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How Long Should A HIIT Workout Last To Maximize Fat Loss?

By Nick Holt / July 1, 2017

By now you’ve most likely heard about HIIT, or High Intensity Interval Training. And for a good reason. It’s a highly effective way to burn fat in a very short amount of time. For example, one of the most popular HIIT methods called Tabata training lasts for only 4 minutes!1

But before you drop all of your other training in favor of 4-minute workouts, let’s talk about the following key concepts:

  • What is HIIT?
  • How long should an ideal HIIT workout last?
  • How much HIIT is too much?
  • Potential downsides of HIIT
  • Sample HIIT Workout
  • What is HIIT?

    Without getting too complicated, HIIT simply means that you alternate between a high intensity exercise for a given time and a lower intensity exercise (or rest) for a given time. A great example of a HIIT workout is sprinting at near-maximum speed for 30 seconds, followed by walking for 30 seconds.

    HIIT workouts usually prescribe specific work and rest periods, as well as a given number of rounds to complete. In the above example, 30 seconds on and 30 seconds off equates to a 1:1 work-to-rest ratio. And for an intense workout, you could perform a total of 10 sets of sprints.

    Japanese researcher Izumi Tabata popularized the “20 seconds work to 10 seconds rest” interval. And it’s his research that kick-started the whole movement towards HIIT training as a viable alternative to the typical steady state cardio approach.

    What Research Says About HIIT Workouts

    In a study on Olympic speed skaters, Tabata found that a certain type of HIIT training – 8 rounds of maximum intensity 20-second intervals (at 170% of VO2 max) followed by 10-seconds of complete rest – was more effective at increasing the conditioning of his athletes than normal steady state cardio (at 70% of V02 max). This study was performed using stationary bikes.

    Since then, there have been a number of other studies supporting the idea that HIIT is more effective at burning fat than typical steady state cardio (like biking or jogging).2 For example, one study measured the effects of 15-weeks of HIIT versus steady state exercise on young women. While the women in both groups improved their conditioning, only the women in the HIIT group experienced improvements in their weight, body composition, and fasting insulin levels. 3

    Why Is HIIT More Effective At Burning Fat?

    The objective with HIIT workouts is to crank your heart rate up to 85-90% of its maximum so that you are working “anaerobically”, or without oxygen. This leads to EPOC (Excess Post-Exercise Oxygen Consumption), also known as the afterburn effect, where you’re burning more calories throughout the day because your body has to recover from that intense exercise.

    When you’re jogging at a moderate pace, you’re using a different energy system (aerobic), which primarily uses oxygen to fuel your muscles. In other words, when you go for a casual jog, you don’t induce the afterburn effect and therefore don’t burn any additional calories later in the day.

    An important note to keep in mind – all of the studies on HIIT’s effectiveness have shown that you really need to be close to your maximum heart rate to reap the benefits of HIIT. What this means is, the most effective HIIT workouts are going to be freakin’ HARD.

    How Long Should a HIIT Workout Last?

    This seems to be the million-dollar question these days. According to a popular NY Times article, there is research that supports the idea that all you need is 7 minutes.

    On the other end of the spectrum, I’ve had clients tell me they go to hour-long HIIT classes at the gym. To say there is huge variance is an understatement.

    Determining the perfect duration of a HIIT workout requires a bit of experimenting.

    I’ve found that the sweet spot is somewhere in the 20-30 minute range. If your workout lasts any more than 30-minutes, you’re probably not working hard enough to optimize the benefits of HIIT. Any less than 15 minutes, and you probably haven’t spent enough time at that high exertion level to make a meaningful difference.

    Don’t get me wrong, 5 minutes of any exercise is better than sitting on the couch. But if the question is, what is the optimal duration for a HIIT workout to be the most effective, I would say 20-30 minutes.

    There are plenty of other factors that determine what is best for YOU and your lifestyle, but I think that is a good range to shoot for.

