Tabata vs HIIT: What the Original Study Did and How to Time It

"Tabata" has become a name for any workout with 20 seconds on and 10 seconds off. The original was something narrower and much harder: a cycling test so intense that people couldn't finish the eighth round.

Knowing what the study did helps you decide what you're actually doing when you set a timer to 20/10, and whether a different format would suit you better.

What the original study did

In 1996, Izumi Tabata and colleagues at Japan's National Institute of Fitness and Sports published two training experiments on a mechanically braked exercise bike in Medicine & Science in Sports & Exercise.

Experiment 1: steady endurance. Participants trained at 70% of their VO₂max (their maximal oxygen uptake) for 60 minutes a day, 5 days a week, for 6 weeks. Their VO₂max rose from 53 to 58 ml/kg/min, but their anaerobic capacity, measured as the maximal accumulated oxygen deficit, did not change significantly.

Experiment 2: the intervals. Seven participants trained 5 days a week for 6 weeks. Each session was 7 to 8 sets of 20 seconds at about 170% of VO₂max, with 10 seconds of rest between them. That intensity is far above anything you could hold: in his 2019 review, Tabata describes 170% of VO₂max as a load that would exhaust someone in about 50 seconds of continuous pedalling. The review also gives the weekly detail: 4 days of the full, exhausting protocol and 1 day of 30 minutes at 70% followed by 4 easier sets.

After six weeks, VO₂max had risen by 7 ml/kg/min and anaerobic capacity by 28%. The conclusion was that short, very hard intermittent training could improve both the aerobic and the anaerobic energy systems, which the moderate training hadn't.

A follow-up paper in 1997 compared that 20/10 protocol with another one used by Japanese speed skaters: 4 to 5 bouts of 30 seconds at about 200% of VO₂max with 2 minutes of rest. The 20/10 version pushed both energy systems close to their maximum; the 30-second version didn't. Both protocols came from Kouichi Irisawa, head coach of the Japanese speed skating team in the 1980s. After seeing the results, he dropped the second protocol and kept the first.

The intensity is the definition

In his 2019 review, Tabata is unusually direct about what counts. He defines Tabata training as exercise at an intensity that exhausts you during the 7th or 8th set of 20 seconds on, 10 seconds off. In the lab, exhaustion meant the pedalling rate dropped below about 85 rpm despite encouragement (the target was 90). If someone could keep going past eight sets, the load was raised; if they couldn't reach six, it was lowered.

He also points out what the protocol doesn't cover. For running and body-weight exercises such as burpees and squat jumps, he writes, the published evidence on their effects is insufficient. And he notes that 20/10 done at a walking pace "can be expected to result in no improvement" in VO₂max.

How gym "Tabata" compares

Most real-world Tabata is a 20/10 timer with body-weight moves, often several 4-minute blocks in a row. That's hard training, but it isn't the same stimulus.

A small study measured exactly this kind of session (Emberts et al., 2013). Sixteen trained volunteers did a 20-minute session: four 4-minute blocks of 20-second all-out body-weight and plyometric moves with 10-second rests. On average they worked at 86% of maximum heart rate and 74% of VO₂max, rated it "hard" (an average rating of perceived exertion of 15.4), and burned an estimated 240 to 360 kcal. The authors concluded that it met the American College of Sports Medicine's guidelines for improving cardiorespiratory fitness.

So gym Tabata is a solid, time-efficient workout. It just averages well below VO₂max, while the original work bouts were at about 170% of it. If you're doing body-weight 20/10s, call it what it is: interval training with a 20/10 timer. The results of the 1996 study don't transfer automatically.

One more myth worth dropping: Tabata training is not a proven fat-loss shortcut. In the same review, Tabata writes that the energy used during such short training is "negligible", and that the after-burn (excess post-exercise oxygen consumption) following Tabata training hasn't been measured.

Common interval formats and how to time them

Format	Work	Rest	Rounds	Time	Good for
Tabata	20 s	10 s	8	3:50 to 4:00	One very hard effort, on a bike or rower
30/30	30 s	30 s	10	10 min	A first interval session
40/20	40 s	20 s	10	10 min	Circuits of 6 to 10 exercises
45/15	45 s	15 s	8	8 min	Strength-endurance circuits
EMOM	reps at the top of each minute	rest of the minute	10+	10 min+	Strength or skill work
Boxing rounds	3 min	1 min	3 to 12	11 min+	Bag or pad work

Some notes on each:

