We want results, and we want them yesterday. There’s not point putting in the hard work, only to find out there was a better or faster route to take us to our goal.
Before we begin the debate, let me explain what each of these acronyms stand for and what each entail:
HIIT: High Intensity Interval Training cardio
Performed with a ‘work’ and ‘rest’ interval period requiring you to work at around >80% of your max heart rate in work periods (how to calculate your HR below) and 40-50% of max heart rate in the rest period. In order to produce the hormonal response (stress) required to make HIIT effective, it’s imperative to push ourselves to elevate our heart rate and induce that ‘out of breath, I’m dying’ sensation - soz. The ‘rest’ period can be active or inactive rest (i.e if we’re doing intervals on the treadmill, the work period will be set at a level in which we’re sprinting, and the rest period would be a slow walk). HIIT shouldn’t be performed for any longer than around 20-30 minutes, as if we’re working close to our max heart rate, we shouldn’t have enough energy in the tank to go for any longer than this - if we do, we probs aren’t working hard enough.
LISS: Low Intensity Steady State cardio
As the name states, this is cardio performed at a low intensity over longer periods of time. I suggest a minimum of 30 minutes for LISS cardio, and personally prefer it being done outside in nature (better for stress management) - however machines also ensure we’re consistent with our pace. For this zone with the goal being fat loss, we want to be in the 60-65% of your max heart rate. When I’m not outside walking, I like to get my LISS done on the treadmill, stair master or X-Trainer.
Calculating Heart Rate
220 - your age
E.g 220 - 29 = 191
So for LISS 60-65% of your max heart rate would be 114-124
I use my Fitbit to track my heart rate
Alternatively you can go old school and count your BPM (beats per minute)
(BPM = Find your pulse on your neck or wrist with your index and middle finger, count for 20 seconds and x by 3)
Now we’re all on the same page about what’s what, let’s talk about the pros and cons of each cardio method:
EPOC - excess post-exercise oxygen consumption, meaning our metabolism functions at a higher rate of burned calories for many hours after the session (as in we burn cals just chillin’ watching me on YouTube after your HIIT session)
Shorter duration for more calories burned - 3 times the amount of fat loss in half the exercise time of LISS
Variety - there are many different variables you can play with to keep HIIT interesting and make the time fly - I’ve put one workout at the end of this blog for ya babes
Increase cardio vascular capacity
There is a significant amount of stress placed on the body to get through a HIIT session, so recovery is vital, otherwise the positive effects will be reversed
Recovery time between sessions is larger due to the energy required to complete a session, most people need 2-3 days between sessions for recovery
Frequency due to these factors should only be performed 2-3 times a week
Low impact - body can go for hours and not get worn out
Increases aerobic base which filters through to a greater ability to withstand more intense cardio and weight training
Great for all training levels
Doesn’t require specialist equipment or knowledge
Can be used on rest days whilst still promoting recovery between weight sessions
The body becomes efficient - the more cardio we perform, the more efficient our body becomes as burning calories, aka our ability to burn calories slows down as we adapt, so walking for 30 minutes won’t burn as many calories in week 1 as it would in future sessions (so we need to ensure we’re increasing the duration - but we can only do this for so long. Walking for hours on end? Ain’t nobody got time for that)
Isn’t efficient at burning calories - Minimal EPOC meaning we only burn calories DURING our session, not afterwards
So as you can see, both HIIT and LISS have their place in training for fat loss. My advice, and preference from experience getting lean AF for my competition is using a combination of the two. I like to progress my cardio, so if I’m in a 12 week fat loss phase I might do something like this:
Cardio progression in a 12 week fat loss phase
Phase 1: 3 x 30 minutes LISS cardio per week
Phase 2: 3-4 x 45 minutes LISS cardio per week
Phase 3: 3 x 20-30 minutes HIIT cardio per week
Phase 4: 2 x 20-30 minute HIIT + 2 x 30-45 minute LISS per week
Now it’s time to put these words to good use and go get some cardio boo! I’ve written 5 sweaty little HIIT workouts for you to get done - you can thank me later + curse me throughout :) Let’s HIIT it!
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