Over the past few years, high-intensity interval training (HIIT) has exploded onto the fitness scene. Chances are you offer HIIT group exercise classes or personal trainers use these methods when training clients within your recreation center.
And while HIIT is known to have some serious benefits such as increased caloric expenditure due to excess post-exercise oxygen consumption (EPOC), is the format beneficial to fitness newcomers?
The American Council on Exercise (ACE) commissioned an independent study from researchers at the University of Wisconsin La Crosse to compare the physiologic responses of two HIIT workouts — Tabata and less intense interval training — with steady-state cardio exercise in previously inactive young adults.
In the study led by Carl Foster, researchers recruited 65 relatively sedentary young adults between the ages of 18 and 28 who hadn’t exercised more than twice a week at a low-to-moderate intensity in the previous three months.
The first group performed 20 minutes of steady state, moderate-to-vigorous intensity exercise on a stationary bike. The second performed four minutes of Tabata training in sets of 20 seconds of high intensity exercise followed by 10 seconds of unloaded recovery pedaling. The third group performed 20 minutes of interval training consisting of 30 seconds of intense exercise followed by 60 seconds of recovery pedaling. Each week participants rated their enjoyment level of the exercise program.
The study revealed that the HIIT workouts didn’t produce significantly greater improvements in markers of aerobic and anaerobic exercise performance compared to steady-state cardio for sedentary young adults. Participants of all groups did see improvements in cardiorespiratory health — VO2max and body-weight — at a very similar rate over the course of the eight-week study. However, the Tabata group indicated the lowest amount of enjoyment with the exercise program.
“Arguably, one of the more interesting findings of this study was the significantly lower level of enjoyment reported by individuals in the Tabata training group compared to the other two training groups,” said Cedric Byrant, ACE Chief Science Officer. According to ACE, this lower level of enjoyment associated with Tabata workouts could potentially result in poor long-term adherence to the exercise program.
Bottom line: For fitness newcomers who were previously sedentary, HIIT has similar effects as steady-state cardio. Both forms of exercise can improve cardiovascular health. However, Tabata may not be the best choice for everyone. As the study showed, these shorter intervals were less enjoyable.