Want to get more out of your cardio routine?? Look no further than high-intensity interval training, an incredibly popular workout trend that lives up to the hype. Unlike traditional cardio, in which you maintain a steady heart rate for the duration of the workout, HIIT alternates between periods of high intensity and low intensity.

The Principles of HIIT

In order to reap the full benefits of HIIT, you have to first understand the principles. HIIT involves short periods of work followed by rest periods. The time for recovery allows you to regain energy so you can push yourself to the max during the work periods. Think about it — you wouldn’t be able to sprint your hardest for twenty minutes straight. But if you do a 30 minute HIIT sprint workout, in total you’ll have sprinted your hardest for fifteen or twenty minutes (balanced by rest periods).

Push Your Limits

By the end of an interval, it should feel like you can’t do another rep. But don’t worry, you have a rest period during which you can recover (slightly). The intensity can seem intimidating, but it’s what makes HIIT so effective for burning fat and building lean muscle. If you have a FitBit or Apple Watch, these can help you determine exactly how hard you’re pushing yourself. Aim to get to 80 to 95% of your estimated maximum heart rate. Or, you can refer to the Rated Perceived Exhaustion Scale (RPE). The RPE ranges from 0 (nothing at all) to 10 (very, very heavy), and you should be at about a 9 during the work periods of a HIIT workout.

Rest Periods are Essential

The work to recovery ratio is the other key to a successful HIIT workout. Because of how hard you’re working your muscles and cardiovascular system, rest intervals are necessary to keep you going throughout the entire session. The ratio of intensity to recovery varies, as does the duration of the whole workout.

Start Small

HIIT workouts can last anywhere from five minutes to thirty minutes, so don’t feel obligated to go all out during your first session. In fact, make sure you start small, so to speak, to avoid any injury that might occur if you challenge yourself too much at first.

This is essential to keep in mind if you’re a sedentary person and don’t exercise very much. However, if you regularly do cardio, the transition to HIIT should be more straightforward.

Don’t know where to start? There are so many different iterations of beginner’s HIIT workouts available at your fingertips online. You can also check out this post on the different types of core exercises.

Here’s an example of a strength training focused HIIT workout that you can try:

10 Minute HIIT Workout

Do each exercise at high intensity for 45 seconds, followed by 15 seconds of rest.

• Mountain climbers
• Push-ups
• Squats
• Crunches
• Burpees
• Plank
• Jump squats
• Tricep dips
• High knees
• Lunges

How to Progress

Starting out, your HIIT workouts might last five or ten minutes. Eventually, you can work your way up to thirty-minute workouts, but don’t make them any longer than that. If you feel like you can keep going after a thirty-minute long HIIT workout, you’re probably ready to work even harder. The beauty of HIIT, and one of the reasons it’s so popular, is that it doesn’t take very long. You can lose as many calories in a HIIT workout as you would doing steady-state cardio, in only half the time. A word of caution: extending a HIIT workout longer than you should result in overworked muscles, and possible injury. Take it slow, and add on as you progress through workouts!

Progressing Through HIIT Workouts

So, how can you continue to make progress if you’ve tackled a thirty-minute long HIIT workout?

Amp up your work to rest ratio

If you feel like you’ve hit a plateau in your HIIT journey, play around with your work to rest ratio — that is, increase the work time and decrease the amount of rest time. Or, you can make your “rest” time more active. For example, if your routine includes burpees, do a plank during the rest period.

HIIT it more

You can also increase the number of times a week you’re doing interval training. If you start out doing HIIT once a week, you can work your way up to three, four, or even five times a week. Just make sure you’re allowing yourself enough time to recover between sessions. With HIIT, you can feel good about rest days. Another bonus of this popular form of exercise is that you continue to burn calories for about 24 hours after a HIIT workout, due to a phenomenon called excess post-exercise oxygen consumption (EPOC).

Switch up your routine

Although it’s important to consistently work on the same muscle groups weekly to see muscle growth, try out new HIIT routines regularly, or add more challenging variations to the ones you’re already doing. This will help you grow stronger and keep your workout routine more exciting. You may find that you enjoy some routines better than others. The more you try, the more you’ll be able to design a routine that works best for you.

No matter the fitness level you are at today, anyone can start doing HIIT workouts. They’re easily adaptable — you can switch up your work to rest ratio, change up your routine, and more — so you can make real, visible progress over time. What’s more, numerous studies have shown that people enjoy HIIT more than steady-state cardio. So if nothing else, you can enjoy HIIT workouts for the pure pleasure of doing them alone! This exciting, fast-paced exercise trend is here to stay, and we can’t wait for you to try it.