By Dr. Mercola
Virtually everyone who exercises wants to get the most benefits in the least amount of time.
Not all exercises are created equal in this regard, and it's become quite clear that focusing on slow endurance-type exercises, such as running on a treadmill, is both time-consuming and not likely to give you the results you're after.
High-intensity interval training (HIIT), on the other hand, offers the best of both worlds: it's quick and incredibly effective, offering maximized calorie burn, optimized fat burning and other benefits (like increased production of human growth hormone (HGH), also known as "the fitness hormone").
The American College of Sports Medicine, which recommends 20 minutes of more vigorous activity three days per week, even notes that HIIT workouts tend to burn 6 percent to 15 percent more calories compared to other workouts, thanks to the calories you burn after you exercise.1
Even for HIIT, however, there are variations among workouts, and it's important to find one that works right for you. If you're very fit and want to take your workout to the next level, Tabata Training is one HIIT workout to try.
It's extreme, so it's not for everyone, but even those who aren't super fit can benefit from doing a toned-down version.
Tabata Training: Four Minutes of All-Out Effort
Tabata Training, named after a researcher in sports and health fitness, Izumi Tabata, who worked with an Olympic coach who pioneered the idea for Olympic speed skaters. Tabata calls for just 20 seconds of all-out drop-dead effort, followed by a mere 10 seconds of rest. This intense cycle is repeated eight times for a total of just four minutes.
You can do Tabata Training with a number of different exercises, including an elliptical machine, a stationary bike, rowing and even bodyweight exercises like squats.
However, because the workout moves so fast, you'll want to choose an exercise you can do quickly and safely (and you'll probably want to focus on just one exercise per session, such as sprinting or squats, rather than attempting to incorporate multiple movements).
Get fit in four minutes? It sounds hard to believe, but understand that this could easily be the hardest four minutes you'll ever experience, workout-wise. With only 10 seconds of rest in between the high-intensity sessions, this isn't a workout for the faint of heart (literally and figuratively!).
This is because, if you do it correctly, your body doesn't have enough time to fully recover between the high-intensity sets. As noted by Greatist:2
"By taking rest periods only half the length of the intense bursts (a 2:1 work-to-rest ratio), the body is forced to perform without a full recovery. Translation: At some point between rounds six and eight, you'll hit a point of maximum oxygen intake and be really (really) out of breath."
That being said, if you're fit and you're willing to tough it out, you could stand to reap some significant benefits. Research shows Tabata Training works "both the anaerobic and aerobic energy releasing systems almost maximally," which is what you need for optimal cardiovascular benefit.
Boost Your VO2 Max and Trigger Mitochondrial Biogenesis
When the Tabata Method was performed four times per week for six weeks, participants in one experiment increased their anaerobic capacity by 28 percent, and their VO2 max (an indicator of cardiovascular health) and maximal aerobic power by 15 percent.
This is in contrast to the control group, who performed an hour of steady cardiovascular exercise on a stationary bike five times a week. These participants improved their VO2 max by just 10 percent, and their regimen had no effect on their anaerobic capacity.3
The workout even activates mitochondrial biogenesis, or the formation of new mitochondria, in skeletal muscle, a decline of which is common in aging.4 In an interview with Muscle & Fitness, Tabata explained how it's possible to get results in such a short period of time:5
" … Tabata not only burns the same calories in four minutes as an hour of steady-state exercise (biking or jogging), but there's also a significant 'after burn' effect, where an additional 150 calories are being burned up to 12 hours after you leave the gym.
… Tabata training — if done correctly — is very demanding during that four minutes, and the body responds to this stress by rapidly increasing its capacity to increase oxygen uptake, which is the best measurement we have of fitness."
When asked how many of the four-minute circuits were recommended for a single workout, Tabata responded with a resounding one:6
"If you are doing Tabata correctly (and many people do not) you would only be able to ever do one round of it — and indeed you'd be unlikely to even finish that before complete exhaustion set in!"
During a typical HIIT workout, The American Council on Exercise (ACE) notes, "training is done at a submaximal level; around 80 to 95 percent of maximal aerobic capacity."7 With Tabata Training, your level of exertion is even higher, approaching 100 percent or more of your maximal aerobic capacity.
Put another way, on an exertion scale of 1 to 10, a typical moderate-intensity workout (such as running or stair climbing) would be an exertion level of 5 to 6. A typical HIIT workout is done at an exertion level of 7 or higher. Tabata Training is an exertion level of 10.
