Everyone’s banging on about HIIT – and for good reason. The question is: What is HIIT exactly? What are the benefits of HIIT? Is HIIT suitable for everyone? And how often should you be doing it? We address everything you need to know about this workout phenomenon.
What is HIIT?
High intensity interval training (HIIT) involves alternating between short bursts of intense activity at your maximum heart rate (how high it can go safely) and periods of low intensity recovery or rest.
Sessions can vary from 10 to 45 minutes.
Benefits of HIIT:
While benefits have been exaggerated in the past, there is no denying that HIIT has a place in nearly any balanced training program. Here’s why:
It’s super efficient.
A study published in the Applied Physiology, Nutrition, and Metabolism journal found that just 10 minutes of HIIT training equated to the same number of calories burnt in a 50-minute session of low-intensity steady state cardio (LISS).
Boosts metabolism and increases calorie burn.
The reason HIIT is so effective is because it produces excess post-oxygen consumption (EPOC), which raises your resting metabolic rate for twenty-four hours or more (some say up to 48 hours) after your training session. Meaning, you continue to burn calories at rest after smashing out a short, sharp training sesh.
The boost to metabolism directly correlates with the duration and intensity of a workout: in a study published in the Journal of Applied Physiology, subjects who completed 20 bouts of one-minute sprints (105 per cent of VO2 max), reported almost double the EPOC when compared to those who completed 30 minutes of continuous steady-state cardio. In other words, the harder you work, the greater the results you reap.
You’ll shed fat, fast.
Tabata (a form of HIIT) cardio protocols are some of the most effective cardio efforts if fat loss is your primary goal. Simply pick a cardio activity and complete a max effort for 20 seconds followed by 10 seconds of rest. Repeat seven times. Teamed with a fast-paced walk before brekkie, this will see you burning some serious cals.
What’s more, HIIT stimulates the production of human growth hormone (HGH) during the EPOC phase, and HGH is responsible for increased calorie burn.
According to Jungle HQ Owner Jack Boon, training at a greater intensity for short bouts will stimulate the activity of your beta-2 receptors, which sit on top of fat cells and react to adrenaline to accelerate fat loss.
‘Stubborn fat is far more insulin sensitive than normal fat; therefore, keeping carbs low and utilising fasted low-intensity cardio can be extremely effective. Fasting lowers insulin and naturally produces catecholamines, or fat burning hormones,’ says Boon.
One study published in the International Journal of Obesity found that while both HIIT and LISS showed significant improvements in cardiovascular fitness, 20 minutes of HIIT performed three times per week for 15 weeks was associated with significant reductions in total body fat, subcutaneous leg fat and abdominal fat among the young females tested. This was compared to the same frequency of 40-minute steady-state sessions.
Essentially, HIIT provides epic bang for your buck if fat loss is your goal.
It has anti-ageing benefits.
As much as we are advocates of showing off your happy lines, HIIT can help give you a more youthful appearance. Regular exercise, particularly high intensity training, can help stave off the ageing process by rebuilding cells that deteriorate with age.
A recent study published in Cell Metabolism put three groups of people on three different training programs: high intensity training, strength training, and strength training combined with high intensity training. It was found that the group who did high intensity training had better insulin sensitivity and an increase in the production of proteins necessary for muscle growth at a cellular level.
You’ll have healthy hair.
High-intensity bursts of exercise at full effort (enter trusty Tabata) will dramatically improve blood flow circulation to the muscles and surrounding skin. Improved circulation will provide nutrient-rich blood to hair follicles, according to Boon.
The caveat: muscle gain
A fast workout is a good workout, right? But keep in mind that sticking to high-intensity sprints or long jogs around the block won’t get you much stronger – you need to incorporate programmed resistance training into your routine to build lean muscle.
Boon suggests doing three to four weight training sessions per week, teamed with one or two cardio sessions such as a HIIT workout or low-intensity cardio for best results.
Is HIIT for everyone?
HIIT is suitable for everyone – from beginner to advanced. For a beginner, Founder and Head Coach of Highlite hi-tech Fitness Mark Hebblewhite advises having an appropriate workout prescribed and building up to higher intensities. HIIT for beginners might involve something as simple as a 30-second run followed by 15 seconds’ rest; repeated until you can’t continue.
Should you perform HIIT every day?
In today’s fast-paced world, we’ll all do what we can to fast-track results. That said, you need to give your body time to recover following intense training.
‘Recovery is just as important as your training sessions for maximising results. If you are training at high intensities at maximum efforts, you shouldn’t exceed two to three training sessions per week at that level,’ says Hebblewhite.
‘If you exceed that recommendation, you should reduce the intensity of the training on the additional days to allow your body sufficient time to recover. A good way to measure intensity levels is to track your heart rate with a heart rate monitor.’
This helps you plan a variety of intensities in your weekly training program.
While high intensity training is important for improved fitness, it can be detrimental to train hard every day. Your body requires time to recover and to produce the desired physiological adaptations.
The right balance of intensity will vary between individuals, but it’s recommended to include mobility exercises and stretching before you begin, which are vital for recovery and injury prevention.
Need one more reason to love HIIT? You can do it anytime, anywhere. Whether you’re enjoying a nice Sunday at the beach, you’re away on business, or you’d like to stay active while on holiday, try our head trainer Alexa Towersey’s beach HIIT workout.