We have all heard the terms HIIT and LISS when it comes to cardio. But which is more effective for fat loss and keeping gains? In this article, we take an in depth look at the differences between the two and which style will work best for your goals.
Table of Contents
What is HIIT Cardio?
High Intensity Interval Training (HIIT) consists of short, maximum effort intense sprints performed several times with rest periods in between. This is regarded as the most effective way to burn fat when it comes to cardiovascular exercise. A typical HIIT session may look something like this:
- 5 sets of 30 second 100% sprints with 2 minutes active rest in-between.
The key here is to make sure they are absolute 100% maximum effort sprints. The two to three minutes of rest in-between should be just enough to keep you from falling on your face from exhaustion.
The Science of HIIT
HIIT increases mitochondria biogenesis. What this means is that you are able to grow new and stronger mitochondria. Mitochondria are the “Power House” of the cells and improving them allows us to burn more fat. It will also enable us to improve insulin sensitivity, increase metabolic rate, and increase overall fitness levels.
HIIT has been shown to improve V02 Max which will allow you to train harder with more ease, and also recover faster between sets. This is very noticeable when performing weight training with supersets and drop sets.
What is LISS Cardio?
Low Intensity Steady State (LISS) Cardio is defined by moderate intensity (60%-70% of your maximum capacity) cardio over a period of at least 20 minutes. LISS allows participants to recover faster than more intense exercise and is a great option for beginners. An example of a LISS cardio session would be:
- 30 minutes jogging on a treadmill
- 20 minutes on an elliptical
- swimming laps
Studies show there are some key times when LISS cardio is very beneficial. The first is during periods of intense dieting. During this time, you will want to save some of your carbs and muscle glycogen for weight training. Too much intensity on cardio can leave you feeling fatigued for weight training. The other time would be periods of intense weight lifting. If your goal is maximum muscle gain (bulking), then LISS cardio will allow you to keep your cardiovascular fitness levels up without sacrificing muscle repair and rebuilding.
HIIT Cardio vs LISS Cardio
When comparing the two, it really comes down to your goals and preferences. If fat loss is your primary goal, then HIIT is what you are looking for. One study from the University of Western Ontario found that people lost more fat doing 4 to 6 30-second sprints with 4 minute rest periods than people doing 60 minutes of incline treadmill walking. That works out to 17 to 27 minutes of HIIT burning more fat vs 60 minutes of LISS.
It can be debated which type of cardio will keep more of your muscle mass. One side will say that HIIT will keep more because you are only performing short bursts so the catabolic effect is much less. Others will say that HIIT will actually cause more muscle loss because it will be combined with 5 days of intense weight training on top of the cardio and the body never fully recovers. In the end, neither style will be a bad decision.
If you enjoy giving all-out effort then HIIT is for you. On the other hand, if you enjoy a nice leisurely jog around the neighborhood, LISS is going to work for you. Remember, doing what you enjoy is more likely something you will stick to and be consistent with. Either way, cardiovascular exercise is an extremely important part of a healthy lifestyle and whichever style works for you, stick with it!
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