• Tabata's length depends on where you stop. Eight rounds of 20 seconds with 10-second rests between them is 3 minutes 50 seconds of work and rest. The often-quoted "4 minutes" counts a final 10-second rest. Tabata's review recommends a 10-minute warm-up at about 50% of VO₂max before starting.
• EMOM (every minute on the minute) sets a number of reps at the start of each minute; whatever's left of the minute is your rest. Faster reps mean more rest, so it self-regulates. Pick a rep count you can finish in 30 to 40 seconds.
• Boxing rounds mirror the professional rules. The Association of Boxing Commissions' Unified Rules set each round at 3 minutes with a 1-minute rest between rounds.
• Sprint intervals with long recoveries are another proven option. In a 12-week study, sedentary men who did three 20-second all-out cycle sprints separated by 2 minutes of easy pedalling, inside a 10-minute session, three times a week, improved peak oxygen uptake by 19%, the same as a group doing 45 minutes of moderate cycling (Gillen et al., 2016). It was a small study, 9 and 10 men per group, but it shows how little hard work can go a long way when the recovery is long enough.

Where intervals fit in a week

The World Health Organization's 2020 guidelines recommend that adults do 150 to 300 minutes of moderate or 75 to 150 minutes of vigorous aerobic activity a week, or an equivalent mix, plus muscle-strengthening activity on two or more days. A 4-minute Tabata is a small part of that. A 20-minute interval class twice a week, plus some walking and strength work, gets most people a long way there.

Our workout plan builder can put the strength days around your interval sessions.

Safety

Hard intervals are safe for most healthy people, but intensity is one of the things that changes the risk. The American College of Sports Medicine's screening recommendations (Riebe et al., 2015) are built on three questions: how active you are now, whether you have signs or symptoms of, or known, cardiovascular, metabolic or kidney disease, and how hard you plan to exercise. If you're inactive and have one of those conditions, or symptoms that might point to one, check with a doctor before starting vigorous exercise.

Even then, high intensity isn't off limits. In Norwegian cardiac rehabilitation centres, 4,846 patients with coronary heart disease did 175,820 hours of supervised training. There was one cardiac arrest per 129,456 hours of moderate exercise and one per 23,182 hours of high-intensity intervals, and the authors judged the risk low for both (Rognmo et al., 2012). The key word is supervised.

Practical habits that help:

• Build up. Start with 30/30 or 40/20 at a hard-but-controlled effort before trying all-out 20/10s.
• Warm up properly. Ten minutes of easy movement first, as the original protocol did.
• Choose low-impact moves (bike, rower, step-ups) if jumping hurts your knees, ankles or back.
• Stop if something hurts, and check with a doctor before starting if you have a health condition, are pregnant or are recovering from an injury.

Time it

Our free interval timer has presets for Tabata, HIIT 30/30, 40/20, 45/15, EMOM and boxing rounds, with countdown beeps, optional spoken cues and a full-screen display you can read from across the room. Set your own work, rest, rounds and sets, and share the link: Tabata 20/10 × 8, EMOM for 10 minutes or 3 sprints with 2-minute recoveries.

Sources

• Tabata, I., Nishimura, K., Kouzaki, M., Hirai, Y., Ogita, F., Miyachi, M., & Yamamoto, K. (1996). Effects of moderate-intensity endurance and high-intensity intermittent training on anaerobic capacity and VO₂max. Medicine & Science in Sports & Exercise, 28(10), 1327–1330.
• Tabata, I., Irisawa, K., Kouzaki, M., Nishimura, K., Ogita, F., & Miyachi, M. (1997). Metabolic profile of high intensity intermittent exercises. Medicine & Science in Sports & Exercise, 29(3), 390–395.
• Tabata, I. (2019). Tabata training: one of the most energetically effective high-intensity intermittent training methods. The Journal of Physiological Sciences, 69(4), 559–572. PMC10717222
• Emberts, T., Porcari, J., Dobers-Tein, S., Steffen, J., & Foster, C. (2013). Exercise intensity and energy expenditure of a Tabata workout. Journal of Sports Science & Medicine, 12, 612–613. PMC3772611
• Gillen, J. B., et al. (2016). Twelve weeks of sprint interval training improves indices of cardiometabolic health similar to traditional endurance training despite a five-fold lower exercise volume and time commitment. PLOS ONE, 11, e0154075. PMC4846072
• Bull, F. C., et al. (2020). World Health Organization 2020 guidelines on physical activity and sedentary behaviour. British Journal of Sports Medicine, 54, 1451–1462. PMC7719906
• Riebe, D., et al. (2015). Updating ACSM's recommendations for exercise preparticipation health screening. Medicine & Science in Sports & Exercise, 47, 2473–2479.
• Rognmo, Ø., et al. (2012). Cardiovascular risk of high- versus moderate-intensity aerobic exercise in coronary heart disease patients. Circulation, 126, 1436–1440.
• Association of Boxing Commissions. Unified Rules of Boxing. abcboxing.com