If I told you that there was a way to burn more calories, lose more fat, and improve your cardiovascular fitness level while spending less time doing cardio, you’d probably reach for your phone to report me to the consumer fraud hotline, right?
Well, this is one of those rare times when your natural it’s-too-good-to-be-true reaction could be mistaken. If you want to take your fitness and fat loss to the next level—without spending more time in the gym—then high-intensity interval training (also known as HIIT) could be exactly what you're looking for.
Before getting into the details, notice that I didn’t say HIIT would be easier, just that it would take less of your time. In fact, the HIIT approach to cardio exercise is very physically demanding and isn’t for everyone. If you have any cardiovascular problems or other health concerns that limit your ability to exercise at very intense levels, or if you are relatively new to aerobic exercise or not already in good shape, HIIT is not for you—at least for now. If you have any doubts or concerns about whether it might be safe for you, check in with your medical professional before trying HIIT.
What Is High-Intensity Interval Training and How It Works
HIIT is a specialized form of interval training that involves short intervals of maximum intensity exercise separated by longer intervals of low to moderate intensity exercise. Because it involves briefly pushing yourself beyond the upper end of your aerobic exercise zone, it offers you several advantages that traditional steady-state exercise (where you keep your heart rate within your aerobic zone) can’t provide:
The key element of HIIT that makes it different from other forms of interval training is that the high intensity intervals involve maximum effort, not simply a higher heart rate. There are many different approaches to HIIT, each involving different numbers of high and low intensity intervals, different levels of intensity during the low intensity intervals, different lengths of time for each interval, and different numbers of training sessions per week. If you want to use HIIT to improve performance for a particular sport or activity, you’ll need to tailor your training program to the specific needs and demands of your activity.
HIIT trains and conditions both your anaerobic and aerobic energy systems. You train your anaerobic system with brief, all-out efforts, like when you have to push to make it up a hill, sprint the last few hundred yards of a distance race, or run and hide from your spouse when they won't stop nagging you about the dishes.
HIIT increases the amount of calories you burn during your exercise session and afterward because it increases the length of time it takes your body to recover from each exercise session.
HIIT causes metabolic adaptations that enable you to use more fat as fuel under a variety of conditions. This will improve your athletic endurance as well as your fat-burning potential.
HIIT appears to limit muscle loss that can occur with weight loss, in comparison to traditional steady-state cardio exercise of longer duration.
To get the benefits HIIT, you need to push yourself past the upper end of your aerobic zone and allow your body to replenish your anaerobic energy system during the recovery intervals.