A Best HIIT Protocol?

High-intensity interval training seems all the rage these days, as both anecdotal information and scientific evidence support its claims to be an efficient and effective form of exercise. However, many experts are concerned that deconditioned clients may think the programming is too tough. Is there a way to facilitate HIIT sessions that doesn’t leave novice exercisers feeling overwhelmed?
A new study says yes.

Reported in Medicine & Science in Sports & Exercise (2015; 47 [5], 1038–45), the study included 20 overweight and deconditioned people around 22 years of age. Participants completed several types of high-intensity training. The first was a 20-minute continuous workout without a rest. The other three workouts lasted 24 minutes each and featured a 1:1 work-to-rest ratio of 30 seconds, 60 seconds and 120 seconds, respectively. The goal was to determine perceived exertion ratings (RPE) for all four workouts.

Before the training began, participants anticipated that the 120-second protocol would require the greatest exertion. During all workouts, RPE increased from beginning to end. The highest overall perceived exertion resulted from the continuous workout, followed by the 120-second protocol. The 30-second protocol produced the lowest RPE of the interval scenarios, despite producing the same volume of work as the other protocols.

The authors believe that these data may be beneficial in attracting more people to participate in—and benefit from—HIIT. “These findings suggest that 30-[second HIIT] protocols limit the perceptual drift that occurs during exercise, in comparison to [heavy continuous] exercise,” they explained. “Moreover, performing more intervals of shorter durations appears to produce lower postexercise RPE values than performing fewer intervals of longer duration and equal intensity. Because effort perception may influence behavior, these results could have implications for the prescription of interval training in overweight sedentary adults.”