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High Intensity Interval Training: What’s New and Exciting?

High intensity interval training (HIIT) is, by no means, a new phenomenon in sports and fitness. It has been used by athletes for performance enhancement since 1912. Perhaps the most famous HIIT protocol was done by Izumi Tabata (1996) in which he investigated if a 4-minute HIIT protocol could improve V02max and anaerobic power, which it did. Since Tabata published his research, hundreds of other researchers have completed HIIT studies to investigate the effects on fitness, fat reduction, insulin sensitivity, feelings of energy, reductions in blood pressure, weight loss, V02, anaerobic power, decreases in waist and hip circumference, and the list goes on and on. In regard to using HIIT for fitness clients, this article will investigate the newest, and most exciting, HIIT protocols.

Learning Objectives

  1. Understand that HIIT has been used by athletes since 1912.
  2. Practice new HIIT protocols to improve the fitness of clients.
  3. Describe the most exciting HIIT protocols as they relate to improvements in fitness.

History of HIIT

Many fitness professionals may not realize that HIIT has been used for improving sports performance since 1912. The Finnish middle-distance runner, Hannes Kolehmainen, was the first recorded athlete to use HIIT. He used running intervals at race pace with a walking recovery to prepare for the 1912 Olympics, at which he won three Gold medals in middle distance races. In 1937, Swedish running coach Gosta Holmer started another form of HIIT called ‘Fartlek Training’ for his runners. Fartlek means “speed play.” It is continuous running with sprints of 50m to 3000m. Coach Holmer did his Fartlek training with 10 – 30 athletes running on hiking trails where the last person in line had to sprint to the front of line while the other runners ran at a slower pace. In 1952, Emil Zatopek, a Czechoslovak long-distance runner, used sprints with jog recoveries to prepare for the 1952 Helsinki Olympics. He won Gold medals in the 5000 meters, 10,000 meters, and the marathon (Bracko, 2018).

In the fitness realm, one of the first HIIT studies was done by Tremblay, Simoneau, & Bouchard (1994). They found that HIIT reduced skin folds nine times more than medium intensity continuous training (MICT). And then, of course, perhaps the most famous HIIT study was done by Izumi Tabata (yes that Tabata) in 1996 (yes 23 years ago). Considering why Tabata did his research, the notoriety Tabata has received in the fitness industry, may not be deserved. Tabata did his HIIT research to see if the Japanese speed skating team could decrease their training volume, increase training intensity, and still win medals. The physical education students who were subjects in Tabata’s study increased their V02max by 7 ml/kg/min and their anaerobic capacity by 28%.

Interestingly, the author has experienced an interesting misunderstanding about HIIT and Tabata when presenting at some fitness conferences. Some fitness professionals have the misunderstanding that HIIT is Tabata, and Tabata is HIIT. Some fitness professionals do not understand that Tabata is just one of hundreds of HIIT protocols.

New and Exciting HIIT Research

Chin, et al. (2019) investigated differences in frequency of HIIT programming. Fifty-six overweight or obese men (18 - 30 years) were in one of the following groups: control - no exercise, medium intensity continuous training (MICT) three times/week, HIIT three times/week, HIIT twice/weekly, and HIIT once/week. Each HIIT session consisted of 12, 1-minute bouts at 90% heart rate reserve (HRR), interspersed with 11, 1-minute bouts at 70% HRR. Aerobic capacity, body composition, resting heart rate, vascular function, insulin resistance, and biomarkers of metabolic syndrome risk factor were examined at baseline, 4 weeks, and 8 weeks. The results are quite exciting. Aerobic capacity and percent fat-free mass significantly increased in all exercise groups. Body fat mass and systolic blood pressure significantly decreased after 8 weeks in all exercise groups. Body fat mass significantly decreased after 4 weeks in all HIIT groups but not in the MICT group. The authors conclude that low-frequency HIIT might be effective as an initial exercise program for inactive, overweight or obese young men.

Seo, et al, (2019) investigated the effect of HIIT with different work-to-rest ratios on 47 male Taekwondo athletes (15-18 yrs). Subjects were put into one of three HIIT groups or a control group. Each group performed 6 and 8 bouts of HIIT: 1) 30-seconds work, 60-seconds rest), 2) 30-seconds work, 120-seconds rest, and 3) 30-seconds work, 4-minutes rest. The control group performed normal Taekwondo training. All HIIT groups completed 10 sessions in 4 weeks. VO2max improved significantly in all HIIT groups. The HIIT with 30-second work/120-second rest improved anaerobic capacity. The authors indicate that HIIT can be effective in improving the fitness of adolescent Taekwondo athletes.

