LISS cardio: What is it and why is everyone talking about it?

Liss cardio: Here's what you need to know about this latest fitness trend

LISS cardio is trending on Instagram. Another day, another workout acronym, and now we’re intrigued. So what do we need to know?

LISS cardio, you say. What’s that, then? It stands for Low Intensity Steady State and is essentially the slower, more measured younger sister of HIIT. ‘It’s the opposite of High Intensity Interval Training,’ explains Alex Adams, Certified Strength and Conditioning Coach and personal trainer at Performance Pro London. ‘So instead of you pushing your heart rate to it’s maximum in the traditional cardio sense, you take a slow and steady approach, keeping your heart rate at below around 60% of its capacity.’

According to Adams, it’s not a particularly new technique but thanks to it’s Insta-friendly name – coined by Australian #fitspo sensation Kayla Itsines and her partner Toby of Kayla Fitness – it’s gone big. Check out #LISS on Instagram for more.

What type of exercise does it involve? Relaxed walking, very gentle cycling, slow swimming, using the cross-trainer, some forms of yoga. Anything that keeps your heart rate at a slow, steady state for a long period of time, and nothing too frenetic and fast-paced.

Is it actually any good? ‘It’s great for improving recovery if you’ve done a lot of high-intensity exercise,’ says Adams. ‘It also buffers stress and promotes blood flow. Plus, it keeps your metabolic activity steady and intake of oxygen balanced.’ If your sport is running or swimming, for example, you would probably need to slow down your usual pace to get these benefits. So it's good for natural slow coaches.

And the downsides? ‘I don’t see as many fitness benefits as high-intensity workouts, if I’m honest,’ Adams admits ‘You would have to spend a long time doing LISS cardio – like, two hours or more per workout – to see fitness results or weight loss.’

Why is everyone obsessing over it, then? The truth is, it depends on your level of fitness and exercise regime of choice. As Adams says, ‘If you’re training six times a week, or you’re a marathon runner or Tough Mudder fanatic then LISS is great for recovery in between hardcore sessions. It’s also perfect for anyone just starting out with exercise to help build stamina or somebody who’s had an injury because it’s very low impact on the joints and ligaments.'

And who’s it not for? ‘Anyone who wants to seriously improve their strength, speed or change their body shape and burn fat would be better with high-impact exercise,’ says Adams. You burn far less calories with LISS, so it really depends on your goals and your workout style.