You might have seen a previous post that I did about the benefits of cardiovascular training which is a great place to start because anything that raises your heart rate is going to be beneficial to your cardiovascular system.

There’s so much more to cardiovascular training however and I’m going to discuss the biggest 2 right here for you, you lucky people.

You might have heard people talking about HIIT (high intensity interval training) but have you heard about LISS (low intensity steady state)?

Chances are you might not have heard about it but you’ve more than likely done it before. When you’ve decided that the 3 doughnuts you’ve eaten today were a bit much and you’re going to go to the gym and jog on a treadmill? LISS. When you dare to bare your pale skin for a gentle session at the pool for the first time this year? LISS. When you decide that you’re going to be healthy and go for a long walk ending up in a not-so-healthy pub lunch? LISS. Basically, if you can hold a conversation whilst training, you’re doing LISS.

The benefits of this kind of training is that because you’re normally working at 60-80% of your maximum heart rate, you’re comfortably within the ‘fat-burning zone’ which means that you’re burning a higher percentage of fat within the energy that you’re using.

Think of it like a cake. At this stage, the energy that you’re burning is the size of a cupcake (stick with me, don’t get distracted by the thought of cupcakes) and a majority of that is fat.

LISS is therefore good for:

- Unfit or elderly people who want to lose weight but need a low-impact form of exercise to protect their bodies

- People who have the time to go out walking for a couple of hours or jog for an hour, it’s pretty time-consuming!

- Endurance athletes (marathon runners, triathletes etc.) who need to get their bodies used to working at low-intesity for long periods of time

- Anyone who wants to unplug for a while, force themselves to not look at a screen and enjoy the great outdoors

There’s one big flaw with LISS though. Whatever your goals are your body will need to keep adapting otherwise your progress will plateau. If you just do LISS you will reach that plateau quite quickly as the body finds it easy to adapt to and then gets very comfortable.

Have you heard that story about the person who went to the gym 3 times a week, did the same workout each time including a 20 minute run on the treadmill and 15 minutes on the stationary bike? Do you remember when they stopped going after a few months because they stopped losing weight? They should have done some HIIT.

Which bring us to HIIT (funnily enough). HIIT covers any kind of cardio exercise that combines periods of near-maximum work with periods of recovery. It can be applied to most forms of cardio including running, cycling, swimming, skipping, boxing etc. and includes things like tabata and circuit training. For example, you could warm up, then sprint for 30 seconds followed by a recovery period at a jog for 1 minute and then you could repeat that as many times as you like before you cool down/pass out.

HIIT will bring your heart rate up into the moderate/intense training zone meaning that you’ll be improving your aerobic fitness and overall performance. In these zones you’ll be burning a higher proportion of carbohydrates than fat but don’t be fooled, you’re still burning plenty of fat.

Let’s go back to the cake idea (focus now…). With HIIT the cake is now Bruce Bogtrotter-sized (if you don’t get this reference then shame on you, go and read Matilda right now).

The amount of calories from burning carbohydrates and fat is much higher than what you’ll burn through LISS meaning that you’ll probably burn more fat overall. It’s a smaller percentage of the cake but the cake is so much bigger with HIIT. Makes sense?

Here are some of the benefits of HIIT:

- Great for time-poor people, you can squeeze a brilliant workout into whatever time you have available, even as little as 7 minutes if necessary, and keep your heart rate up

- It keeps the body adapting because your heart rate is going up and down with periods of work and recovery and your body doesn’t know what’s coming next

- The ‘after burn’ effect or excess post-exercise oxygen consumption (EPOC) from HIIT keeps your metabolism high after exercise meaning that you continue to burn calories when you’re lying in your post-gym bubble bath. Result

- HIIT allows you to keep any muscle mass (within reason) as it uses muscles to their maximum capacity, keeping them working. Think about a sprinter’s physique vs a marathon runner

- The explosive nature of HIIT will help you to increase the strength in your muscles which in turn could improve your endurance performance - a good point to remind endurance athletes of the importance of cross-training

It might seem like I’m leaning towards HIIT as the preferable form of cardio but actually, I believe that both LISS and HIIT have their roles in fitness depending on the individual and their goal. Ideally, a combination of both would help to improve overall cardiovascular fitness and health and to reach personal goals.

Try including a few sprints next time you go running and reap the benefits!