What is LISS and what does it do for weight loss?

SBS series How To Get Fit Fast explores whether slow and steady exercise could actually win the race.

Can we really get away with a walk to get fit and lose weight? Source: SBS

LISS (Low-Intensity Steady State) exercise could well be bliss to the ears of the less-than-enthusiastic exerciser. Yes, we may in fact live in an alternate reality where exercising without busting a gut with the uber popular HIIT (High-Intensity Interval Training) may actually be ok.

But it’s a bit HIIT and LISS (geddit?) when it comes to conflicting opinions on which is best.

That’s where How To Get Fit Fast comes in, where presenter Anna Richardson sorts the wheat from the chaff as a guinea pig, investigating both exercise modes so you can decide which is best for you.

So what’s LISS, and what are its benefits?

While it’s being branded “the next big thing” in exercise, it’s pretty much been around as long as we’ve been bipedal. LISS is simply what we know as cardio: walking, swimming, running etc. but at a gentle and controlled pace.

For some, a steady exercise like a run with their pooch may be more appealing than a high-intensity one. Source: Supplied

“If you’re tracking your heart rate, you should aim for about 40% – 55% of your estimated maximum heart rate to sit in the LISS zone,” exercise physiologist Sarah King tells Sporteluxe. “This equates to a pace where you can comfortably carry on a conversation with someone, and your breathing is only slightly elevated.”

But despite it being around forever, exercise professionals and scores of media stories have ramped up touting the benefits of LISS recently.

And LISS has plenty to recommend it. It will likely be a more palatable option for beginners - take a gentle jog with the dog or tempt heart attack with 50 burpees? Hmmm. For many, getting over that psychological hurdle of just starting some kind of exercise is a great achievement.

There’s a lot to be said for just moving. According to the Australian Burden of Disease Study, released in 2017, diseases most closely aligned with physical inactivity include diabetes, bowel cancer, dementia and heart disease. It found that an extra 15 minutes of brisk walking at least five days a week would reduce the disease burden in the population due to physical inactivity by about 13 per cent. Increase that to 30 minutes and it would be reduced by 26 per cent.

LISS exercise may also better suit those with injuries and medical conditions, and is great for recovery between more intense exercise.

Beth Sheehan, accredited exercise physiologist and practice innovation advisor at Exercise & Sports Science Australia, argues that good exercise needn’t always be hard.

“People get so caught up in the fact that good exercise is exercise that has to be gym-based or strength-based or high-intensity, and that’s not the case,” she tells The New Daily.

And while HIIT gets all the credit for its efficient fat-burning capability, LISS shouldn’t be discounted on that front.

“Training at a lower intensity means that more oxygen is available to your body,” writes personal trainer and fitness entrepreneur Kayla Itsines on her blog. “As fat needs oxygen in order to be broken down, the more oxygen you can give your body, the more fat you may be able to burn.”

Itsines advocates a mixture of HIIT and LISS, and warns that only doing the latter can lead to your body breaking down stored muscle as you burn energy.

And personal trainer Mike Zhang argues at my body + soul that if you’re trying to lose weight, “LISS does have a tendency to deliver negligible results (read: weight maintenance not loss). If fat-loss is your goal, HIIT training that includes resistance work is your best bet.”

But then, exercise physiologist Dr Bill Sukala refutes that claim telling The New Daily that LISS could be “far better for building fitness and losing stored body fat” than a quick round of HIIT. The catch? You’d have to do LISS exercise for two hours.

So why go slow and steady when you can go hard and fast with HIIT?

HIIT - quick bursts of high-intensity exercise with short rest periods in between - is hugely attractive because of its efficiency in burning fat and improving fitness in a fraction of the time of a lengthy cardio session. Medical Daily reports that three 27-minute HIIT sessions a week will improve your aerobic and anaerobic capacity as much as doing five 60-minute cardio sessions a week.

Source: SBS

And HIIT also provides the added benefit of burning more calories and fat in the 24-hour period after your workout than compared to a steady session of cardio.

But you’ve got to be mentally and physically prepared to work mighty hard and fast with punishing exercises like burpees, jumping jacks, lunges, sprints, squats and planks, not to mention the higher chance of injury.

“Yes, HIIT is stressful. Your body doesn't really like working at a high intensity (usually defined as somewhere above 70 percent of your maximum heart rate),” writes fitness instructor Sam Downing at 9Honey Coach. HIIT workouts, he amusingly admits, can be “so brutal you want to scream four-letter words/vomit/die a merciful death/all of the above.”

And that physical stress from such intense exercise may not be good for everyone writes King at news.com.au, leading to “chronically high levels” of the stress hormone cortisol “which can lead to increases in blood pressure, weight gain around your waist, and a suppressed immune system.”

But surely some short-term stress and pain working hard and fast in our time-poor lives are worth it over slow and steady cardio in the quest to lose weight?

Join Anna Richardson and co-presenter Amar Latif from the steady-state comfort of a seat somewhere to decide for yourself. How To Get Fit Fast airs on Monday 30 July at 8:30pm.