What Is High-Intensity Interval Training?
HIIT involves short bursts of intense exercise alternated with low-intensity recovery periods. Interestingly, it is perhaps the most time-efficient way to exercise.
Typically, a HIIT workout will range from 10 to 30 minutes in duration.
Despite how short the workout is, it can produce health benefits similar to twice as much moderate-intensity exercise.
For example, a HIIT workout using a stationary exercise bike could consist of 30 seconds of running on the spot as fast as possible followed by several minutes of slow, easy walking round the room. This would be considered one "round" or "repetition" of HIIT, and you would typically complete 4 to 6 repetitions in one workout.
The specific amount of time you exercise and recover will vary based on the activity you choose and how intensely you are exercising.
Regardless of how it is implemented, high-intensity intervals should involve short periods of vigorous exercise that make your heart rate speed up.
Not only does HIIT provide the benefits of longer-duration exercise in a much shorter amount of time — it may also provide some unique health benefits
1. HIIT Can Burn a Lot of Calories in a Short Amount of Time
You can burn calories quickly using HIIT
One study compared the calories burned during 30 minutes each of HIIT, weight training, running and biking.
The researchers found that HIIT burned 25–30% more calories than the other forms of exercise,
In this study, a HIIT repetition consisted of 20 seconds of maximal effort, followed by 40 seconds of rest.
This means that the participants were actually only exercising for 1/3 of the time that the running and biking groups were.
Although each workout session was 30 minutes long in this study, it is common for HIIT workouts to be much shorter than traditional exercise sessions.
This is because HIIT allows you to burn about the same amount of calories, but spend less time exercising.
So HIIT may help you burn more calories than traditional exercise, or burn the same amount of calories in a shorter amount of time.
2. Your Metabolic Rate Is Higher for Hours after Exercise
HIIT helps you burn calories after you are done exercising.
Several studies have demonstrated HIIT's impressive ability to increase your metabolic rate for hours after exercise.
HIIT was also found to shift the body's metabolism toward using fat for energy
So due to the intensity of the workout, HIIT can raise your metabolism for hours after exercise. This results in additional calories being burned even after you have finished exercising.
3. It Can Help You Lose Fat
HIIT can help you lose fat.
Additionally, one study found that people performing HIIT three times per week for 20 minutes per session lost 4.4 pounds, or 2 kgs, of body fat in 12 weeks approx.
Perhaps more important was the 17% reduction in visceral fat, the fat surrounding your internal organs.
However, like other forms of exercise, HIIT may be most effective for fat loss in those who are overweight or obese
So High-intensity intervals can produce fat loss, even with a much smaller time commitment. It can also reduce unhealthy visceral fat.
4. You Gain Muscle Using HIIT
HIIT could help increase muscle mass.
The gain in muscle mass is primarily in the muscles being used the most, often the trunk and legs
So you may gain some muscle by starting HIIT
5. HIIT Can Improve Oxygen Consumption
Oxygen consumption refers to your muscles' ability to use oxygen,
It appears that HIIT can produce the same benefits in a shorter amount of time as traditional endurance training
One study found that five weeks of HIIT workouts performed four days per week for 20 minutes each session improved oxygen consumption by 9%
So High-intensity interval training can improve oxygen consumption as much as traditional endurance training, even if you only exercise about half as long.
6. It Can Reduce Heart Rate and Blood Pressure
HIIT has important health benefits, as well.
A large amount of research indicates that it can reduce heart rate and blood pressure in overweight and obese individuals, who often have high blood pressure.
One study found that eight weeks of HIIT decreased blood pressure as much as traditional continuous endurance training in adults with high blood pressure
So HIIT can reduce blood pressure and heart rate, primarily in overweight or obese individuals with high blood pressure.
7. Blood Sugar Can Be Reduced by HIIT
Blood sugar can be reduced by HIIT programs
A summary of 50 different studies found that not only does HIIT reduce blood sugar, but it also improves insulin resistance more than traditional continuous exercise
High-intensity exercise is particularly beneficial for those at risk for type 2 diabetes.
In fact, some experiments specifically in individuals with type 2 diabetes have demonstrated the effectiveness of HIIT for improving blood sugar
So High-intensity interval training is beneficial for those needing to reduce blood sugar and insulin resistance. These improvements have been seen in both healthy and diabetic individuals.
How to Get Started With HIIT
There are many ways to add high-intensity intervals to your exercise routine, so it isn't hard to get started.
To begin, you just need to choose your activity (running, biking, jumping, etc.).
Then, you can experiment with different durations of exercise and recovery, or how long you are performing intense exercise and how long you are recovering.
The Bottom Line
· High-intensity interval training is a very efficient way to exercise, and may help you burn more calories than you would with other forms of exercise.
· Some of the calories burned from high-intensity intervals come from a higher metabolism, which lasts for hours after exercise.
· Overall, HIIT produces many of the same health benefits as other forms of exercise in a shorter amount of time.
· These benefits include lower body fat, heart rate and blood pressure. HIIT may also help lower blood sugar and improve insulin sensitivity.
· So, if you are short on time and want to get active, consider trying high-intensity interval training.