It's Possible to Get Fit in Less Time
If you like the idea of slashing your workout time and still getting fit, it can be done (and you don't necessarily have to go as extreme as Tabata Training to do it). Just 12 minutes a week, or four minutes a day for three days was all it took to improve fitness levels in overweight inactive middle-aged men.
For the study, one group of men followed a protocol known as 4x4 training, completing four intervals of four minutes of high-intensity exercise (16 minutes a day, the "16-minute group") three times a week for 10 weeks.
The second group exercised three times a week using 4-minute high-intensity sessions, for a total of just 12 minutes of exercise a week, or just four minutes a day (the "4-minute group").8
Both groups showed marked improvements. The 4-minute group had a 10 percent increase in VO2max compared to a 13 percent increase in the 16-minute group. The 4-minute exercisers also experienced decreases in their blood pressure levels at amounts even greater than the 16-minute group.
Those who exercised in 16-minute sessions did have greater reductions in cholesterol and body fat than the 4-minute exercisers. However, even 16 minutes of exercise three times a week should be easily attainable by most people. Other research has shown participants were able to improve their insulin sensitivity an average of 24 percent with as little as three minutes of HIIT per week.9 Further, according to ACE, the benefits of HIIT include:10
- Significantly increased aerobic and anaerobic fitness
- Decreased fasting insulin and increased insulin sensitivity
- Reduced abdominal and subcutaneous (just under the skin) fat
Try This HIIT Workout First
If you're new to high-intensity interval training, don't go directly to a full Tabata workout. Instead, try the Peak Fitness method of 30 seconds of maximum effort followed by 90 seconds of recuperation. When repeated eight times, and including a four-minute warm-up, this workout takes about 20 minutes.
When you're first starting out, depending on your level of fitness, you may only be able to do two or three repetitions of Peak Fitness. That's OK! As you get fitter, just keep adding repetitions until you're doing eight. And if six is what your body is telling you, then stop there. If you have a history of heart disease or any medical concern please get clearance from your health care professional to start this.
Most people of average fitness will be able to do it though; it is only a matter of how much time it will take you to build up to the full eight reps, depending on your level of intensity. For a demonstration using an elliptical machine, please see the video above.
Since that video was filmed, I've incorporated Buteyko breathing into the workout, which means I do most of the workout by only breathing through my nose. This raises the challenge to another level. Here are the core principles:
- Warm up for three minutes
- Exercise as hard and fast as you can for 30 seconds. You should be gasping for breath and feel like you couldn't possibly go on another few seconds. It is better to use lower resistance and higher repetitions to increase your heart rate
- Recover for 90 seconds, still moving, but at slower pace and decreased resistance
- Repeat the high-intensity exercise and recovery seven more times. (When you're first starting out, depending on your level of fitness, you may only be able to do two or three repetitions of the high-intensity intervals. As you get fitter, just keep adding repetitions until you're doing eight during your 20-minute session)
- Cool down for a few minutes afterward by cutting down your intensity by 50-80 percent
You'll know you've pushed yourself hard enough if you reach these markers:
- It will be relatively hard to breathe and talk because you are in oxygen debt
- You will start to sweat. Typically this occurs in the second or third repetition unless you have a thyroid issue and don't sweat much normally
- Your body temperature will rise
- Lactic acid increases and you will feel a muscle "burn"
For another alternative, try Super Slow strength training. It may even be more effective than Peak Fitness cardio. While they both are highly effective, you can generate a higher cardiac output with Super Slow training as discussed in my interview with Dr McGuff. You can also try a toned down version of Tabata Training by cutting the time in half or dropping your exertion level down a couple of notches.
You Only Need to Do HIIT Two or Three Times a Week
Doing HIIT more frequently than two or three times a week can be counterproductive, as your body needs to recover between these intense sessions. If you feel the urge to do more, make sure you're really pushing yourself as hard as you can during those two or three weekly sessions, rather than increasing the frequency. Remember, intensity is KEY for reaping all the benefits interval training can offer.
Finally, when it comes to shedding unwanted pounds and reworking your fat-to-muscle ratio, HIIT combined with intermittent fasting is a winning combination that I don't think can be beat. When you combine these two strategies, especially if you exercise in a fasted state, it effectively forces your body to shed fat because your body's fat-burning processes are activated by exercise and lack of food.