heart rate up) with strength and resistance training to get intro great shape!

Kettlebell swing

Kettlebell swing

This is a great and explosive cardio exercise as it targets powerful and large muscle groups – focusing on your quads and glutes while also pumping up your heart rate. It is important that you get your form right for this exercise in order to avoid injury.

How it’s done:

1 – Hold the kettlebell with both hands, palms facing towards you. With your knees slightly bent and your feet shoulder-width apart, shoulders down, with a slight arch in your back, look forward with your chest up. The kettlebell should be between your legs. Choose a weight that is challenging to swing but still allows you to keep a good form.

2 – Grip the kettlebell, you are going to swing it now. Keep your arms loose and long and you retract your shoulder blades and engage your core. Soften your knees and shift your weight onto your heels, as you bend your hips, squeezing your glutes as you now swing the weight up in front of you. Try to stop the swing when your arms are straight in front of you, at a 90-degree angle to your body.

3 – Once the weight has swung up in front of you, let it swing back down between your legs as you bend your hips. Reverse the momentum to complete the next rep.




An all-time military favourite (and yes, we can hear the groan as you read this), these are a great way to engage your muscles and burn calories. If you can do about seven a minute, you will get a great workout in!

How it’s done:

1 – Begin by standing with your feet shoulder-width apart. Your arms should be at your sides and your weight on your heels.

2 – Lower your body into a squat as your push your hips back and bend your knees.

3 – You will now place both hands directly on the floor in front of you. They should be placed just inside your feet. Shift your body weight onto them as your feet jump back into a high plank position. Do not let your back droop or your butt stick up, keep your body straight.

4 – Then jump back into position number two, being in a squat position with your hands between your feet.

5 – You will now reach your hands up into the air and jump up.

6 – From this jump, you will then land back into position number two. That is one rep.

Jumping rope

Jump rope

This is an awesome way to engage your legs and core whilst torching those calories and getting fit at the same time. A lot of people haven’t jumped rope since grade school, if this is the case, start without a rope and simply mimic the movement in order to get the hang of it.

How it’s done:

1 – Holding the rope in both hands, you will swing it over your head and create a rhythm.

2 – As the rope swings around, jump over it – landing on the balls of your feet with each jump. Engage your core on each jump.

3 – Try to land gently on your feet, jumping continuously for about a minute at a time.

4 - Shake things up a bit by jumping with one leg at a time and focusing on how high you can lift your legs and not how fast you can go.


Inchworm exercise

The previous exercises are by-the-book. So, we thought we would change things up and bring in an interesting exercise called the inchworm. Your core and arms are predominately used in this one.

How it’s done:

1 – Start with your feet shoulder-width apart and your core engaged throughout the exercise.

2 – Bend from your waist and place your hands on the floor in front of you.

3 – You are now going to begin to walk with your hands forward, as you keep your legs straight behind you into a high plank position. Engage your inner inchworm on this one and squeeze those abs!

4 – Keep your back straight, from the high plank position, walk back with your hands and return to a standing position. That is one rep.

Mountain climbers with a twist

Mountain climbers with a twist

Mountain climbers are said to greatly improve your core strength whilst engaging your upper and lower body at the same time. They are easy to get right and result in a fantastic cardio workout.

How it’s done:

1 – Begin in a high plank position. With only the balls of your feet and hands holding your body weight. Having your arms straight in front of you, hands pushing on the ground as your core is engaged and your back is straight.

2 – Bring your right knee in towards your left elbow, getting it as close to touching as you can. Ensuring you do not bounce your hips too much. Continue to alternate between legs.

3 – It will look like you are running in the high plank position.

4 – Try to do this for one minute at a time with a 30 second rest period between.

Disclaimer - is for informational purposes only. It is not intended to diagnose or treat any condition or illness or act as a substitute for professional medical advice.