    Possible Downside of HIIT Workouts

    1. Too Much Stress

    One potential downside of HIIT workouts is that they are very metabolically demanding and induce a decent amount of stress on the body. The thing with stress is that a little bit is good – stress is what makes us stronger and more fit, but too much stress on the body has potential to cause problems.

    Our bodies don’t differentiate between exercise stress and life stress. If you live a modern lifestyle, you most likely have a lot of other stressors contributing to your total stress levels. Maybe you sit in traffic most days of the week or have challenging relationships at work, or your family and social demands cut into good sleeping patterns. All of these factors influence the ideal frequency and duration of your HIIT workouts.

    My point is that – if you live a busy and stressful life, adding a bunch of 60-minute HIIT workouts every week might be too much.

    Assuming you sleep pretty well and have some kind of stress management system in place (yoga or breathing exercises work really well here), I would say that incorporating 3 days of 20-30 minute HIIT workouts each week is a great target to aim for. Add one heavier lifting session incorporating long rest between sets to ensure you’re building muscle, and you have a really solid workout program to get lean and stay fit.

    Of course, everything depends on your activity level and specific goals.

    2. Not For Muscle-Building

    The other possible downside of HIIT is that, if your goal is to pack on muscle and get really strong, HIIT just doesn’t produce the goods. Interval training is great for fat loss and maintaining muscle mass, but for people who want to get bigger and stronger, lifting heavy weights with good form should be prioritized over HIIT.

    So, if you’re looking to get leaner and stay fit, HIIT is a great option.

    My Favorite HIIT Workouts

    1. 30:45 Sprints

    This is an intermediate to advanced HIIT workout. Perform 5-10 minutes of a dynamic warm-up before starting. You’re going to perform 30 seconds of work followed by 45 seconds of rest.

    Instructions: Complete 15 rounds of the following:

  • Sprint for 30 seconds at near-maximum effort.
  • Walk for 45 seconds.
  • 2. 30:60 Kettlebell Swings

    Start with 5-10 minutes of a dynamic warm-up. You’re going to perform 30 seconds of work followed by 60 seconds of rest.

    Instructions: Complete 10 rounds of the following:

  • Kettlebell swing for 30 seconds at near-maximum effort.
  • Invisible jump rope for 60 seconds.
  • If you have a favorite HIIT that you do, I want to hear about it. Drop me a message in the comments below!


    • Pamela says:

      Why you can't alternate body-building with HIIT?

    • chopstix says:

      question...what of a 50 plus yr old guy getting back into fitness after a 6 mo hiatus...is it best to get general conditioning (4x/week weights and moderate aerobics each section is 30-45 min/day) and then when you have a base in the 2nd month to introduce ihit? and then how often ...2x/week?...i have a signif leg lenth diff, scoliosis and stenosis so running isn't comfortable on the right side (longer leg side)...would love more links for 50plus people too...there is a growing host of us who want to remain in great shape into our later yrs.

    • Tam says:

      Just what I needed to read...I am what you call skinny fat...been doing cardio + restricting calories for the last 6 weeks but have had next to no change in my body composition. Last week I began HIIT 20mins 3x per week and strength training twice per week and I tell you what, this is the first week where I am feeling it work thanks for the great article.

      • Kristin Rooke, CPT says:

        Hi Tam,

        So glad to hear you're experiencing the physique changes you want! Yes, HIIT and strength training are incredibly effective at building a lean and strong body. Keep up the good work!

        -Kristin, BuiltLean Coach & Managing Editor

    • Mushtaq Alzuhairi says:

      I go up and down the stairs for 30 sec and rest for 30 sec. I usually do 10 min of it post workout but according to this article this is not enough so ill try to push it up to 20.

    • Eve says:

      I love HIIT. Find it to be the most challenging fat burning activity. As a person who loves running but also like lifting weights to get cut up it can be hard to keep a balance of enough muscles verses losing extra fat. I use 1:00 high intensity to :30 seconds rest mostly but have tried other interval times as well. Here are a set of workouts I do that for me are pretty hard and kick my ass.
      2 Jumping jacks proceeding 2 high jumps
      Bear crawls
      Jumping lunges
      Lizard push-ups
      Burpees with jumps
      Jumping squats
      Mountain climbers
      Those are some of the workouts I use hiit!

