HIIT Workout: What It Is, Who It Suits and Sample Workouts

In short

Want a hard workout when you don't have much time? A HIIT workout alternates high-intensity effort with rest or easy movement, and you can do it with your own body weight. It has unique advantages, but it isn't suitable for everyone.

In this article, I will explain the benefits, the drawbacks, how to build a HIIT workout, and share excellent ready-made workout plans. So let's get started!

What is HIIT training?

HIIT is short for High Intensity Interval Training. It refers to a very specific kind of training. You can do interval training without doing real HIIT. HIIT is also not a specific activity, like running or lifting weights. It is about how you build the workout, as long as the intensity is high.

A session combines several rounds that switch between short periods of high-intensity movement and short breaks. The goal is to bring your heart rate to at least 80% of your maximum heart rate, then rest for a short time and go again.

You can do these workouts with your body weight, so they don't need special equipment. That is a great advantage, because you can do them anywhere you like. For ideas, see my guide to home workout exercises.

How hard is "high intensity"?

There are two simple ways to check that you are working hard enough.

By heart rate

• Estimate your maximum heart rate. The common formula is 220 minus your age. A large analysis of 351 studies, checked in a lab study of 514 healthy adults, found that 208 minus 0.7 times your age fits better, and that "220 minus age" underestimates the maximum in older adults. Both are only estimates; your real maximum can be quite different.
• Work out 80%. For a 40-year-old, both formulas give about 180 beats per minute, so 80% is about 144. For a 60-year-old, the newer formula gives about 166, so 80% is about 133.
• Use a chest strap or watch if you have one. In short intervals, heart rate lags and may peak only in the last rounds.

By effort (0-10 scale)

If you don't track heart rate, rate your effort from 0 (resting) to 10 (the hardest you can go):

Who is HIIT training suitable for?

HIIT suits people who already have aerobic fitness and want hard workouts that don't take a lot of time. If you have no aerobic fitness at all, build it first with simple cardio.

It is also excellent for athletes who want to improve their anaerobic threshold: the ability to keep working at a very high heart rate for longer before fatigue forces you to slow down.

I want to stress that these workouts demand a lot from your muscles, tendons, joints, ligaments, lungs, heart and whole body.

Stop right away if you feel chest pain or pressure, unusual shortness of breath, dizziness or faintness, a racing or irregular heartbeat, or sharp pain. If you have chest pain or pressure, or sudden severe trouble breathing, call your local emergency services immediately; do not wait to see whether it eases.

The benefits of HIIT training

HIIT can burn a lot of calories in a short time

A HIIT workout lets you do a lot of hard work and burn calories in a short time. I would not judge it by a promise that it burns the same calories as a longer run: the amount depends on the workout.

Your body keeps using energy afterward

After hard exercise your body keeps using extra oxygen for a while, to recover and restore its energy stores. This is called excess post-exercise oxygen consumption (EPOC), or the "afterburn". A review of the research found that this afterburn grows with harder and longer exercise and can last several hours after very demanding sessions. In the studies it reviewed, the afterburn was only about 6-15% of the energy cost of the exercise itself; the authors note that the share may be somewhat higher for interval sessions, which were harder to measure. In a randomized crossover study of 20 women, resting energy use during the first hour after a HIIT session was higher than after steady aerobic exercise or resistance training (study). So it is a real but small bonus: most of the energy is used during the workout, not after it.

It saves a lot of time

HIIT is ideal for people with a busy schedule, as long as they are fit enough. Because the workout is short, you can fit it in without investing a lot of time.

You can fit it in in the morning, before or after work, or after a weight-training workout. Basically, whenever you have a little free time.

Even with only four free minutes, you can fit in a work block using the Tabata method: 20 seconds of work followed by 10 seconds of rest, repeated 8 times. You can extend it to 20 rounds in total, but that takes longer than four minutes. I still include a warm-up and cool-down around the block.

What the research shows

• Fitness. A 2015 meta-analysis pooled 28 controlled trials with 723 healthy adults aged 18-45. Both steady endurance training and HIIT gave large gains in aerobic fitness (VO2max). HIIT gave a slightly larger gain, about 1.2 mL/kg/min on average.
• Body fat. A 2017 meta-analysis pooled 13 trials in adults aged 18-45 who were overweight or had obesity, training about 3 times a week for about 10 weeks. HIIT and moderate steady cardio both reduced fat mass and waist size modestly, with no difference between them, and HIIT took about 40% less training time. Body weight did not change much in either group, and in this analysis the cycling studies showed no fat loss. So HIIT is a time saver, not a faster route to fat loss.
• Where it fits. The WHO 2020 guidelines recommend that adults do at least 150-300 minutes of moderate-intensity aerobic activity, or at least 75-150 minutes of vigorous-intensity aerobic activity, or an equivalent mix, each week, plus muscle-strengthening activities at moderate or greater intensity that work all major muscle groups on 2 or more days a week. HIIT counts as vigorous activity, but a few short sessions a week don't add up to 75 minutes on their own, so combine it with other activity.

The drawbacks of HIIT training

Not suitable for beginners

HIIT is extremely intense, and you need good fitness to do it. If you are not used to training, it can put unnecessary stress on your heart and cause dizziness or vomiting.

If you are a beginner, start with simple aerobic workouts. Once you have built a good aerobic base, consider adding HIIT.

A higher risk of injury

In a HIIT plan you do the exercises fast and with little rest. That combination can badly hurt your technique.

My rule: if you cannot do an exercise with correct technique, stop. Chasing repetitions with poor technique will hurt you far more than it helps.

