It is no surprise the whole fitness world has been taken over by HIIT - or variations of HIIT for many years now. These high-intensity interval-training sessions ask for 100% effort of quick bursts of exercise, a format that promises to torch away calories within a short period of time. Examples of HIIT classes can be a military-style bootcamp class, workouts with Tabata, or a session that involves functional style training or even Crossfit.
The formula of high intensity chunks punctuated by short breaks promises to give you a big pump of adrenaline and surge of energy. The length is usually about 30 to 45 minutes offering time efficiency - being able to burn a high amount of calories in a short period of time which lowers body fat, heart rate, blood pressure and of course speeds up your metabolism. We will not forget to mention the endorphins - get ready to be transported to a pretty euphoric place post-session. Benefits aside, there is no denying that it is vigorous. So come prepared to be really challenged. Studies have also shown however that HIIT boosts cortisol (stress) levels and depletes your adrenal glands if done extensively. Of course the intensity of the movements itself also can end up injuring people - so tread carefully. Take with you a bottle of water, a ton of motivation and some serious commitment.
LIIT on the other hand, is low-impact interval training. Workouts are structured the same way as HIIT ( intervals and short breaks) but the big difference is how high your heart rate is brought up. With HIIT, your heart rate is taken into a high cardio zone (maximum or almost maximum) whereas with LIIT, you reach the low end of that cardio zone, which is known as the fat burning zone. This means the peak inside a LIIT class is at a lower intensity level. Barre, Pilates and Power Yoga can all be considered LIIT classes.
Make no mistake - staying in the fat burning zone with LIIT also well - burns fat. It is not necessary to only burn fat in a cardio zone as with HIIT. This is great news of course as it allows you to reap the benefits of an interval training, but without having to push your body into the extreme. If your LIIT classes are done correctly, you will still burn the same amount of calories as with a HIIT class - providing you commit to at least 60 minutes each session. Low impact is of course beneficial for those recovering from an injury, those who have joint issues or perhaps someone who simply wants to go a little more gentle with themselves. It is also sustainable over the long run.
So whether you decide to go HIIT or to go LIIT, it is important to weigh the pros and cons based on what your body needs on that specific day & what your overall goals are. Remember, a good fitness routine is one that includes variety, so there is always the possibility of combining the two - if it calls to you, that is. Happy Training!