High-intensity interval training (HIIT)
High-intensity interval training (HIIT), also known as high-intensity intermittent exercise (HIIE) or sprint interval training (SIT), is a popular exercise regimen that alternates short bursts of intense activity with periods of lower-intensity exercise or rest. Typically, a HIIT session begins with a warm-up, followed by multiple rounds of high-intensity effort, and concludes with a cool-down phase. This training method is designed to elevate the heart rate quickly, allowing participants to maximize fat burning in a shorter time frame compared to traditional exercise routines.
HIIT can vary in structure, but it generally involves maintaining a high level of effort for brief periods, often with recommendations to limit intense bursts to around 20 seconds. The origins of interval training date back to the late 1930s, with significant contributions from figures such as Dr. Woldemar Gerschler and later refinements from various coaches and researchers. Modern adaptations of HIIT have been shown to improve cardiovascular health, insulin sensitivity, and overall fitness levels, making it especially appealing for individuals seeking efficient workouts amidst busy schedules. This technique is commonly utilized by athletes, including sprinters and swimmers, looking to enhance performance while preserving muscle mass.
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High-intensity interval training (HIIT)
High-intensity interval training (HIIT)—also known as high-intensity intermittent exercise (HIIE) or sprint interval training (SIT)—is a type of exercise regimen used by many athletes. The exercise regimen usually begins with a warm-up period, in which a person conditions their body for a high-intensity workout. The person does several repetitions of the exercise in quick succession, and then switches to a medium-intensity version of the exercise, followed by a cool-down period. The medium-intensity version of the exercise is usually performed at around 50 percent intensity and is meant to let the muscles relax while still getting the benefit of the exercise.
The number of repetitions used in HIIT can vary from exercise to exercise or training regimen to training regimen, but no real formula exists as to how exactly an HIIT regimen needs to be performed for maximum health benefits. However, it is generally advised to do no more than three repetitions or twenty seconds of intense exercise in a row, as exceeding this limit is thought to be debilitating to the human body. Through HIIT, the body is meant to give an all-out effort for a short but intense burst. The purposes of training is to keep the body’s heart rate up consistently so that the body can burn the maximum amount of fat in the shortest amount of time.
Background
Interval training was initially developed by Dr. Woldemar Gerschler in the late 1930s. At the time, Gerschler was working as head coach of Dresdner SC, a major German sports club in the time before World War II. Gerschler attempted to base his training methods on both physiological and psychological conditioning, although he was trained more in the psychological. To perfect the technique, Gerschler recruited noted cardiologist Dr. Herbert Reindell. Between 1935 and 1940, the two experimented on more than three thousand subjects, whose precise heart rate was monitored over twenty-one days of training. In their experiments, Gerschler and Reindell found that there were great improvements in performance over this period and that the volume of the heart increased by over one-fifth.
The experiments carried out by Gerschler and Reindell helped the two doctors develop the technique known as interval training, where athletes would run short distances or lift weights for a relatively short period of time at full capacity, followed by a short recovery period. The original form of interval training was based on the idea that the volume of blood in the body is constant and that the effect gained from training at maximum capacity for a short time will come when the heart rate decreases due to the increased quantity of blood that is pumped during training.
Gerschler went on to use this technique in his coaching after World War II. Coached using Gerschler’s interval training technique, athlete Josy Barthel became the surprise winner of the men’s 1500-meter race at the 1952 Summer Olympics. This brought widespread attention to the technique, and Gerschler later coached Roger Moens in this technique to win the silver medal in the 800-meter race at the 1960 Summer Olympics.
New Interval Training
Gerschler’s technique was later refined by others. Individuals such as athletic coach Peter Coe, Professor Izumi Tabata, and Professor Martin Gibala made vast improvements to the technique. Each of these individuals came up with their own regimens based on interval training, which culminated in the formation of modern high-intensity intermittent exercise (HIIE).
In 1996, Tabata published his study on the effects of high-intensity interval training in conjunction with the National Institute of Fitness and Sports in Kanoya, Japan. In this study, Tabata followed training methods that were being used by Japanese speed skaters. He broke athletes participating in the study into two groups and monitored them over a six-day period. During the study, Tabata had one group engage in moderate-intensity exercise for one hour on an exercise bicycle; the other group trained using the method he saw Japanese speed skaters using, which was a ten-minute warm-up and a four-minute period of intense exercise and rest at a 2:1 ratio, with eight total intervals taking place. Tabata noted in the study that only the second group received a noted increase in anaerobic capacity.
In February 2012, Jamie Timmons, a professor of systems biology at the University of Loughborough, further refined the technique and debuted his take on HIIE on the BBC program Horizon, putting BBC science journalist and television host Michael Mosley through a rigorous exercise regimen that he designed. The three-minute HIIE program was shown to be effective with just six repetitions a week, with forty seconds of the regimen being done at maximum speed. Timmons has demonstrated that his approach can improve insulin sensitivity in a matter of just two weeks, and can help to prevent type 2 diabetes, obesity, and cardiovascular disease, among other conditions.
HIIT is widely used in personal training, as it is great technique to burn fat without promoting muscle loss. In athletics, HIIT is often used by sprinters and swimmers who are looking to gain stamina without losing speed or precision. In general, the technique is used by those who are looking for a quick but intense workout that fits into their lifestyle.
Bibliography
Little, Jonathan P., et al. "A Practical Model of Low-Volume High-Intensity Interval Training Induces Mitochondrial Biogenesis in Human Skeletal Muscle: Potential Mechanisms." Journal of Physiology 588.6 (2010): 1011–022. Print.
Laursen, Paul B., and David G. Jenkins. "The Scientific Basis for High-Intensity Interval Training: Optimizing Training Programs and Maximizing Performance in Highly Trained Endurance Athletes." Sports Medicine 32.1 (2002): 53–73. Print.
Mosley, Michael, and Peta Bee. "A Few Workouts and Tips." Fast Exercise. Author, n.d. Web. 24 Aug. 2016.
Reynolds, Gretchen. "One Minute of All-Out Exercise May Have Benefits of 45 Minutes of Moderate Exertion." New York Times. New York Times, 27 Apr. 2016. Web. 24 Aug. 2016.
Song, Xu, et al. "Comparative Effects of High-Intensity Interval Training and Moderate-Intensity Continuous Training on Weight and Metabolic Health in College Students with Obesity." Scientific Journal, vol. 14, no. 16558, 17 July 2024, doi.org/10.1038/s41598-024-67331-z. Accessed 13 Dec. 2024.
Tabata, I., et al. "Effects of Moderate-Intensity Endurance and High-Intensity Intermittent Training on Anaerobic Capacity and VO2max." Medicine and Science in Sports and Exercise 28.10 (1996): 1327–30. Print.