Interval training stands out among all the other types of physical exercises. Initially, professional athletes practiced it as a preparation for competitive exercises. Today, people use it to get rid of excess weight and to get in shape so they can look beautiful and fit.

Interval or HIIT training (high-intensity interval training) is a sequence of physical exercises performed with different levels of intensity:

1. High. 80-90% of the body’s resources are involved.
2. Low. 40-60% of resources are involved.

A high degree of intensity is aimed at ensuring that the body uses up the maximum amount of energy stored in the muscles. The low-efficiency interval has the opposite function. It enables you to restore strength due to the quantitative change in fats and carbohydrates.

The principle of HIIT training is the periodic repetition of heavy loads. Due to this phenomenon, it’s also called cyclic. The effectiveness of interval training directly depends on how correctly the number of cycles is pre-determined. Within one training session there should be at least 3 but not more than 8 intensive stages. The person or their coach decides on the exact number, guided by the principle of extreme fatigue.

Interval training has multiple advantages. It differs from other types of physical activities by allowing you to achieve the following results:

1. Helps to boost the speed of your metabolic processes. When burned, glycogen stimulates the synthesis of hormonal substances. Metabolism accelerates.
2. Gets rid of fat deposits under the skin. The intensive stages of training lead to microscopic damage to muscle fibers. When the low-efficiency stage begins, they’re restored due to their fat cells.

Thanks to HIIT training, it becomes possible to build muscle mass and achieve a significant increase in overall volume.

Interval-type physical training is the best option for those who want to reduce their body weight in a short amount of time. The correct ratio of intervals of different intensities helps to achieve a noticeably positive result. The high-efficiency cycle should last at least 60 minutes. The low-efficiency cycle should last at least 90 minutes. Keep in mind that in order to withstand such loads, a certain physical fitness level is required.

The term “intensive training” refers to different types of physical activities:

1. Tabata protocol. The ratio of high-intensity and low-efficiency cycles is 2:1 (20 and 10 seconds, respectively). The total duration of the set is 8 minutes. During this time, you should perform 16 cycles of intensive exercises.
2. Waldemar Gershler’s methodology. A certain distance is covered in the shortest possible time. Then, the time period decreases by 3 seconds and the same distance is covered once again. The rest between your sets is 2 minutes. The exercises are repeated until the heart rate normalization time becomes less than 2 minutes. Training according to this technique can last no more than half an hour. Its main goal is to boost speed endurance.
3. Fit mix. It’s a combination of various fitness exercises (stretching, classical anaerobic strength training and breathing exercises). Its benefits are manifested in the fact that the cardio system becomes more resilient, the muscles throughout the body become toned and the speed at which metabolic processes increase.

Another variant of HIIT training is called fartlek. Its distinctive feature is the participation of at least two people training together. They compete in a sprint over a distance of four-hundred-meters. The route can take place on a flat surface or on a slope. The mandatory component of the fartlek is the warm-up stage, which consists of joint gymnastics and jogging.

Interval training is classified as difficult and requires a lot of effort. Beginners who lack experience have a high risk of making mistakes, fraught with serious negative consequences to their bodies. To minimize these risks and ensure a high efficiency in training sessions, it’s recommended to adhere to several rules:

1. Keep a training diary. It will help to systematize the data at the end of each session as well as track specific and general progress. It will allow you to choose the optimal sports mode.
2. Stick to a gradual progression of physical activity. The body isn’t able to quickly adapt to changing environmental factors. Therefore, the increase in intensity and duration of loads from one training session to another should be no more than 10%.
3. Avoid overdoing your workouts. 2-3 interval classes per week are considered optimal. If you train more, the muscles won’t have enough time to recover after your intense training.
4. Don’t neglect the warm-up. It will prepare your body for exertion and reduce the delayed onset muscle soreness after exercise.
5. Select the program for your training sessions. It should be compiled individually in strict accordance with the goal that is planned to be achieved.

An important indicator characterizing various types of HIIT training is your heart rate. Its maximum value is defined as the difference between the number 220 and the age of the trainee. Different types of exercises have different maximum allowable heart rates. You should remember this.

During interval training, the body experiences significant loads. Not everyone is able to endure them without harming their health. Be aware that people who have problems with the following should give up HIIT training:

1. Vascular and heart diseases in a chronic form
2. Disorders of the joint structure in a degenerative nature
3. Intermediate or critical stages of the curvature of the spine

If a person lacks special contraindications to interval physical exercises but they feel exhausted, it’s recommended to refrain from performing such exercises until they feel better.