HIIT: 10 Reasons Why You Should Add it to Your Routine
Struggling to fit cardio workouts into your busy schedule? High-intensity interval training (HIIT) might be the perfect solution.
HIIT delivers maximum results in minimal time, helping improve your fitness, boost endurance, and keep your training routine varied.
Keen to get started? Let’s dive in.
What is HIIT?
HIIT is a category of training that centres around short blasts of intense exercise followed by a brief recovery period. So, you might do 30 seconds of all-out movement, followed by 30 seconds of recovery, and then repeat this for the desired time.
But what makes it unique is the focus on heart rate (HR), which should be between 75 - 95% of your maximum during the working sets.
Calculating your maximum heart rate (MHR) is simple: just subtract your age from 220. So:
If you’re 20, your MHR is 200. The 75 - 95% working range would be 150 - 190 beats per minute (BPM).
If you’re 40, your MHR is 180, which means your heart rate should be between 135 - 171 BPM.
Because these workouts are so high-intensity, you can achieve a lot in a short period of time – around 15 - 30 minutes is all you need.
What’s the difference between HIIT and circuit training?
We know what you’re thinking: “But that sounds just like circuit training!”.
And you’d be right to a certain degree; there are a lot of similarities between HIIT workouts and circuits.
However, there are a couple of crucial differences. The first, as we’ve just looked at, is the focus on heart rate zones and the need to be close to your MHR in a HIIT workout. Those numbers determine whether a workout is truly “HIIT” or not; circuit training usually works at a lower intensity within more moderate HR zones.
And where circuits often involve equipment such as kettlebells, dumbbells, or even barbells to target strength, endurance, and cardio, HIIT focuses purely on the latter. Any strength-based work is typically done as a bodyweight exercise (for instance press-ups, or sit-ups), with the emphasis being on speed and constant intensity to stay within those HR parameters.
Types of HIIT
Far from just being a “one size fits all” approach to training, HIIT is really adaptable: you can modify it according to your training background, your fitness level, whether you have any injuries you need to work around, how much time you have to work out, and simply what you enjoy doing.
There are multiple ways to measure both the time and rep elements of HIIT, including:
One-to-one
The most basic form of HIIT training involves working out for the same amount of time you rest. For example, 30 seconds on, 30 seconds off, or 1 minute on, 1 minute off. You can make this more challenging as you get fitter by adjusting the working and resting times.
Tabata
This style of HIIT involves 20 seconds of work followed by 10 seconds of rest, repeated 8 times. You can do Tabata-style intervals with any form of movement: running, cycling, swimming, or bodyweight exercises.
Every minute on the minute
Known more commonly as “EMOM”, this involves completing a set number of reps at the start of a minute and then resting for the remainder. So, for example, if you set yourself a target of 10 press-ups and completed them in 20 seconds, you’d rest for 40 seconds before going again.
EMOM is perfect for rep-based bodyweight movements; think lunges, core exercises, and even burpees (if you dare!).
As many rounds as possible
“AMRAP” workouts involve completing as many rounds of a set list of exercises in a certain amount of time. So, you could do 10 bodyweight squats, 10 press-ups, and 10 sit-ups and see how many times you could get through that routine in 3 minutes.
To make this class as HIIT, you’d have to have a short break then and then do either the same routine again, or a different set of exercises so that you were completing intervals between working and resting.
What are the benefits of HIIT?
Now that you know all the various ways you can adapt HIIT, let’s look at why high-intensity intervals are such a brilliant workout option.
Aside from the fact you can be done and dusted in less than half an hour, there are numerous other benefits to high-intensity interval training. Here are just 10 reasons why you should add it to your routine (but there are plenty more!).
1) Improve your cardiovascular health
HIIT workouts are great for your heart and circulation. They help improve the function of the cells that line your blood vessels, making your arteries more flexible. This allows blood to flow more easily, reducing strain on your heart, making your heart stronger, and supporting overall cardiovascular health.
2) Improve your anaerobic and aerobic fitness
Let’s take a quick look at the differences between your “anaerobic” and “aerobic” systems:
The aerobic system supplies your organs, muscles, and cells with long-term energy through the breakdown of oxygen. It enables you to exercise for long periods of time: think steady runs, bike rides, or swims that last upwards of 45 minutes.
