Cardio is a staple in any bodybuilder’s or lifter’s regimen, whether your goal is to reduce body fat levels or enhance the advantages of being cardiovascularly fit. If your goal is to turn up calorie burning and lose pounds faster, the answer may be high-intensity interval training (HIIT).
HIIT involves short intervals of high-intensity work—training near 90% maximum heart rate (MHR)—followed by intervals of slower-paced active recovery. To keep your body guessing (and the scale moving), you have to either add more cardio or increase the intensity. Most people don’t have the time to devote to daily cardio workouts. Adding a few hard HIIT sessions will get the job done and save you time.
Research confirms the shorter-duration HIIT method is superior to steady-state cardio for losing fat. In a landmark 1994 study published in the journal Metabolism, researchers had one group follow a 15-week HIIT program and another perform only steady-state cardio for 20 weeks. The data revealed that the steady-state group burned 15,000 more calories but the HIIT group lost significantly more body fat.
Another study conducted at the University of New South Wales (Australia) reported that a group of women who took part in a 20-minute HIIT program of eight-second sprints followed by 12 seconds of rest lost six times more body fat than a group that did steady-state cardio for 40 minutes at 60% MHR. And that’s not HIIT’s only fat-fighting benefit. The increase in intensity boosts the metabolism and keeps it higher longer after your workout is over. This is known as EPOC, or the afterburn effect, which in part helps fuel the repair of exercise-induced damage.
Research on subjects using either low-intensity protocols or the HIIT method found that the HIIT group burned an average 10% more calories in the 24 hours following exercise than the low-intensity groups, even though the total calories burned during each workout were the same. So if you train intensely enough, you’ll burn calories just sitting on the couch afterward.