HIIT is no doubt a great way to melt off those body fat. The workout aims at quick fat burning and the ultimate reduction of fat cells that store fat reserves. But before moving on to the mechanism of fat burning by high intensity workouts or any other methods, you need to understand the mechanism of fat storage in the body.
When you consume food, some of it is used as glucose for energy expenditure. The extra food is stored in the form of glycogen in the liver. This is the reserve food that is used once the glucose levels in the body become low.
Fats and triglycerides are also used by the body for energy and fats provide the largest amount of energy. Extra fat is stored in cells called adipocytes that are abundant in the flank, thighs and the abdomen region. The aim of any exercise is to signal the body burn these reserve carbs and fats.
But before this happens, the body has to exhaust the glucose and triglycerides that are already present in the body. Once those are used up for fuel, the body starts to use the reserve glycogen and fats.
How does HIIT work for fat loss?
Metabolism refers to all the processes that take place in the body. These can be of two types.
These are the reactions in which new products are synthesized using the reactants that are present in the body. These things are often extracted from the food we take in, such as proteins and carbs.
These reactions are the ones in which something is broken down into smaller particles or for excretion from the body. These reactions may be fat oxidation in which fats are burnt into their respective components. Other than that, catabolic reactions include carb burning and breaking down of larger nutrients into their monomers use these building blocks for making something new.
Both these reactions take place side by side and both need energy to function. This energy comes from burning carbs that are already present in the body.
When a person performs a high intensity workout, their metabolic rate is enhanced. Due to this acceleration of the metabolic rate, reactions in the body also take place at a faster rate. Since more reactions occur and at a faster rate, the fat reserves in the body also start being used up for energy.
With HIIT your metabolism remains in action even in the resting stage; HIIT is much better at enhancing resting metabolism than aerobic exercises. It keeps the resting metabolism going on at a significant rate for 24 hours after the workout, which is just in time for the next workout. Therefore, it keeps the body burning fat during the whole day, even when at rest.
HIIT And Fat Oxidation
Fat oxidation is the process in which fats are broken down into triglycerides. In cells, oxidation of fat occurs as a result of which triglycerides are produced. These are used for energy provision or they can be stored in the adipose tissue. Since HIIT induces fat oxidation, it ensures that body fat is being broken down instead of getting stored up.
The liver is the only organ in the body that can dispose of cholesterol. When fat reserves build up on the liver, the liver cannot function properly due to pressure exerted on it by the fat concentration. As a result of HIIT, the fat reserves melt which causes the liver to function properly for disposing off cholesterol.
Increase In Growth Hormone Levels
HIIT has also shown to increase growth hormone levels. This hormone is also involved in the fat burning mechanism in the body along with enhancing metabolism. In the presence of this hormone, the metabolic rate of the body improves and the efficiency of metabolism is also enhanced significantly.
During high intensity workouts, a chemical is produced in the body called catecholamine. This chemical facilitates fat loss since it mobilizes the stored fat. The fat reserves keep increasing in the body until the previous ones are burnt.
In the presence of this chemical, the fat that is stored in the adipose tissue is mobilized so that it can be used as fuel for energy. The primary source for fuel in the body is carbohydrates so the body has to produce some kind of chemical to make the fats available for fuel.