HIIT: What It Is & How To Do It
We get it. Finding the time to work out can be hard. For those of us who are always on-the-go with work, family, or just life in general, the faster we can get it done, the better. That’s where high-intensity interval training (HIIT) can help.
You might be reading this if you are currently on your own fitness journey right now and want to find a program that is right for you.
You’ve more than likely heard the term HIIT thrown around at the gym, or amongst friends that you work out with. So, what exactly is high-intensity interval training, what are the benefits, and can it really maximise your training efficiency if you are short on time?
- What is HIIT?
- How are HIIT workouts structured?
- What are the benefits of HIIT?
- Who can do HIIT?
- Examples of HIIT
- How to get the most out of HIIT
- Getting started with HIIT
- Alternatives to HIIT
What is HIIT?
Designed to push you to your limits, high-intensity interval training (HIIT) has become a popular training choice for anyone who wants to get maximum results in little time, while working towards their fitness goals.
This fast-paced training style is typically between 20-45 minutes and involves short, intense bursts of exercise. These exercises often use bodyweight, but can have added weights, like a kettlebell, dumbbell or medicine ball, and are followed by either active or complete rest. HIIT workouts will make you sweat and keep your heart rate elevated the whole time!
For example, you will complete as many reps as you can of an exercise for a short period of time, typically for 20-30 seconds, then rest and continue onto the next exercise with only short breaks in between.
The idea is to work at your maximum effort. This is usually around 85% of your Maximum Heart Rate, which is the maximum number of times your heart will beat in a minute without you going beyond your limits.
For you to complete HIIT and get the full benefits, you need to push yourself every round!
How are HIIT workouts structured?
The most common form of HIIT is performed for 20 ‘on’ 10 ‘off’ — 20 seconds of work and 10 seconds rest. However, the recovery time can last as long as the work time. The recovery, if not complete rest, is usually performed at 40%-50% of your maximum heart rate.
Any type of cardio exercise can be done as a HIIT workout — including cycling, skipping, running or rowing. Simply set a work interval and rest period to get started.
SWEAT Trainers Kayla Itsines, Chontel Duncan and Kelsey Wells include high-intensity workouts in their programs and while these workouts follow different styles of high-intensity training, they all give your whole body an intense workout!
Some of the most common high-intensity training styles include:
This training style involves 20 seconds of maximum effort, followed by 10 seconds of rest for a certain number of rounds. Typically, a traditional Tabata workout is eight rounds of each exercise, however this may vary in different training programs.
Chontel includes Tabata training alongside AMRAP in FIERCE, which includes six to eight exercises for two to three minute bursts, separated by 60 second rest periods.
Circuit training is effective as you can target a variety of different muscle groups. It works by rotating between different exercises, repeating them at least once. You then either complete a number of reps of each exercise in the circuit, or you perform the exercise within a set timeframe, before moving onto the next.
There is only a short rest after each exercise, which means that your heart rate will stay elevated the whole time for an intense workout. This training style can help to improve muscular strength and endurance.
Kayla’s BBG program is based around plyometric circuit training and includes lots of jumping and bodyweight exercises.
Stands for ‘as many reps as possible’ where your aim is to repeat an exercise as many times as you can in a given timeframe. The goal of an effective AMRAP workout is to focus on intensity.
‘Every minute on the minute’ — as the name suggests, the workout is broken up into one-minute intervals. During each interval you will complete a specific number of reps of a certain exercise.
If you finish your reps before the minute ends, the remaining time is your rest. Once the minute is up, you repeat this process, start a new minute and work to complete the reps all over again.
What are the benefits of HIIT?
Are short workouts as effective as longer steady-state workouts? Here are some of the benefits of a HIIT workout.
Results continue after you complete the workout
High-intensity workouts burn more energy in a shorter period of time than steady state cardio, generating a bigger ‘Excess Post-Exercise Oxygen Consumption (EPOC), or ‘afterburn’ effect. This means that you continue to burn energy anywhere up to 48-72 hours after you finish the workout. Impressive, right?
A HIIT workout causes your body to be in an oxygen-deprived, or anaerobic, state. Anaerobic training can help to accelerate fat-burning when combined with a balanced diet. To build and maintain lean muscle using HIIT training, make sure that you include high protein foods throughout the day!
HIIT works to improve your VO2max, which is the maximum rate at which your heart, lungs and muscles can effectively use oxygen during exercise — it is considered one of the best indicators of cardiorespiratory fitness.
When you have an increased VO2max, your body can gain better endurance in aerobic exercises and may also improve overall health.
Decreases body fat
HIIT helps you to lose body fat while maintaining muscle. It does this by using the aerobic energy system to recover from intense repetitions of an exercise (the aerobic system uses carbohydrates and fat as the main fuel sources to supply energy to the body).
Build Type 2 fast-twitch muscle
Fast-twitch (Type 2) muscle fibres are used in explosive bursts of movements like those you find in HIIT. They make up your larger muscles like your biceps, quadriceps and calves and are important to maintain strength and a healthy metabolism.