      • Kristin says:

        That sounds like a great workout! Good exercise selection, and definitely tough with 1 minute of work and only 30 seconds of rest. I'm not surprised that workout kicked our butt - it'd kick mine too! Keep up the great work.

        -Kristin, BuiltLean Coach & Managing Editor

    • Hannah says:

      One of the best HIIT workouts I ever did was in preparation for rugby. We had an indoor 200M track so I would start about halfway across the short side (just where there was a little workout area) jog the long side, accelerate the short side, sprint the long side. Slow down coming into the area, then do 10 pushups. I would keep doing this as a ladder for the pushups so it was 10,8,6,4,2,2,4,6,8,10. Absolutely dead by the end of it, with the combination of jogging sprinting and strength. It also ended up being about a mile of sprinting and 60 pushups. Really got me in shape for both jogging and being able to immediately sprint then use force, for anyone that knows stuff about rugby it's pretty much jog, sprint, hit for 80 minutes.

      • Kristin says:

        That sounds like an awesome workout, Hannah! I'm definitely going to add that to my workout routine. I've been looking for an effective and fun sprint workout, and this one sounds perfect. Thanks!
        -Kristin, BuiltLean Coach & Managing Editor

    • Metka says:

      I have been doing hiit with 5 exercises in the workout. Usually I was doing an exercise around 8 times (20/10) and than moved to another exercise. By that I was really tired when the exercise was finished. I wonder if I would get the same result if I did every exercise once and that repeated that 8 times (still 20 min total)? I tried that once, but at the end I wasnt that tired as usually. Is it the same if I just want to lose fat? What about if I want to gain muscle?

      • Nick Holt says:

        Hey Metka! Good question. Really depends on what exercise you are doing. You want to really push the intensity on the work period and if you do 2 exercises that work the same body part, you wont be able to push as hard. That make sense?

        I like to do an upper body exercise (let's say a push-up or row) and combine it with a lower body exercise (say a squat or KB swing) and alternate between those 2 moves for the duration of the HIIT. I would say that's the best for fat loss.
        If you're looking to gain muscle, I would switch out a HIIT workout and do more of typical strength training set where you are doing heavier weights, set reps somewhere in the 8-12 range, and resting longer between sets. Of course nutrition on both the fat loss goal (slight calorie deficit) and the muscle gain goal (calorie surplus) would have to be on point as well.
        Hope that helps!!

    • Barney Foley says:

      Hello! I'm just starting to review your material and it looks fantastic!
      I've just started this program based on your articles and am on the waiting list to actually start the program.
      My question is about HIIT.
      I have a back issue that prohibits my doing sprints, bicycling, and most aerobic workouts. I am able to use a recumbent stationary bike and will be doing the HIIT workouts on that.
      My question/s is/are:
      - How many times per week should I be doing the HIIT workouts?
      - I was thinking of doing HIIT on MWF and then a stretching workout I use (Tai Cheng) on Tue/Thu/Sat. Is that OK?
      - I thought I'd do them in the mornings and then a weight training workout at lunch. Is that advised?



      • Tim C. says:

        Hi Barney. I read your comment and wanted to express how great your workouts will be on the Builtlean program and my experience with it. I am currently on week 5 of the program and am loving every minute of it. I am sure you will too.
        As far as the HIIT question, their workouts get your heart rate plenty high, especially the finishers at the end of the workout.
        Also their workouts are very effective at targeting many muscle groups. I notice that various movements I do on a daily basis at work are becoming easier. My body overall is moving better and I am increasing strength.
        The warmups as well as cool downs they do also include stretching. No doubt with your experience in a stretching regimen already that part will be a breeze for you. Have fun with their program. Take care.

