High-Intensity Interval Training or “HIIT” is a great way to reap many of the benefits of aerobic exercise in a shorter time frame. HIIT is preferred by many individuals with busy schedules who do not have time to have a full workout at the gym. This is because HIIT sessions are rather short (typically less than 30 minutes) and can be done at home or outside without expensive equipment.
HIIT has been part of the fitness world for a long time and its benefits are well acknowledged by the clinical setting. Experts at the Mayo Clinic even recommend it to patients recovering from coronary artery disease (CAD) and diabetes after an exercise test and medical evaluation has been performed.
What is HIIT?
HIIT is an exercise technique that consists of short bursts of high-intensity exercise followed by brief periods of rest. An example of this would be 20 seconds of high-intensity jumping jacks followed by a 10-second rest period.
The exact timing and order of these rest and high-intensity periods are subjective and can be arranged in many ways. A common method is to complete 30 seconds of exercise followed by 30 seconds of rest. Another popular technique is simply to add periods of high-intensity exercise to a preexisting aerobic exercise routine.
The point is to exercise at a level closer to maximum exercise capacity (usually measured by VO2) than would be achieved with moderate exercise. Moderate exercise, like walking briskly, requires around 50% exercise capacity. The goal of HIIT is to use closer to 90%.
How is it Different from Regular Cardio?
During regular cardio or aerobic exercise, one must steadily exercise at a moderate/vigorous intensity for at least 30 minutes. When HIIT is adopted, we engage in intervals of high-intensity exercise followed by rest or lower intensity exercise. The high-intensity intervals allow us to harvest benefits in a shorter time period.
HIIT is also often considered a lot more fun than regular aerobic exercise as it can incorporate drills like squats, lunges, and jumping jacks into the mix. Many push themselves to the limit during the high-intensity intervals and may feel more fatigued after a workout than would with regular aerobic exercise.
Health benefits from HIIT are similar to those of aerobic exercise, including lower blood pressure and heart rate, fat burning, and building lean muscle. Exercise, in general, is also known to improve cognition, regulate blood sugar, lower stress, and reduce the risk for chronic diseases. For some individuals, HIIT yields even greater results than regular aerobic exercise but this is subjective.
Is It Right for Me?
HIIT can be adopted by anyone, not just athletes and the super fit. In fact, HIIT might prove more beneficial to individuals who normally don’t have time for a full workout. This technique allows them to improve their fitness level without having to make major changes in their schedule.
Elderly individuals and recovering patients should be more careful when adopting HIIT, especially during high-intensity exercise. When in doubt, consult a physician or a personal trainer to figure out what exercises are safe and which are risky.
- Gormley, Shannan E, et al., “Effect of Intensity of Aerobic Training on VO2max.” Medicine and Science in Sports and Exercise, U.S. National Library of Medicine, July 2008, www.ncbi.nlm.nih.gov/pubmed/18580415.
- Solheim, Tanner J, et al. VO2 Reserve vs. Heart Rate Reserve During Moderate Intensity Treadmill Exercise. International Journal of Exercise Science, www.ncbi.nlm.nih.gov/pmc/articles/PMC4831852/.
- Kaminsky, David A, et al. “Assessing Maximal Exercise Capacity: Peak Work or Peak Oxygen Consumption?” Respiratory Care, U.S. National Library of Medicine, Jan. 2014, www.ncbi.nlm.nih.gov/pubmed/23777656.