top of page

The cardio conundrum

It's a common misconception that we need to to hours of cardio to lose weight. Treadmills are literally running hot by all the New Year resolution folks joining a gym in January, most of which are on a mission to run off the mince pies. If this is your preferred means of going from a sedentary to a more active lifestyle, bring it on! However, cardio alone doesn't magic away the extra kilos, particularly if there is no shift towards a calorie deficit and a healthier diet.

Benefits of cardio

Cardiovascular fitness is you body's ability to take in and use oxygen for physical demands. Essentially, how well your lungs are working, how effective your heart is pumping blood and therefore oxygen out to muscles, and how your muscles utilises this oxygen. There are plenty of obvious benefits to improving our cardiovascular fitness:

  • Lower risk of heart disease

  • Lower blood pressure

  • Lower resting heart rate

  • Improved circulation

  • Stronger lung function

  • Improved muscle tone and muscle mass

  • Improved bone density

  • Can help lower fat mass

  • Improved sleep

  • Stress-relief

A pretty impressive list that shouldn't go unnoticed, as all of the above helps us live a long, healthy life. However, if running any longer than to the bus, or if you have injuries that stops you in your tracks, cardio is so much more than running. And it doesn't have to take hours, either. First, let's cover the many types of cardio yo can do, all of which will help achieve the above benefits. Do make sure you go at a pace where you get somewhat out breath to help improve your heart and lung capacity:

  • Running

  • Walking

  • Cycling

  • Swimming

  • Cardio machines (elliptical, stairmaster etc)

  • Rollerblading or iceskating

  • Skiing

  • Dancing

  • Bodyweight exercises at pace

  • Weight-bearing exercises at pace

Most of these can be defined as 'LISS' - low intensity steady state training', at a heart rate between 50-65% of max. You typically do LISS activity for 30-60 minutes, so there is more of a time commitment. I'm a big fan of the latter two options though, as you may have realised by know that I'm a big fan of strength training - AND you can get great results with these, in a much shorter timeframe, which is a win for busy parents.

High intensity resistance training (HIRT)

You have probably heard about HIIT (more on that below), which is an excellent form of cardio, but given that Stronger By Siri is all about making you stronger and more confident, pay attention to HIRT! It is what it says on the tin - resistance training (using equipment, but bodyweight works too) performed at a high intensity. High intensity in this context refers to the resistance and tempo - the pace of which you do the exercise and how much rest you get - i.e. doing short bursts of resistance exercises with short rests in between. Intensity also refers to the resistance you are working at; more weight generally provides better results - given that each and every rep can be performed with good technique. Which is crucial.

This type of exercise is often structured as a circuit for a full-body workout, but can also be more focused, say on upper or lower body only. You can argue that HIRT provides the above cardio benefits in a supercharged way - you will see these improvements faster, particularly when it comes to weightloss and improvements in the muscle vs fat mass ratio - in favour of more muscle mass, less fat mass. Another major benefit? Time. LISS-style cardio is often shunned for the time-poor amongst us, but with a HIRT workout can be done and dusted in 15-30 minutes. It is two birds in one stone, as it's a combination of strength training requirements and cardio requirements. It is all in the planning though, and being confident that your technique that is spot on to avoid injury.

High intensity interval training (HIIT)

Let's cover HIIT whilst we're at it. HIIT exercise is also commonly structured in a circuit-style, but primarily (not exclusively) using bodyweight exercises. A HIIT class generally leaves you out of breath and in a sweaty mess, which can feel ah-mazing. Think burpees, box-jumps, squat jumps and sprints at 80-95% of max heart rate in 20-30minutes and you're done. It wins over LISS in the time category, and you will see cardiovascular capacity benefits at a more rapid rate compared to doing LISS. However, because of its 'go hard and go home'-manner, it puts a lot of stress on the body and technique is often compromised, which can lead to injury or incorrect movement patterns.

Both HIIT and HIRT provide plenty of variety, which keeps things interesting and helps you get away from just favouring the muscle groups you're 'good at' working out. We are creatures of habit and we do need to get out of that comfort zone to progress. I see huge confidence boosts in clients who have gone from hugging the cardio machines in the gym to learning to confidently lift weights. Both HIIT and HIRT can be done in a short space of time, AND provide results faster than steady-state cardio. Finally, a big plus for both in regards to weight management is their positive influence on your basal metabolic rate (BMR) which you can read more about here.

Which type of cardio should I choose?

The million dollar question! To which the answer (as always...) is: It depends. I would stay LISS is a great place to start - particularly if you are new to exercise, or returning to exercise from a long period off (due to injury, having a baby or work has taken over your life). Before going down the HIRT road, be sure to learn how to lift weights with good technique,. In fact, the same applies to HIIT, as you're 90% certain to do a burpee, which can quickly fall flat on its face (literally) if done incorrectly.

If you don't consider yourself a beginner and are injury free - give HIIT or HIRT a try! I would personally favour HIRT due to the many benefits resistance trainings provide, particularly for women, and the time aspect is a major plus in my book. Variety is key, so alternate between the different types of cardio and strength training that you do, to keep things interesting and fun. In the end of the day, the best exercise is the one that you will enjoy and consistently come back to for more!

Further reading / references:

High Intensity Resistance Exercise Training vs. High Intensity (Endurance) Interval Training

High-Intensity Interval Resistance Training (HIRT) influences resting energy expenditure and respiratory ratio in non-dieting individuals

Everything you need to know about heart rate and HIIT

High intensity resistance training: HIRT for home workouts


bottom of page