High-intensity interval training, or HIIT, will be the top fitness trend for 2014, according to the American College of Sports Medicine. HIIT’s popularity is in part because it burns more calories than steady-state exercise. A study published in the April 2008 issue of the "International Journal of Obesity" confirmed that interval training burns more fat than steady-state exercise such as jogging. Some of that fat is burned long after you finish your workout in the form of a so-called afterburn. If you’re looking to get rid of fat, exercises that produce an afterburn may be a good option for you.
Intervals: Beyond Basic Cardio
Interval training is an advanced form of cardio training that takes you beyond your comfort zone. Rather than jogging or cycling at a moderate speed for the entirety of your workout, interval training, as the name suggests, involves breaking down your workout into intervals. You perform short bouts of high-intensity exercise such as sprinting, followed by longer bouts of active recovery such as walking. The high-intensity exercise is meant to be as intense as you can handle and the active recovery allows you to recover and prepare yourself for the next interval.
You can do interval training in many ways. Your intense intervals can be as short as eight to 10 seconds or as long as five minutes, while your recovery time is typically twice as long as your intense interval. The American Council on Exercise suggests HIIT that consists of four high-intensity intervals, each one minute in length, followed by four recovery periods, each two minutes in length. It also suggests that when you are doing your high-intensity exercise, you work at an exertion level of at least seven on a scale of one to 10, with 10 being the hardest workout you can manage.
After any exercise, your body needs to expend some calories to return to its pre-exercise state. These extra calories are called the afterburn or excess post-exercise oxygen consumption (EPOC). The length of your afterburn and the number of calories you burn during this time depends on the intensity of your exercise. Workouts involving high-intensity training such as HIIT can cause your body to have an afterburn for up to 48 hours after you’ve finished exercising. While you will have the afterburn effect during intense steady-state exercises such as a fairly fast run, research analyzed at the University of New Mexico concluded that afterburn is greater after intermittent exercise or interval training.
HIIT is not for everyone. High-intensity exercise is often also high-impact and this can put you at risk of musculoskeletal injury. The high intensity may also be risky if you have previous cardiovascular concerns. Speak to your doctor if you are a new exerciser or have health concerns before starting this type of exercise. Always begin and end your workout with a warm-up and cool-down. Leave at least 48 hours between interval training sessions to avoid overtraining that can lead to injuries.