Spend less time working out with HIIT

High-intensity interval training (HIIT) is a specialized form of training that involves short intervals of maximum intensity exercise, followed by longer intervals of low- to moderate-intensity exercise. The key element of HIIT, that makes it different from other forms of interval training, is that its intervals involve maximum effort, not simply a higher heart rate. 

How HIIT works

The intense exercise interval may range from five seconds to eight minutes performed at 80 to 95 percent of your estimated max heart rate (the maximum number of times your heart will beat in a minute without overexerting yourself). The shorter the interval the less time you will have to get your heart rate up so the higher your intensity must be. During this interval of maximum effort, you're pushing your body into the anaerobic zone. Use the "talk-test" as your guide; it should be difficult to carry on a conversation. You can also have a VO2 max test done to identify your target heart rate zones.

The lower intensity exercise interval, or recovery interval, may last as long or longer as the intense interval and usually performed at 40 to 50 percent of your estimated maximum heart rate. This would be physical activity that felt very comfortable, in order to help you recover and prepare for your next intense interval. It should be easy to carry on a conversation during the recovery interval.

The workout continues with the alternating higher intensity and lower intensity exercise for a duration of 20-60 minutes. 

Why HIIT should be part of your workout routine

1. Enhance your current routine. HIIT isn't a new fitness routine you need to learn or buy new equipment for. It's actually something you can incorporate into your current preferred exercise: running, cycling, walking, swimming, elliptical training and even group fitness classes.
2. Burn more calories in less time. HIIT workouts provide similar fitness benefits as steady-state endurance workouts (running at the same pace for full workout), but in shorter periods of time. This is because HIIT workouts tend to burn more calories during and after the workout, about 6 to 15 percent more calories than traditional workouts.
3. Lose more fat. The effects of all those high-intensity intervals pushes your body into hyper-repair mode. That means your body burns more fat and calories in the 24 hours after a HIIT workout than you do after a steady-state endurance workout.
4. Keep your muscle mass. Steady-state endurance workouts seem to encourage muscle and fat loss, while HIIT allow you to preserve hard-earned muscles while ensuring most of the weight loss comes from fat stores. 
5. See quicker results. Just two weeks of HIIT improves your aerobic capacity as much as six to eight weeks of endurance training, according to a study by the American College of Sports Medicine.

Before you begin

If you've been living a rather sedentary lifestyle or had long periods of physical inactivity, jumping right into a HIIT routine is not a good idea. Prior to beginning HIIT training you should establish a foundational level of fitness (or base fitness level) that consists of aerobic and strength training. Medical clearance from a physician may be an appropriate safety measure for anyone with a history of smoking, hypertension, diabetes, abnormal cholesterol levels, coronary disease or obesity.

There are many different approaches to HIIT, each involving different numbers of high and low intensity intervals, different levels of intensity, different lengths of time for each interval and different numbers of training session per week. If you want to use HIIT for a particular sport or activity, you'll need to tailor your training to your specific needs. Learn more about how to get started with your own routine during the free webinar Exercise HIIT Training Basics.

Also keep in mind that HIIT workouts are more exhaustive then steady-state endurance workouts. So you'll need a longer recovery time between workouts. Maybe start with one HIIT training workout a week and as you feel ready for more challenge add a second HIIT workout.