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How does high-intensity interval training burn fat

How does high-intensity interval training burn fat?

High-intensity interval training (HIIT) uses short bursts of vigorous exercise alternating with low-intensity recovery times. HIIT helps burn more calories more effectively than traditional exercise thanks to its effects on your body’s metabolism and metabolic rate as well as muscle mass.

Aside from this, HIIT training also improves your aerobic capacity, heart health, blood pressure, and so much more.

You can perform high-intensity exercise anywhere you like using your bodyweight or equipment like jumping rope, stationary bike, rowing machine, and more. 

In this article, we will answer the most common question of ‘how does high-intensity interval training burn fat’ and how intense bursts of exercise can lead to significant fat loss and its health benefits. If you’re interested in learning about how high-intensity interval training burns fat, then stay until the end.

High intensity interval training benefits

What is HIIT?

HIIT workouts combine short bursts of intense exercise with periods of rest or less intense exercise. The exercises in fitness studios and on the internet usually combine aerobic and resistance training. Whereas, some workouts combine weight training, but it’s more common to use your body weight.

Each HIIT session combines a number of different exercises or the same exercise for a short period of time followed by a brief break. The combination of exercises and the limited time period you’re supposed to perform them for are designed to bring your heart rate to the maximum effort.

Whereas the exercise breaks should be set for fixed periods between each period of exercise. These can include either less intense exercises or an actual break where you either walk around at your own pace or standstill. If you wish to burn more calories, then be sure to perform some less intense activity.

All that intense exertion over 15-25 minutes can help you burn more calories and burn fat.

How does high-intensity interval training burn fat?

HIIT workouts help you burn fat in a number of ways. This type of exercise is not just incredible for improving your aerobic fitness or burning more calories, but it supports fat loss by triggering human growth hormone and speeding up your body’s metabolism and metabolic rate.

If you are the type of person who faces time and space constraints or has a busy schedule then this type of HIIT workout can be more suitable for you and your lifestyle.

These exercises run for a short period of time followed by a low-intensity activity like brisk walking or another steady pace run. However, although these last for a short period, they require all-out effort.

So, how does high-intensity interval training (HIIT) burn fat?

Increase in metabolism

Your body’s metabolism refers to all the biological and physiological processes that occur in the body. Whether you have just consumed foods and it’s getting digested, or you’re feeling stressed so the body secretes certain hormones – all of these actions require a number of calories every day. The number of calories your body is able to burn naturally depends on your health.

A healthy metabolic system may help you efficiently burn more calories and remove toxins from the body. This means that you’ll be burning calories after your HIIT workout. This is known as the HIIT afterburn.

One study has shown incredible results of a 60% increase in metabolism and fat burning after 6-weeks of HIIT training [1].

HIIT workout improves insulin sensitivity

Another way that HIIT helps you burn more fat is by improving sensitivity to insulin. Insulin is a hormone that is released in response to sugar. It is responsible for regulating blood sugar levels by pushing any excess sugars into tissues like muscles.

If your sugar levels stay elevated for prolonged periods of time then these tissues can become insensitive. This means that they may stop taking in the sugars. As a result, insulin will signal to your body to store these sugars as fat instead.

A 2018 study reported that eight weeks of HIIT cardio and endurance training combined with strength training significantly increased fat burning [2].

Effect of HIIT workouts on hormones

Another way that HIIT workout helps you lose weight is by increasing certain hormones. HIIT training increases epinephrine and norepinephrine levels. These two hormones control lipolysis which refers to the breakdown of body fat stores. These high-intensity intervals not only help you build lean muscle mass and improve your resting metabolic rate but also help your body become more efficient at burning fat [3].


In summary, HIIT workouts are one of the most efficient ways of burning more weight through intense bursts of aerobic exercise followed by steady-state cardio. If you are looking to lose fat and especially your belly fat then this is a great option.

These high-intensity intervals help you lose fat and weight by burning calories, changing your resting metabolic rate, increasing insulin sensitivity in your tissues, and releasing a number of hormones.


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[1] Perry, C., Heigenhauser, G., Bonen, A. and Spriet, L., 2008. High-intensity aerobic interval training increases fat and carbohydrate metabolic capacities in human skeletal muscle. [Accessed 28 September 2021].

[2] de Matos, M., Vieira, D., Pinhal, K., Lopes, J., Dias-Peixoto, M., Pauli, J., Magalhães, F., Little, J., Rocha-Vieira, E. and Amorim, F., 2018. High-Intensity Interval Training Improves Markers of Oxidative Metabolism in Skeletal Muscle of Individuals With Obesity and Insulin Resistance.  [Accessed 28 September 2021].

[3] Alansare, A., Alford, K., Lee, S., Church, T. and Jung, H., 2018. The Effects of High-Intensity Interval Training vs. Moderate-Intensity Continuous Training on Heart Rate Variability in Physically Inactive Adults. [Accessed 28 September 2021].

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