High Intensity Interval Training, abbreviated to HIIT, is a combination of high-intensity exercise followed by a period of recovery or reduced intensity. The “on” phase, or high-intense phase may last between 10 seconds to 4 minutes and the “off” phase may last the same amount of time, less, or more dependent on the goals of the program. HIIT training may elicit many health benefits, including increased cardiovascular fitness, improving abdominal and body fat, increasing lean muscle mass, improving metabolic rate and many more.
So how does HIIT save time in the gym? The benefits of HIIT are very similar to that of continuous aerobic exercise; however they can be achieved in half the time due to the higher intensity bouts of exercise where the body burns more calories during your session and after. By increasing your heart rate, your body will continue to burn more calories even after you finish your workout to restore your body back to resting levels.
The physical activity recommendations for adults include 30 minutes of moderate-intensity aerobic exercise five days per week or 20 minutes of vigorous aerobic exercise three times per week, or a combination of both, in conjunction with two strength training sessions per week. High Intensity Interval Training works the vigorous end of guidelines spectrum, therefore saving time and frequency of your weekly sessions.
Professor Martin Gibala from McMaster University in Hamilton Ontario conducted a study that looked at the benefits of 10 minutes of interval training cardiovascular. His protocol included a 2 minute warm up, a 20-second sprint followed by 2-minutes of recovery three times through and finishing with a couple of minutes cool down. He compared this protocol to the benefits of 50-minutes continuous moderate-intense cycling and found very similar benefits in cardiorespiratory fitness and insulin sensitivity in 12-weeks despite the fact that the interval training group exercised 5 fold less than the continuous group.
As interval training involves high intensity exercise, it is important to receive medical clearance from your GP to prevent any adverse events from a sedentary lifestyle and a base level of cardiorespiratory fitness is recommended. However this form of training is easily modified and appropriate for all ages.
Written by May Warrick (Exercise Physiologist/ Corrective Exercise Practitioner)