The anaerobic system breaks down glucose for energy without using oxygen, and has two parts: the first is the ‘alactic anaerobic system’, which provides energy in short bursts of up to 10 seconds (for instance, when you’re weightlifting, or running a very short sprint). The second is the ‘lactic anaerobic system’, which kicks in after about 10 seconds and will fuel you for 90 seconds of high-intensity movement. You’d use this system for a 400m sprint, a 90-second max effort on a bike, or a fast 50m swim.
HIIT uses and strengthens both: intervals improve your aerobic capacity by putting your cardiovascular system through repeated bouts of high-intensity exercise, and enhance your anaerobic capacity by forcing your muscles to work at maximal effort, improving their ability to generate energy without oxygen.
3) Improve your VO2 max
Linked to your aerobic fitness is your VO2 max, which refers to the maximum amount of oxygen your body can absorb and use during exercise.
Studies show that high-intensity intervals improve VO2 max more than moderate training; and, in general, the higher your VO2, the better your aerobic fitness will be.
4) Develop muscular strength and endurance
While HIIT sessions don’t focus on strength, including bodyweight exercises like squats, lunges, tricep dips, and press-ups in your interval workouts can contribute towards hypertrophy when paired with resistance training. In fact, it’s been proven that press-ups can be just as effective as bench pressing when it comes to developing muscle.
Plus, doing these exercises in an interval format over the course of 15 - 30 minutes can also help increase your muscle’s ability to work at their maximum capacity over a longer period.
The key to ensuring your interval training still has some muscle-building benefit is completing the exercises with good form, taking your body through a full range of motion. You’ll benefit more from doing 15 excellent press-ups in 30 seconds, than 25 really bad ones!
5) Reduce your blood pressure
There is a growing body of evidence to suggest that HIIT is more effective than continuous moderate-intensity exercise when it comes to lowering blood pressure.
Scientists have found that intense interval workouts can both lessen the likelihood of developing high blood pressure (also known as ‘hypertension’), and reduce blood pressure levels in those already suffering from the condition.
6) Boost your sleep
We all know how much easier it can be to nod off if you’ve completed a big workout during the day.
And interval training is no exception – it’s been proven that HIIT workouts improve both sleep quality and sleep efficiency.
Studies have found that people who do regular HIIT sessions tend to fall asleep faster, wake up less during the night, and feel more rested in the morning.
7) You don’t need any equipment
HIIT is a really accessible form of training because you don’t need any equipment.
You can hit the roads and do an interval run, or combine whole-body exercises to create a highly effective workout that you can do at home.
All you’d need for either of these options would be some comfortable training shoes and your favourite workout gear (our range of men’s training clothes and women’s training clothes includes tops, tees, shorts, leggings and accessories). And maybe a mat for your bodyweight exercises, but that’s not essential.
8) You can do it anywhere (even at home)
Interval training is a really versatile and adaptable way to work out, wherever you might be.
And because you don’t need any equipment, you can do HIIT workouts literally anywhere: at home (either inside or in your garden if you have one), on the beach, in the park, out on the road during a run, or in the pool while doing a swim.
9) It adds variety to your training
You can create endless variations of HIIT workouts using cardio, bodyweight exercises, and timing systems like EMOM.
Try adding intervals to your next run, bike or swim to create a fun cardio HIIT workout, or set yourself the target of doing different bodyweight arm, leg, and core exercises every time you do intervals.
You’ll never get bored because you can do something slightly different every time you train; plus, mixing up your movements reduces the risk of repetitive strain injuries.
10) It’s an enjoyable form of exercise
You don’t need to exercise in a way you don’t enjoy; movement should be something you look forward to.
So, if sitting and turning your legs over on a bike, or going for a steady-paced run doesn’t sound like your idea of fun, give interval training a go: evidence shows that high-intensity interval exercise can be more enjoyable than moderate-intensity continuous training.
Fun, challenging, and highly beneficial: HIIT really is a win-win workout option.
Example HIIT workouts
The beauty of HIIT lies in its customisability – but having so much choice can be overwhelming.
So if you’re looking for inspiration for these fast-paced training routines, then we’ve got you covered. From high-intensity interval cardio to home-based HIIT workouts, you can adapt all of these suggestions to suit your fitness levels.
HIIT cardio workouts
You can perform these workouts running on the roads or on a treadmill, cycling through the countryside or on a static bike in the gym, or even swimming in the pool.