        • Kristin says:

          Thanks for sharing your experiences with BuiltLean Transformation, Tim! It's awesome that you're finding that daily life activities have gotten easier. Keep up the great work, and Happy New Year!
          -Kristin, BuiltLean Coach & Managing Editor

      • Kristin says:

        That sounds like a great approach, Barney. You can absolutely do HIIT on a recumbent bike. In terms of how often you should do HIIT, I would recommend starting with 1-2 HIIT workouts per week for the first 2-3 weeks to allow your body to adapt to more intense workouts. Listen to your body, and if you feel like your body is ready for more, add another day of HIIT.

        Alternating between HIIT workouts and stretching is a great way to keep your body limber and injury-free while doing more intense training. And you can definitely do HIIT in the morning, and a strength workout later in the day. Pay attention to how you feel during your strength workouts though - HIIT is intense and can take a lot of energy out of you. If you notice that you're not as strong during your strength workouts after doing morning HIIT, consider doing strength and HIIT on alternate days.

        Does that all make sense? Let me know if you have more questions.

        -Kristin, BuiltLean Coach & Managing Editor

    • Ankur Singh says:

      My HIIT is as follows :
      1A : Barbell Deadlift (12reps, 3 sets, 45 secs between sets)
      1B : Dumbbell Bench Press (12reps,3sets, 45 secs between sets)
      2A : Dumbbell Reverse Lunges (12reps, 3 sets, 45secs bw sets)
      2B : Barbell Shoulder Military Press (12reps, 3sets, 45secs bw sets)
      3A : Goblet Squat ( 12reps, 3sets, 60secs bw sets)
      3B : Kettlebell Swing ( 12reps, 3sets, 30secs bw sets)
      4A : Decline Dumbbell Fly (12reps, 3 sets, 45secs rest)
      4B : Decline Dumbbell Pullover (12reps, 3sets, 45secs rest )
      It takes around 45 - 50 mins. At the end of workout i am sweated and feel a bit exhausted (eyes feeling closing down, body demanding water) and i dont take any meal for next 1 hour.
      I am feeling that i should decrease rest time between sets in 1A,1B,2B,3B,4A,4B to 20 secs and 30 secs for 2A. However Squats really make me feel like vomiting if i try to increase the reps or decrease the rest time.
      Your suggestions are most welcome, but these are the only exercises i want to do in my HIIT, cant go for running cycling etc etc.
      No stress in my lifestyle, Healthy eating proper sleeping is there.
      Main aim : Shredding fat at first, once thats done, building a medium toned physique

      • Marc Perry, CSCS, CPT says:

        Hi Ankur, if you want to lose body fat, it's mostly a nutritional challenge. I recommend creating more precision with your nutrition regimen. If you decrease rest between exercises, that will help make the session more effective, but you also don't want to make yourself feel like you are going to throw up. Consider moving the KV swings until the end of the workout as they are a challenging exercise to combine with squats.

    • Ankur Singh says:

      Thanks for response Marc, as per the body adaptations i have modified the workout session as :
      1A Barbell Deadlift (3 sets, 12reps, 10 secs rest)
      1B Dumbbell Bench Press (3 sets, 12reps, 15secs rest)
      2A Dumbbell Reverse Lunge ( 3sets, 12 reps, 15secs rest)
      2B Barbell Military Press ( 3sets, 12reps, 15secs rest )
      3A Goblet Squat ( 3sets, 12 reps, 45secs rest)
      3B Dumbbell Single Arm Row( 3 sets, 12 reps, 15secs rest)
      4A Barbell Good Morning (3sets,12reps, 15 secs rest)
      4B KV Swing( 3 sets, 12reps, 10secs rest)
      5A Dumbbell Row Incline Prone (3sets, 12 reps, 20secs rest)
      5B Incline Dumbbell Fly (3 sets, 12reps, 20 secs rest)
      Between two supersets a rest of 60 secs.
      Enough of sweating and pumped up heartbeat.
      I am comfortable as well as pushing myself in this workout form, and nutrition is wholly balanced with minimum amounts of fat and carbs and maximum amount of green leafy and protein rich food, milk etc.