Experts said High Intensity Interval Training (HIIT) is more effective the harder you push yourself.
This type of exercise is characterized by short bursts of high intensity activity followed by recovery periods, Reuters reported. HIIT can burn calories and build muscle in as little as 20 minutes per day, but fitness trainers say the trick to achieving the best results is to find the perfect level of intensity outside of one's "comfort zone."
Sean Bartram, author of the book "High Intensity Interval Training for Women," told Reuters the best way to find that "sweet spot" is to imagine being chased by a rabid dog during the high intensity part of the workout.
"It's just below that," he said. "To gain maximum benefits you have to push your body to a place that's almost uncomfortable."
The short bursts of high-intensity activity can be anything from sprinting to push-ups with intervals of slower movements in between.
"You could alternate 30 seconds of sprinting with 30 seconds of walking, or you could engage in a series of bodyweight exercises, such as push-ups, doing each for 30 seconds with 10 seconds of rest in between," Bartram said.
Michele Olson, a professor of exercise science at Auburn University at Montgomery, Ala., pointed out that physical activity cannot be classified as high intensity unless one elevates the heart rate to about 90 percent of its maximum or higher.
"Many people think they are engaging in HIIT, but they are really doing traditional interval training, where the heart rate is around 75 to 85 percent of max," she told Reuters.
Performing only about 20 minutes of HIIT activity can be equivalent to doing 35 to 40 minutes of moderate cardio, allowing people to significantly cut down on their exercise time while reaping the same benefits. Researchers have also suggested HIIT can help one lose abdominal fat more effectively.
"There is research showing that you can cut your exercise time nearly in half," Olson said.
