Anybody who’s trained with me knows that I LOVE high-intensity interval training, or HIIT. It prevents boredom, provides a challenge, and works well with many different types of exercises. Plus it’s super-efficient. While I still do traditional endurance training and bodybuidling routines, most of my workouts are in a HIIT format, and there are good reasons why. In this article, I delve into the evidence supporting HIIT training and how it compares to traditional routines.
What is HIIT?
High-intensity interval training, or HIIT, is a style of training that consists of short periods of maximum or near-maximum effort followed by brief recovery periods. The exercise intervals vary, but are typically 10 to 30 seconds and are followed by short recovery periods consisting of a lower-intensity exercise or resting. An example would be as follows:
Push-ups: 30 seconds
Rest: 10 seconds
Squats: 30 seconds
Rest: 10 seconds
Crunches: 30 seconds
Rest: 10 seconds
Repeat twice more
Benefits of HIIT
Results in greater improvements in VO2 max (an indicator of exercise capacity) than traditional endurance training (Milanovic). This means that over time you are able to work harder and potentially burn more calories during your workout.
Creates the same improvements in skeletal muscle oxidative capacity as traditional endurance training in less time (Gibala). Even with its shorter workouts, HIIT training still induces metabolic changes in your muscle that result in increased endurance and improved exercise performance.
Reduces insulin resistance and improves glucose control in people with type 2 diabetes (Little, Jelleyman). HIIT training causes metabolically active tissues to become more responsive to insulin, which in turn causes cells to take up glucose which is used for energy.
Increases the capacity for fat oxidation during exercise (Talanian, Perry). In other words, your muscles become more effective at using fat for fuel during exercise.
Improves vascular function to a greater extent than medium-intensity continuous training (Ramos). Vascular dysfunction is associated with adverse cardiovascular events, such as heart attacks and strokes.
Has a greater effect on excess post-exercise oxygen consumption (EPOC) than low- to moderate-intensity exercise. After exercise, the body will continue to take up extra oxygen for a period of time, expending more energy in the process, known as EPOC. The magnitude and duration of EPOC is affected by the intensity of exercise (Bersheim, LaForgia).
Almost any type of exercise can be incorporated into a HIIT routine. HIIT is ideal for people who want to work a lot of different muscle groups in a very short period of time. Plus, it’s fun! So consider replacing some of those stale, monotonous treadmill and elliptical workouts with HIIT. You’ll be glad you did.
Bersheim, E. and Bahr, R. (2003). Effect of exercise intensity, duration and mode on post-exercise oxygen consumption. Sports Medicine, 33, 14, 1037-1060
Gibala, M.J., J.P. Little, M. van Essen, G.P. Wilkin, K.A. Burgomaster, A. Safdar, S. Raha, and M.A. Tarnopolsky. Short-term sprint interval versus traditional endurance training: similar initial adaptations in human skeletal muscle and exercise performance. J. Physiol. 575(Pt 3):901-911, 2006
High-intensity interval training. (n.d.). Retrieved April 13, 2016, from https://en.wikipedia.org/wiki/High-intensity_interval_training
Jelleyman C, Yates T, O’Donovan G, Gray LJ, King JA, Khunti K, Davies MJ (November 2015). “The effects of high-intensity interval training on glucose regulation and insulin resistance: a meta-analysis”. Obes Rev (Meta-Analysis) 16 (11): 942–61. doi:10.1111/obr.12317.PMID 26481101.
LaForgia, J., Withers, R. and Gore, C. (2006). Effects of exercise intensity and duration on the excess post-exercise oxygen consumption. Journal of Sport Sciences, 24, 12, 1247-1264.
Little JP, Gillen JB, Percival ME, Safdar A, Tarnopolsky MA, Punthakee Z, Jung ME, Gibala MJ. Low-volume high-intensity interval training reduces hyperglycemia and increases muscle mitochondrial capacity in patients with type 2 diabetes. J Appl Physiol 111: 1554 –1560, 2011. First published August 25, 2011; doi:10.1152/japplphysiol.00921.2011.
Milanović Z, Sporiš G, Weston M (October 2015). “Effectiveness of High-Intensity Interval Training (HIT) and Continuous Endurance Training for VO2max Improvements: A Systematic Review and Meta-Analysis of Controlled Trials”. Sports Med (Systematic Review and Meta-Analysis) 45 (10): 1469–81. doi:10.1007/s40279-015-0365-0. PMID 26243014.
Perry CG, Heigenhauser GJ, Bonen A, Spriet LL. High-intensity aerobic interval training increases fat and carbohydrate metabolic capacities in human skeletal muscle. Appl Physiol Nutr Metab. 2008 Dec;33(6):1112-23. doi: 10.1139/H08-097.
Ramos JS, Dalleck LC, Tjonna AE, Beetham KS, Coombes JS (May 2015). “The impact of high-intensity interval training versus moderate-intensity continuous training on vascular function: a systematic review and meta-analysis”. Sports Med (Systematic Review and Meta-Analysis) 45 (5): 679–92. doi:10.1007/s40279-015-0321-z. PMID 25771785.
Talanian JL, Galloway SD, Heigenhauser GJ, Bonen A, Spriet LL. Two weeks of high-intensity aerobic interval training increases the capacity for fat oxidation during exercise in women. J Appl Physiol 102: 1439 –1447, 2007. First published December 14, 2006; doi:10.1152/japplphysiol.01098.2006