HIIT challenges these muscle fibres, which require more energy to operate and grow and therefore can help you to burn fat more efficiently. Including HIIT in your workout program can increase your ratio of fast-twitch to slow-twitch muscle fibres, increasing your muscles power output and response time.
Regulates blood glucose levels
Recent studies suggest that HIIT can help to regulate your appetite hormones by increasing glucose metabolism and insulin sensitivity, helping to regulate blood glucose at healthy levels.
As a result, people suffering from pre-diabetes or type-2 diabetes may benefit from HIIT. To ensure this training style is suitable for you, always follow the advice from your health professional.
More efficient form of cardio
If you’re short on time, HIIT can help you to fit a workout into a busy schedule because it is more time efficient.
Who can do HIIT?
The great thing about HIIT is that anyone with a base level of fitness can do it. However, like with any form of exercise there is always a risk associated with it if you are new to the training style, or if you overtrain.
If you are a HIIT beginner, go at your own pace and listen to your body. If you have any prior injuries or health concerns, it is best to get cleared by a health professional before getting started.
Focus on your own capabilities, and not what others around you are able to do, modifying where necessary — you can start with lower-intensity exercises like those found in the beginner weeks of the SWEAT programs.
Examples of HIIT
Explosive bodyweight movements like tuck jumps, and jump squats are examples of high-intensity exercises that can work together to form an effective HIIT workout. If you are new to this training style, try this HIIT Workout for Beginners.
Where to complete HIIT
The great thing about HIIT is that it can be completed almost anywhere, with minimal equipment.
How to get the most out of HIIT
Here are some workout tips to help you to get the most out of each HIIT session, and recover effectively afterwards.
Allow recovery time
High-intensity workouts like HIIT or HIRT can create elevated levels of cortisol, which is the stress hormone in your body. It is important to allow your body to recover properly and adapt to this form of exercise.
You should aim to leave at least 48 hours between high-intensity workouts to allow your body to recover stronger.
Less is more
It’s important to keep your working intervals in a HIIT workout short. This will enable you to hit maximum intensity to get the full benefit of the workout with every interval.
In the earlier week of the SWEAT programs, HIIT cardio is optional and is introduced as you build your strength and fitness.
Use your rest breaks
You need rest breaks during a HIIT workout to allow your body to work at its full capacity during the high-intensity intervals.
During high-intensity work periods, your muscles get energy from the anaerobic system as oxygen can’t get to the muscle fast enough. During rest, your body reverts to anaerobic system, which requires oxygen. This is when fat can be used as a source of fuel.
Getting started with HIIT
When you start something as a beginner, like a new training style, you need to take steps to ensure your success. Here are some tips for getting started with HIIT.
Always do a warmup first
A good warmup before any workout is essential. A suitable warmup for HIIT may include low-intensity aerobic exercise like a slow jog, followed by some dynamic stretches to get your muscles warm and blood flowing.
Focus on your form
Before starting any high-intensity workout, make sure you are familiar with the exercises and confident with your form.
If you begin to fatigue during a HIIT workout, reduce the intensity of the exercise so that you are still able to complete each rep with proper form. This might mean using a lower weight, reducing the number of reps or switching to a less complex exercise.
A pre-workout snack might help
You use a lot of energy during HIIT, so it’s important that you eat before and after your workout. Staying hydrated throughout the day and having a pre-workout meal can help to prevent you feeling light-headed during the workout, and a post-workout snack can help you to recover faster.
Take the time to cool down
You should always end a tough HIIT session with a cool down, using stretching and foam rolling to focus on the muscles you have just trained.
RPE stands for ‘Rate of Perceived Exertion’, or how hard an exercise feels. It’s a scale of 1-10 that you can use to determine your effort during exercise. A score of 10 indicates a maximum effort. The work periods in a HIIT workout should be done at an RPE of 8.
Modify to suit your ability
If you are a beginner, a good place to start is with a 1:2 ratio. For example, do an exercise for a short period of time, say 30 seconds, then rest for one minute and repeat. As your fitness improves, transition onto a 1:1 ratio.
You can also start with lower impact high-intensity exercises. For example, instead of doing jump lunges you might start with reverse lunges, progressing to jump lunges as you get fitter and stronger.
Alternatives to HIIT
Exercising at high-intensity may not always be appropriate for your current health and fitness goals. However, there are plenty of other training styles that you can do to maintain and improve your fitness!
Strength training can help you to build lean muscle and reach your fitness goals, without the high-impact that HIIT can have.
Low-intensity cardio can also help to improve blood circulation, reduce fatigue and places less strain on your joints, ligaments and tendons than HIIT.
Ramp up your next workout with high-intensity interval training
HIIT workouts have so many benefits like increasing metabolism, improving cardiovascular health, and can help to promote faster results compared to steady state cardio. It can help you to get fitter, stronger and can help improve your overall health and wellbeing.
There are so many possibilities when it comes to HIIT, like running stairs or simply performing full body movements such as jumping jacks — any form of exercise that can get your heart rate right up!
Have you tried a HIIT workout yet? Let us know how you went in the comments below!
* Results may vary. Strict adherence to the nutrition and exercise guide are required for best results.