I see a lot of questions circulate around the internet about whether HIIT (high intensity interval training) or LISS (low intensity steady state cardio) is better.
First, I want to make it clear that you first should determine what your goals are before choosing which option you would like to stick to.
Now, let's get into it...
HIIT cardio is anything where your heart rate reaches around 70-90% of your maximum heart rate. HIIT is typically done in a short period of time because you are running at a pace that cannot be sustained. With HIIT, you do have short rest periods where your heart rate will drop and you will spike it back up again with your interval. For example, performing a sprint, burpees, jump squats, and more.
With HIIT cardio, you will burn more calories in total due to the fact that you will continue to burn calories once you are finished, with LISS you will not. This is called post exercise oxygen consumption. HIIT will also ensure that the lean muscle that you have is preserved and not lost through hours of cardio.
This all sounds great right?
But, there are some downsides to HIIT. For example, you should not perform HIIT daily. Not only will this not allow you to fully recover, but this can also lead to overtraining. This can increase risks of injury, not to mention, there will be a couple of sessions (if performed at this 70-90% intensity range) where your form may be compromised due to fatigue. HIIT is recommended 3-4x per week for around 15-20 minutes.
LISS is a cardio that is performed at around 50-70% max heart rate. LISS is typically done for a longer period of time and is less intense. Think marathon running, incline walking, or an activity where a conversation can still be held. LISS is aerobic, whereas HIIT is anaerobic. LISS cardio does burn lots of calories when doing a long cardio session, however it will take you longer to burn those calories when compared to HIIT.
However, LISS is something that can be done daily, and not only is is great for cardiovascular health, but it is also shown to be amazing for fat loss. Many times, it is very easy to recover from low intensity cardio, and if you have any type of knee pain, back pain, etc. then LISS cardio may be the better option for you. With LISS, you are using the fat stored in your body as a primary source of energy instead of glycogen. LISS cardio may help you burn fat more effectively than high intensity workouts.
Now, what do you think after comparing these two?
I highly recommend implementing both into your training plan and seeing how you perform. Let's say, starting with 1 HIIT session and 2 LISS sessions per week. Also, depending on your goals. Bodybuilders and endurance athletes will need a completely different protocol. Someone who is looking to gain a ton of muscle vs. someone who is on a weight-loss journey will need a completely different protocol.
The main thing that I tell others is to find something you can stick to, that is easy to maintain within your weekly schedule. Next, closely monitor how you look, how you feel, how sore you are, how your performance is in and out of the gym and go from there!