Workout trends seem to come and go in cycles, just like fashion. High-intensity interval training, or HIIT, is a prime example. HIIT programs combine short bursts of high-intensity exercise with periods of low-intensity activity that allow for partial recovery. This approach to fitness dates back decades.
While its cycle back may seem like just another fitness fad, the program actually offers a host of science-backed benefits.
A great way to ease into HIIT is to focus on cardiovascular activities, such as cycling, rowing and running. To turn running into a HIIT workout, you might sprint for two minutes and walk for four minutes. You can also combine HIIT with cross-training. For example, perform a set of squats and push-ups, and follow up with four or five minutes of dynamic stretching or active recovery.
Here are five HIIT perks:
- Enhanced aerobic fitness: Compared with traditional endurance training, HIIT has a greater impact on your aerobic fitness. Exercise increases your body’s demand for oxygen and thus trains it to become more efficient both during and after a workout. Short intervals of high-intensity exercise require a tremendous amount of oxygen, both during activity and during recovery. Over time, you’ll increase your body’s VO2 max, the amount of oxygen you can use per kilogram of body weight. Stick with it and you’ll notice you need less recovery time between high-intensity intervals.
- Increased fat burning: Even though HIIT sessions tend to be shorter than conventional workouts, they often burn the same number of calories. HIIT also promotes fat loss by increasing your metabolic rate for hours after you’re done exercising.
- Customized workouts: Most people start with a two-to-one ratio (such as 10 seconds of high-intensity activity followed by 20 seconds of low-intensity recovery). But seasoned athletes may choose to turn the ratio upside down, sprinting for 20 seconds and recovering for 10. The end result: You can tailor the workout to meet your specific goals.
- Fast impact: With HIIT, you get maximum benefit with minimal time. A typical HIIT session lasts between 10 and 30 minutes.
- Versatility: HIIT allows you to vary your workouts according to your goals. If you’re trying to build strength and tone, you can choose a series of activities that achieve that end. Start with 15 minutes of sit-ups, squats and sprints, then jog for your recovery. Want to boost your endurance? Intersperse sprints with easy jogging.
The Anatomy of a Solid HIIT Routine
A typical HIIT workout begins with a gentle three- to five-minute warmup. Depending on the high-intensity activity you choose, you might do four to six sets of one-minute bursts followed by a two-minute active recovery. Finish with a three- to five-minute cooldown. Add it all together and you have an 18- to 28-minute workout.
Here are a few simple examples of HIIT workouts:
- On a stationary bike: After a short warmup, pedal rapidly with high resistance for 30 seconds followed by two to four minutes of cycling at a slow, easy pace with minimal resistance. Repeat the pattern for 15 to 20 minutes, then cool down for five minutes.
- Running: Start with a brisk walk and slow jog for a few minutes then sprint as fast as you can for 30 seconds followed by a slow jog for one to two minutes. Repeat the pattern for 10 to 20 minutes and cool down for five minutes.
- Cross-training: Start with a three-minute warmup focusing on the legs. Perform squats or squat jumps as quickly as possible for one minute. Then walk for two minutes. Repeat the pattern for up to 20 minutes and do a five-minute cool down.
HIIT Cautionary Notes
Just with any activity, HIIT training isn’t risk-free. Certain activities and repetitive movements can increase your odds of injury. This is especially true if you’re doing body weight exercises.
No matter which type of HIIT workout you choose, it’s important to start slow and work your way up, especially if you’re new to training. And always make sure you’re cleared by a physician to engage in high-intensity activity.
Low-impact HIIT activities, such as swimming, cycling and rowing, may be appropriate if you’re elderly, sedentary or have chronic health conditions. But if you have a known injury or a condition that affects your heart or lungs, HIIT training may not be appropriate for you.