Posted on March 31, 2022 by Harry Edwards

There has been a recent popularisation of HIIT or High Intensity Interval Training as the new go-to form of cardio for you to get into. But what is HIIT? Why is it getting such acclaim? Furthermore, what’s the point of cardio at all? It’s often people’s least favourite part of a workout, can we get by without it? In this article we will answer all these questions and more, covering what cardio actually is, how it benefits your health and fitness, and then different forms of cardio training for you to incorporate into your fitness journey.

What is Cardio?

Cardiovascular exercise, or more commonly “cardio”, refers to exercise which challenges the ability of the heart and lungs to take oxygen in and of the body to burn that oxygen to generate fuel for our muscles. When discussing cardio we typically mean exercises which involve moving our whole body or a large portion of it in a repetitive manner. Examples include running, swimming, rowing and cycling. This can be at differing levels of intensity, from a slow walk to a lung-bursting sprint, and will serve different purposes accordingly. But what is the benefit of doing cardio?

Benefits of Cardio

Cardio can be the least favourite part of some people’s workouts but it serves a very important purpose. As previously mentioned, cardio tests the heart and lungs. Besides perhaps your brain, these are the two most important organs in your body. Your lungs inhale the oxygen necessary for oxygenation of blood, which in turn is necessary for all actions within your body. Your heart then pumps that oxygenated blood to where it is needed and moves the deoxygenated blood back to the lungs to restart this essential cycle. As such, the lungs and heart are very very important! Like when you do a bench press for your chest or squats for your legs, cardio exercises these vital organs, improving their ability to perform their essential functions by forcing them to adapt to a new stress. As such regular cardio exercise is associated with a reduction in all cardiovascular health conditions and improvements in the functional capacity of the lungs during exercise as well as the cardiac output of the heart. It also provides benefits to your blood lipid profile, blood pressure, bone mass, and metabolic rate. It should also be noted that, like any other muscle, to neglect working out the heart and lungs will cause weakness in all the aforementioned areas, which is seriously bad for your health! In this way, cardio is a vital component of any fitness journey with a wide array of benefits.

Types of Cardio Training

Cardio can be performed in an endless number of ways. Some people like a continuous block, typically characterised by an aerobic curve in which people start from a low intensity, build up to a high intensity, and sustain the peak effort before gradually easing back to a lower intensity. This is how most people perform their runs or bike rides, be it 2K or 20 miles. Interval training is an alternative approach, in which you use distinct “work” and “rest” periods to break up your cardio. For example, you could have a 60 second working period followed by a 30 second rest period. You will then repeat these intervals for however long you want your workout to be. But what kinds of interval training are there?


High intensity interval training, or HIIT for short, is the most popular version of interval training. HIIT involves working periods in which you exercise close to or at your absolute maximum effort, going all out for a short period of time before getting a rest. This method of exercising is very time efficient, enabling you to break a sweat, get your heart pumping and burn those calories in a shorter period of time. Additionally it can be made specific for whatever your training goals are. Athletes for example will often have HIIT workouts designed to simulate their competitions. There is also some evidence that short-burst, high intensity exercise may be better at promoting weight loss than longer, less intense workouts. Another significant benefit is that HIIT, by being explosive and max-effort, promotes the development of muscle fibres that are better suited to explosive, dynamic movement. This transfers well to all sports and to many daily activities. As such, HIIT, unlike many other fitness fads, is actually really great and effective for whatever your fitness goals are! Be sure to incorporate it into your workouts or try it out in one of our Motive8 classes!


A less well-known form of interval training, low intensity interval training or LIIT involves less intense but longer working intervals followed by rest periods that are more active than those in HIIT. For example, one might go from a light running interval to a walk rather than from an all-out sprint to dead stop. This style of interval training takes a longer period of time to be effective, which can be unattractive for many exercisers. So why would anyone train like this? One reason is to reduce the impetus for adaptation in response to cardio while still getting the benefits for fat/weight loss. LIIT is often used by bodybuilders who want to avoid the catabolic effects of higher intensity cardio and use LIIT to reduce their body fat while retaining as much muscle mass and size as possible. Another reason one might use LIIT is if, due to age, injury or a health condition, high-impact or explosive movements are not possible. In these cases, LIIT provides a great way for people who might otherwise feel excluded from exercise to still reap the benefits. Finally, by being less stressful on the body, LIIT doesn’t require long periods of rest between sessions to recover from soreness and can be performed more consistently through the week as a result. However for the average person a standard aerobic curve-based workout or a HIIT workout will be, in my opinion, much more effective and rewarding. To find out more about optimising endurance exercise, check out this article by our very own Jenny here!

Get after it!

So now that you’re fully equipped with the knowledge on everything cardio-related, get moving! Whether its a walk, run, cycle or row, its all great for you! If you get stuck for ideas and want a bit more guidance on what kinds of cardio you should try, feel free to give one of the lovely members of staff at motive8 a shout at [email protected] . We’d be happy to help show you the way and get you on track for whatever your goals and dreams are! Thanks for reading and hope to see you soon!