A worldwide survey on fitness trends revealed high-intensity interval training, otherwise known as HIIT, to top the list in 2018 (Walter, 2017). So, what is HIIT? It is a new way of training which involves short bursts of high-intensity energy input followed by short periods of rest or recovery. HIIT is different from continuous cardiovascular exercise or steady state cardio (e.g. one hour jogging) which is usually performed at 60-80% heart rate maximum for 30 minutes or more. In this blog post, we will discuss the many benefits of HIIT and provide a sample of full body HIIT workout.
HIIT Physiological Benefits: Better Body Function and Composition
HIIT has been demonstrated to elicit positive acute and chronic physiological responses (Boutcher, 2011). Some of these improvements are seen in the metabolic profile (e.g. decreased insulin resistance), cardiorespiratory function (i.e. anaerobic and aerobic fitness), hormone production (e.g. increased growth hormone), and sports performance. These are not the only reasons HIIT has been suggested to be superior to continuous exercise! Improved body composition, considerably one of the major reasons that we exercise, can be more easily achieved through HIIT. Studies by Tremblay et al. (1994) and Trapp et al. (2008) found that HIIT reduced significantly more subcutaneous fat and abdominal fat than continuous cardiovascular exercise. Some of the possible mechanisms underlying the observation were the increased in-exercise and post-exercise fat oxidation and decreased post-exercise appetite.
HIIT’s Social Benefits: More Fun and Saves Time
The Centre of Disease Control and Prevention listed some of the most commonly perceived barriers to physical activity participation: lack of time and lack of motivation (“Overcoming Barriers”, 2011). HIIT could potentially help overcome these barriers! Typically requiring only half the duration of continuous cardiovascular exercise, HIIT workouts can be as short as 10-30 minutes. Furthermore, because the stimulus is constantly changing during the workout, HIIT is often rated as more enjoyable than the traditional cardio. Depending on the structure of workout, partner exercises and interactive drills can also be incorporated to spice up the gym session. All these factors combined contribute to higher exercise adherence and a healthier body and mind.
HIIT Psychological Benefits: Better Mood and Brain Function
Exercising stimulates us to release endorphins and Brain-Derived Neurotrophic Factors (BDNF), and makes us happier. Exercising also improves our fitness and makes us feel more confident. These are nothing new. HIIT, however, brings more benefits than that. Following a 10 minute HIIT workout, participants performed significantly better on a cognitive task (Hwang, 2016). After all, HIIT seems to be a mode of exercise that simultaneously trains the body and the mind!
Sample 20-min HIIT Workout
High Intensity Interval Training (20min):
Circuit A
TRX chest press (40 seconds)
Rest (15 seconds)
Kettlebell swing (40 seconds)
Rest (15 seconds)
Renegade row (40 seconds)
Rest (15 seconds)
Body Squat (15 seconds)
Rest (15 seconds)
Plank (40 seconds)
Rest (15 seconds)
Repeat circuit A
Circuit B
Burpees (40 seconds)
Rest (15 seconds)
Jumping jacks (40 seconds)
Rest (15 seconds)
Mountain climbers (40 seconds)
Rest (15 seconds)
Speed skaters (40 seconds)
Rest (15 seconds)
Skipping (40 seconds)
Rest (15 seconds)
Repeat Circuit B
Cool down (5-10 min):
Brisk walk on the treadmill
Word of Caution: HIIT Is Not for Everyone
As HIIT is a strenuous workout, it is not recommended for exercisers who are not physically fit and beginners who are not familiar with complex movements. HIIT participation for these exercisers may lead to muscle soreness, injury, drowsiness, diminished confidence, and even rhabdomyolysis.
Final Remarks
It is not hard to imagine why HIIT is once again number 1 on the list of Fitness Trends. To learn more about how to start a HIIT workout, drop by the gym to chat with our trainers or simply sign up for one of the classes!
About the author:
Kevin Cheng is a personal trainer at Function Health Club and the fitness instructor for the Monday evening HIIT class. He is a BSc. Kinesiology graduate from McGill University, registered BCAK kinesiologist, certified ACSM personal trainer, and published researcher. Kevin specializes in strength & conditioning, functional training, and active rehabilitation.
References
Hwang J, Brothers RM, Castelli DM, et al. Acute high-intensity exercise-induced cognitive enhancement and brain-derived neurotrophic factor in young, healthy adults. Neurosci Lett. 2016; 630:247-53.
Overcoming Barriers to Physical Activity. (2011, February 16). Retrieved October 29, 2017, from http://www.cdc.gov/physicalactivity/basics/adding–pa/barriers.html
Thum, J. S., Parsons, G., Whittle, T., & Astorino, T. A. High-Intensity Interval Training Elicits Higher Enjoyment than Moderate Intensity Continuous Exercise. PLoS ONE. 2017; 12(1), e0166299. http://doi.org/10.1371/journal.pone.0166299
Trapp EG, Chisholm DJ, Freund J, Boutcher SH. The effects of high-intensity intermittent exercise training on fat loss and fasting insulin levels of young women. International Journal of Obesity. 2008; 32(4):684–691.
Tremblay A, Simoneau J-A, Bouchard C. Impact of exercise intensity on body fatness and skeletal muscle metabolism. Metabolism. 1994;43(7):814–818.
