Beginner’s Guide to LISS (Low Intensity Steady State): Exercises for Newbies
WHAT IS LISS?
Low Intensity Steady State (LISS) is a form of cardiovascular exercise which, as the name suggests, is performed at lower ‘intensities’ than other types of exercise. When we talk about exercise intensity – at least in regard to cardiovascular activity (cardio for short) – we’re talking about intensity in relation to our heart rate.
Your maximum intensity for cardio is when your heart rate is at, or near, its maximum. Imagine sprinting as fast as you can until your heart feels like it’s about to explode and you can no longer continue. Low intensity cardio is a heart rate ‘zone’ which is much lower than this level of effort!
A simple calculation to work out your predicted maximum heart rate is 220 minus your age. If you’re 30 your maximum predicted heart rate would be around 190 beats per minute. From this point, you can work out your different training zones.
- Very High Intensity Anaerobic Zone = >85% max heart rate
- High Intensity Zone = 70-85% max heart rate
- Low-Moderate Intensity Aerobic Zone = 50-70% max heart rate
- Very Low Intensity Aerobic Zone = 40-50% max heart rate.
WHAT HAPPENS TO YOUR BODY WHEN YOU PERFORM LISS?
Each zone above uses a different ‘dominance’ of fuels to sustain the level of intensity required. Although they’re all forms of cardio, they impact your body in different ways and have some differences in the adaptations they cause.
At higher intensity zones, your body mainly uses glucose (blood sugar) and glycogen – a storage form of glucose you ‘top up’ by eating carbohydrates. The reason for this is because glycogen can be used to produce energy without the need for oxygen – hence ‘anaerobic’. This is what happens when you work so hard your body can’t deliver sufficient amounts of oxygen to your muscles to keep up with the energy demand.
When this happens, your body can’t ‘access’ all the fuel available in glycogen and this incomplete ‘metabolic process’ starts to produce compounds that impair performance. This is why you can’t sustain activities at high intensity for long durations.
However, if you lower the intensity and work at lower heart rates you can provide enough oxygen to totally use up the fuel in the glycogen. And as you don’t get a build up of these chemicals, you don’t have to stop as quickly and can maintain moderate intensity outputs.
Unfortunately, your body’s glycogen reserves are finite. An average person holds only about 500g and this is enough to support around 2000kcal of activity. When this runs out you hit what marathon runners call ‘the wall’. Basically, you can keep going but as you have run out of glycogen you have to rely entirely on your body’s biggest fuel reserve – stored body fat.
Although fat stored in your body is high in energy – 9kcal per gram compared to 4kcal for glycogen – it actually takes more oxygen to create energy from fat. This means you have to be working at lower intensities, or forced into working at lower intensity, when glycogen stores run out, to use your fat reserves.
In reality, during cardio you rarely rely on one single fuel source. It’s more of a sliding scale of ‘glycogen dominance to fat dominance’. It’s only at the extremes of intensity, very high or very low, that you only use a single fuel source.
WHAT ARE THE ADVANTAGES OF LISS?
For the reasons outlined above, LISS is known as your fat burning zone. However, this is a bit misleading. Although fat is the primary energy source the overall effect on fat loss isn’t better than other intensities of cardio when calorie expenditure is matched.
There are some complex mechanisms at play here, but ultimately weight loss comes down to creating a calorie deficit and increasing energy expenditure by doing physical activities you enjoy. This is where LISS really comes into its own.
Although it doesn’t use up lots of energy in a short period of time, LISS is much easier to sustain. This means you usually have to do it for longer than other forms of cardio to burn the same number of calories. However, LISS is also much less taxing on your body so you can do it more frequently and for longer durations fairly comfortably. This makes LISS an ideal form of exercise to build a ‘fitness base’. Especially for beginners!
LISS has been shown to help regulate a healthy weight, encourage weight loss as part of a calorie controlled diet, improve cardiovascular and general health. It’s something you can do every day, even without specialist equipment, by simply performing activities of daily living, like walking, at a brisk pace to reap the benefits.
ARE THERE ANY DRAWBACKS TO LISS?
Well, not anything that would be seen as really negative. It might not be as efficient at burning calories as higher intensity exercise or promote the same levels of performance ‘adaptation’ an athlete might require. And it certainly won’t build muscle like resistance training. But on its own it will have no negative impacts on overall health.
However for athletes, or those wanting to build muscle, you need to structure training accordingly and LISS alone will not be sufficient to meet these demands.
LISS is a great way to increase energy expenditure to help lose or maintain a healthy weight alongside helping to promote a healthy heart and general well-being. It is typically gentle on your body and can be performed for long durations and frequently.
It might not be ideal for some people, taking up a bit more time than other methods, or not creating the right adaptations for optimum performance or muscle growth, but for beginners looking at being a bit fitter and healthier and building a solid ‘base’ it is a great place to start.