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As the ABC launches the Your Move campaign to help Australians explore their health and fitness journey, reporter Marnie Vinall hits the road to try some of the growing exercise trends around the country.
As one of the most popular fitness trends going around, I thought I'd give high-intensity interval training (HIIT) a bench test.
Key points:
- HIIT sessions involve short, sharp bouts of exercise at maximum effort, with short recovery times
- The sessions include exercises such as tuck jumps, sit-ups, tricep dips and lunges
- Classes are often available at gyms and are touted as being convenient and time effective
This wouldn't be my first rodeo with high-intensity exercises.
During the six lockdowns of Melbourne, I went through a YouTube dance HIIT phase, where I would squat and jump along to Hamilton and Disney songs, blindly following a fitness YouTuber's instructions.
But this would be my first in-the-flesh group class – one where I couldn't decide to skip moves or exercise at my pleasure, or log off early deeming I had sufficiently already done enough.
This time, I'd have nowhere to hide.
As my local gym already offers these types of classes, I decided it would be a safe and convenient bet to road-test the popular exercise format.
But first I got in contact with John Hawley, director of the Mary MacKillop Institute for Health Research at the Australian Catholic University, to ask what HIIT was all about.
"High-intensity training and interval training have been around for years for athletes, but it's only recently that they've become popular for general health," he said.
The idea behind it is "very short, high-intensity bursts" of exercise followed by short periods of rest.
For example, 10 minutes of high-intensity work with one minute of recovery between each set for 20 minutes.
"Now, what is high intensity? Well, it's something that pretty much you can only do for a minute, and then you have to stop," Dr Hawley said.
It involves exercises like tuck jumps, planks, jump squats, jumping jacks, sit-ups, tricep dips and lunges — all aimed at increasing your heart rate to 80 per cent.
Dr Hawley told me these exercises had cardiovascular benefits due to the heart rate being greatly increased, while increasing strength to the muscles used from tension or resistance placed on them.
"You're getting a really good bang for your buck," he said.
"You're applying a very potent stimulus to remodel the cardiovascular and muscular system."
Furthermore, various research has associated HIIT with improved cardiovascular and metabolic outcomes, including increased fitness, weight loss and improved blood pressure and inflammatory markers.
So I took myself to the gym for a late afternoon HIIT class to see how I'd go with these short bursts of high intensity followed by – what I assume for me in my first go – ferociously sucking back in the oxygen.
The class was split into three sections with drink breaks in between. Each section lasted around 15 minutes and was filled with 45-second bursts of exercises, which ranged from high knees and bum kicks to burpees, squat holds and planks.
I started pretty confidently, grabbing a weight to hold during the lunges and then jogging on the spot between exercises but it didn't take long for the fatigue to set in. About 20 minutes in, I dropped the weight and just tried to keep up and push through the pain.
Although, 45 seconds had never truly felt longer than when doing glute holds or burpees interspersed with push-ups. I was thankful for the short breaks between exercises.
I was dreading another round of squat holds when the instructor declared, 'You did it!' and guided the room into a series of stretches before letting us go. These included runner's lunges, pec, hamstring and quad stretches and child's pose to release the back.
I was red-faced and sweaty but happy with my effort. The time did go quickly and I could see what Dr Hawley was talking about when he said it was an efficient form of exercise. My whole body, plus my cardiovascular system, felt like it got a workout.
So, I took my shaky legs home, going extra slowly down the stairs on the way out, and hopped straight in a warm salt bath as a reward.
Dr Hawley said for non-professional athletes, refuelling did not need a huge focus, but a big meal and plenty of water should do the trick.
Also, that he would recommend not only doing HIIT classes but combining them with other forms of training, such as endurance-type exercises like swimming, running or cycling. And to always try and get a cool down in to help remove lactic acid from the body and speed up recovery.
For now, I'm just going to focus on the recovery sleep.
What is HIIT?
HIIT stands for high-intensity interval training, where participants complete short periods of explosive exercise at maximum effort with very short periods of rest between — traditionally about 20 seconds on, 10 seconds off, although those timings do change and can extend up to a minute or slightly longer.
Those explosive exercise periods are done under anaerobic conditions, which basically means "without oxygen". That means you can't do it for as long as aerobic exercise.
As a result, exercise sessions of this type normally last about 30 minutes.
This type of exercise burns glucose and creates a build-up of lactic acid.
How much does a class cost?
HIIT classes are often combined with a gym membership or as part of a six- or eight-week pack, which can cost anything from $150 or $200.
Where can I do HIIT?
Gyms that offer HIIT classes are fairly commonplace — just search HIIT to find your nearest gym, or to find a class you like the look of.
Alternatively, a personal trainer may offer HIIT classes, just check their website.