Not the most effective way to build muscle

If your main goal is bodybuilding and muscle growth, I recommend focusing on training plans built for hypertrophy (muscle growth). There are many such plans, such as an AB split or a full body workout (FBW). The research is clear that resistance training is the most effective training for building muscle; the 2026 ACSM position stand on resistance training reviews that evidence.

How to build a HIIT workout

To build a good, effective HIIT plan, you need to plan it carefully.

Before you start, I recommend a general warm-up for 5-10 minutes to prepare for the intensity of the workout.

The first step is choosing exercises. I recommend 4-6 intense exercises you can do for a short time and that work many muscle groups, such as push-ups, sprinting and burpees.

The second step is planning the rest times. My usual structure is 20-40 seconds of maximum effort, then 10-20 seconds of rest or light activity for recovery.

Of course, these work-to-rest ratios are not set in stone. You can vary them and build a session that matches your goals. You can do one set with short breaks and another with longer breaks. You can also add exercises with weights, and more.

After the workout, I recommend 5-10 minutes of light activity, such as walking and stretching.

Common work and rest structures

The shorter the rest, the lower the effort you can keep up in each interval. If your speed or reps drop a lot, lengthen the rest.

Examples of a HIIT workout plan

Here are four excellent HIIT workout plans for you. I recommend including the warm-up and cool-down described above with each one. They assume you already have an aerobic base.

Boxing HIIT (advanced)

Boxing is an excellent kind of training, because it builds speed, power, coordination and endurance. This session combines several boxing moves.

Do each exercise for 60 seconds at maximal intensity, then rest 30 seconds before the next one.

• Jab and cross: a straight punch with your right hand, then your left; if you are left-handed, reverse the order.
• Hook: a punch from the side, 30 seconds each side.
• Freestyle: any punches you like.
• Jump rope or burpees.

After all the exercises, walk for 60-90 seconds and start again from the top. Do this 3-6 times, depending on your fitness level. Keep your wrists straight, and don't lock your elbows hard at the end of a punch.

Anaerobic HIIT (advanced)

Complete the exercises 4 times, resting about 15 seconds between exercises.

• Pull-ups: as many reps as you can in 30 seconds.
• Jumping jacks: 30 seconds.
• Burpees: 30 seconds.

Do controlled pull-ups and stop the set when your form breaks. If you cannot do several clean pull-ups yet, use a band, an assisted machine or inverted rows.

Lower-body HIIT (advanced)

Complete the exercises 4 times, resting 15 seconds after each exercise.

• Sprint: 30 seconds.
• Lunges: 20 on each leg, with body weight.
• Jump squats (as high as you can): as many as you can in 30 seconds.

Land softly on jump squats, with your knees in line with your toes. If your landings get loud or sloppy, switch to regular fast squats.

Ab HIIT (intermediate)

Do each exercise for 40 seconds, then rest 10-15 seconds before you move to the next one.

• Bicycle crunches
• Lying leg raises
• Plank

For more options, see my guide to the best ab exercises.

HIIT vs classic interval training

You can do interval training without doing a real HIIT workout. The exercises can be the same; the intensity and the way you arrange work and rest are what matter.

My HIIT examples focus on short periods of maximum effort, followed by relatively short rest. You do several exercises with minimal rest between them, then rest a little at the end of the round and start again.

For a less intense interval workout, you can run for 2-3 minutes, then walk for 2 minutes. The walking break lets you recover between efforts and build a longer workout.

You can adapt interval training to a wide range of goals. HIIT is an excellent choice when you want a short workout with very high intensity. Short rests are part of my examples, rather than a rule for every HIIT workout.

Safety

Build an aerobic base first, warm up for 5–10 minutes, and rehearse your chosen movements at an easy pace with light weights before the hard intervals. If you use a bike, adjust the seat and secure your feet; if you use a barbell, secure the plates with collars and use safety arms or a spotter where needed.

Keep each repetition controlled, land softly on jumps, and end the interval if you feel pain or dizziness or your form breaks down, even if the timer is still running. If your speed or repetitions drop sharply, extend the recovery break instead of forcing the next interval.

Leave an easy or rest day between hard HIIT sessions, and choose shorter intervals, lighter weights or fewer rounds when you have not recovered from the previous workout. Progress one thing at a time—rounds, work duration or intensity—and only when you can finish the current session with controlled technique.

Bottom line

HIIT is an outstanding option when you don't have a lot of time to train. It is a good choice for endurance, strength and burning calories, while resistance training remains my priority for building muscle. If you are thinking of starting, you need a basic level of aerobic fitness first.

Build that aerobic base, choose exercises you can perform well, and use work and rest times that match your fitness. Then pick one of the examples and get started!

Frequently asked questions

How long should a HIIT workout be?

That depends on the plan and how many rounds you choose. Six rounds of the boxing example contain 24 minutes of exercise alone; the rests and walking breaks take it beyond 30 minutes, before the warm-up and cool-down. Include those when planning your time.

Is HIIT better than steady cardio for fat loss?

Not clearly. In a meta-analysis of adults with overweight or obesity, both reduced body fat similarly; HIIT simply took less time.

Does HIIT burn fat for hours after the workout?

Not much. The extra energy your body uses after hard exercise is small compared with the workout itself.

Can I do HIIT at home without equipment?

Yes. Bodyweight moves such as fast marching, squats, lunges, push-ups and burpees work well. Choose low-impact moves if you have neighbors below or sensitive joints.

What is the difference between HIIT and Tabata?

Tabata is one type of HIIT: 20 seconds of work and 10 seconds of rest, classically for 8 rounds.