Start using the one-to-one method by working for 1 minute, then resting for 1. Aim to repeat this for 8 - 10 sets. If this is a little too tricky for the moment, add another 30 seconds to each rest period.
Then, once you can do that comfortably, try working out for 90 seconds, then resting for 1 minute, and repeating for 8 - 10 sets.
You can keep altering the working and resting time to make the workout suit your abilities – just remember to keep an eye on your heart rate to ensure it’s between 75 - 95% of your maximum. If it’s in this zone, you’re in the sweet spot no matter how fast you run, cycle, or swim.
If you don’t have a stopwatch to hand, you can also do a HIIT cardio session using distances. Try swimming (or water jogging) one length of a pool as fast as possible, then gently swimming or walking one length.
And if you’re on a running track, run or jog for one lap, then walk briskly for one. When that starts to feel easy and isn’t elevating your HR as much, try walking the straights and running the bends. Or if you’re out on the road, run at your max effort for the distance between five lampposts, then walk for three.
As you can see, when it comes to high-intensity cardio, the possibilities really are endless; you can tailor these workouts to look however you want. So long as your HR is high enough, then you’ll reap the rewards.
But just remember that if you want to go all-out with your intervals on the road, you’ll need to protect your feet and joints. Our men’s training shoes and women’s training shoes are designed for ultra comfort and all feature enhanced cushioning and innovative materials to lessen the impact of hard running on your body.
Home HIIT workouts
Grab a bottle of water and move your coffee table: you can do this whole-body, 20-minute workout from the comfort of your living room.
Make sure you’re sufficiently warmed up: a minute of jogging on the spot followed by another minute or two of dynamic stretching will be fine. Then, complete all five exercises in order. Work for 30 seconds, then rest for 30 (or do 40 seconds work with 20 seconds rest if you want more of a challenge):
Bodyweight squats or jump squats
Mountain climbers
Burpees
High knees
Plank
Rest for 1 minute, and repeat for a total of 4 rounds.
This next option alternates between cardio, arms, legs, and core, giving each body part a rest while you work on another, and with a few minutes of warm-up and cool-down, this should take you no more than 30 minutes.
Complete all 8 exercises, then rest for 1 minute before starting the next round. Repeat for 3 rounds. Off you go!:
Star jumps
Press-ups
Bodyweight squats
Bicycle crunches
High knees
Tricep dips
Lunges (alternating legs)
Plank shoulder tap
And if out-and-out cardio is your focus, then give this full-body HIIT session a go. But be warned: it’s tough! Complete all 6 exercises, in order, with 30 seconds work followed by 30 seconds rest (or 40 seconds work with 20 seconds rest if you really want to test yourself), then rest for 1 minute. Repeat for 3 rounds:
Star Jumps
High Knees
Burpees
Mountain Climbers
Jump Squats
Skaters
Don’t forget that you can also do these sessions in an EMOM format: pick any of the above routines and complete 10 of each exercise, rest for the remainder of the minute, and then progress on to the next movement. Repeat for as many rounds as you like, but ideally, a minimum of 3.
Or, if you’d rather complete a workout where no exercise is repeated, pick 15 - 20 different bodyweight exercises and just do each movement once, for either 30 seconds on 30 seconds off, or 40 seconds on 20 seconds off for a swift yet effective workout.
Gym HIIT workouts
If you’re working out in the gym, then there’s almost no limit to the amount of different interval workouts you can try, either by sticking on one piece of cardio equipment or throwing some bodyweight exercises into the mix.
All of the above circuits can be adapted to a gym environment by adding in working sets on a static bike, treadmill, rowing machine, stepper, or any other cardio equipment – but try to plot your series so that you can easily get from one piece of kit to the next in the allotted rest time.
The ideal way to incorporate both cardio and bodyweight strength exercises is to pick your favourite piece of cardio equipment, grab yourself a mat and place it as close as safely possible. Then, try the following. Complete all 10 exercises in order (30 seconds on, 30 seconds off) and repeat the full routine twice:
Cardio
Jump squats
Press-ups
Cardio
Burpees
Plank
Cardio
Alternate lunges
Crunches
Cardio
High-intensity training: big impact, small time commitment
Whether you’re short on time, looking to improve your fitness, or just want to add variety to your workouts, HIIT is an incredibly effective and accessible way to train.
With so many ways to structure your sessions at home, in the gym, or outdoors you can easily find a style that suits your goals and keeps things fun while making you fitter, healthier and stronger.