Pymer, et al., (2019) conducted a review of research to investigate the effect of HIIT on patients who have intermittent claudication (IC), which is the most common symptom of peripheral arterial disease. Intermittent claudication adversely affects walking ability, functional capacity and quality of life. The most common way for patients with IC to improve their fitness is a supervised exercise program (SEP). However, the time it takes to do a SEP is what most patients claim as the biggest barrier to participation. Therefore, the researchers wanted to see if HIIT, being more time efficient than SEPs, could be an alternative form of exercise.

In their review, the researchers found eight studies which found that HIIT appears to improve walking distances and oxygen uptake, with improvements in 6 weeks. HIIT was compared with the longer training programs, and as countless other researchers have found, the short HIIT programs produced the same benefit as the longer programs.

RezkAllah and Takla (2019) conducted a study to compare the effect of low-volume HIIT (LV-HIIT) to high-volume HIIT (HV-HIIT) on average blood glucose (ABG) levels over the past 3 months and fasting blood glucose (FBG) in overweight adults with prediabetes. The exercise groups included: 1) LV-HIIT group (10, 1-minute intervals at 90% HRmax with 1-minute active recovery, total exercise of 25 minutes/session), 2) HV-HIIT group (4, 4-minute intervals at 90% of HRmax with 3 minutes of active rest, total exercise of 40 minutes/session), and 3) no exercise control group. Both training programs were 3 sessions/week for 12 weeks. LV-HIIT and HV-HIIT significantly reduced ABG and FBG, however HV-HIIT reduced ABG and FBG more than LV-HIIT. The researchers conclude that HIIT was more effective for glycemic control in prediabetes, with HV-HIIT being better than LV-HIIT to reduce ABG, FBG, and progression to type 2 diabetes in young adults with prediabetes.

Chrøis, (2019) wanted to look at the effects of HIIT on mitochondrial respiratory capacity and mitochondrial content in older females and males. Twenty-two older sedentary males and females did 6 weeks of HIIT 3 days/week. The HIIT protocol included: 5, 1-minute at maximum intensity cycling with 90-seconds recovery. The results indicate ⩒O2max increased and body fat percentage decreased in both sexes. There was increased mitochondrial content, which may help to maintain muscle oxidative capacity and slow down the process of sarcopenia (loss of muscle mass) with aging.


Bracko, M.R., (2018). Create Amazing HIIT Workouts with No Equipment, Fitness Presentation, SaskFit, Saskatoon, SK.

Chin, E.C., et al. (2019). Low-Frequency HIIT Improves Body Composition and Aerobic Capacity in Overweight Men. Medicine and Science in Sports and Exercise Jul 19. doi: 10.1249/MSS.0000000000002097. [Epub ahead of print]

Chrøis, K.M., et al. (2019). Mitochondrial adaptations to high intensity interval training in older females and males. European Journal of Sport Science. 30:1-11.

Pymer, S. et al. (2019). A systematic review of high-intensity interval training as an exercise intervention for intermittent claudication. Journal of Vascular Surgery. Jun 27. pii: S0741-5214(19)31035-3. doi: 10.1016/j.jvs.2019.03.050. [Epub ahead of print]

RezkAllah, S.S. and Takla, M.K. (2019). Effects of Different Dosages of Interval Training on Glycemic Control in People with Prediabetes: A Randomized Controlled Trial. Diabetes Spectrum. 32(2):125-131.

Seo, M.W., et al. (2019). Effects of Various Work-to-rest Ratios during High-intensity Interval Training on Athletic Performance in Adolescents. International Journal of Sports Medicine, 40(8):503-510.

Tabata, et al. (1996). Effects of moderate-intensity endurance and high-intensity intermittent training on anaerobic capacity and VO2max. Medicine and Science in Sports and Exercise, 28 (10): 1327–30, 1996

Tremblay, Simoneau, & Bouchard. (1994). Impact of Exercise Intensity on Body Fatness and Skeletal Muscle Metabolism. Metabolism 43(7): 814–818.