HIIT - Benefits and contraindications of high-intensity interval training

HIIT - Benefits and contraindications of high-intensity interval training

HIIT - Benefits and contraindications of high-intensity interval training
HIIT - Benefits and contraindications of high-intensity interval training

HIIT or high-intensity interval training is a method that has gained popularity in recent years.

Studies confirm that it has significant health benefits. However, it may be contraindicated for a small number of people.

This article describes in detail what HIIT consists of, its benefits and contraindications, supported by scientific evidence.

What is HIIT?

The abbreviation HIIT stands for "  High-Intensity Interval Training  " in English, which translates as high-intensity interval training. HIIT is a method that allows you to improve muscle strength and endurance.

In the HIIT routine, high-intensity exercise alternates with low-intensity exercise. The contraindications and benefits of HIIT are described below to say yes or no to this method of training.

The HIIT training program consists of alternating between about 20 seconds of high-intensity exercise, 20 seconds of cardio, and rest for the next 10.

The idea is to combine exercises that increase the heart rate (for example, running at maximum speed) with strength exercises in   a functional mode . The cycle is repeated about 4 times  (1)  .

Advantages of HIIT


HIIT workouts are ideal for those who carry out weight loss processes. Its benefits are to reduce body mass index, speed up metabolism and reduce body fat percentage. This is a method proposed by trainers for overweight people. The advantages of HIIT are:

1. Increase respiratory capacity

Studies confirm an increase in aerobic endurance and maximal respiratory capacity (  VO2 max  ) when performing HIIT  (2) (4)  . Some authors confirm that with only 2 months of adaptation, significant changes in the ability to transport and absorb the amount of oxygen in the blood are generated.

2. It can speed up the basic metabolism

This is one of the most controversial advantages of HIIT. Some authors claim that HIIT accelerates the  basic metabolism  . (5) However, studies still need to be carried out to confirm this. One of the benefits of HIIT has been shown to be the normalization of glucose metabolism, ideal for the prevention of chronic diseases such as type 2 diabetes.

3. Increase testosterone levels

High-intensity interval training  increases testosterone  . This is explained by the intensity. By working hard, the body releases more sex hormones to counteract the effects of muscle stress.

4. Eliminate body fat

The main benefit of HIIT is the ease with which a person can  shed body fat  . This method of training is specially designed for those who have problems with overweight and obesity. (4)

5. Short duration and easy adaptation

The last of the advantages of HIIT is its short duration. If you are one of those who always run to get to the office and go to the gym. Or try to study and practice at the same time; the high intensity interval system is ideal for you. In 30 minutes you will be ready, not to mention that this is one of the methods with the best adaptive potential and does not require much equipment. (4)

HIIT contraindications

HIIT contraindications

High-intensity interval training is not for everyone. If you haven't exercised in a while, it's not a good idea to start by returning to HIIT. Below are the contraindications of HIIT:

1. People with joint or tendon problems or injuries

If you have suffered a knee or shoulder injury, you should look for other high-intensity exercise options that do not involve a blow to the joints. High-intensity loads can be dangerous when re-injuring joints and tendons. On the other hand, the use of supplements such as hydrolyzed collagen, glucosamine and chondritin has been shown to be effective in preventing joint wear.

2. People with respiratory problems or asthma

You need to have a good aerobic base to start high-intensity interval training. People with asthma or respiratory problems should not engage in HIIT unless they have tried another type of exercise.

3. Take pressure medication

One of the contraindications to HIIT is that this type of training is not recommended for people other than those taking blood pressure medications. High-intensity work can cause severe heart events.

4. Pregnant women

Pregnant women should not have HIIT. Abrupt movements, jumping and rapid heartbeat can create problems for the fetus. Although this method of training is effective for losing extra pounds after pregnancy, other types of lower-intensity exercise, such as Pilates, are recommended during treatment.

5. People with uncontrolled diabetes

One of the contraindications to HIIT is for those with uncontrolled diabetes. Special care must be taken when carrying out activities of this type. Calorie expenditure is usually high and hypoglycaemic events may occur.

6. Injuries to the knee or shoulder

If you have suffered a knee or shoulder injury, you should look for other high-intensity exercise options that do not involve a blow to the joints. High-intensity exercise can be dangerous in reproducing joint and tendon disorders.

Does HIIT work for weight loss?

When working at low intensity, slow muscle fibers are the ones that work; This type of fiber uses fat deposits as a source of energy. When working with high-intensity loads, these are fast-twitch muscle fibers, the type of fibers that use muscle glycogen for energy.

In HIIT training, both intensities alternate, allowing the development of both types of muscle fibers. This fact and the improvement of the cardiovascular system are the main advantages of HIIT.

This training system is used with excellent results to reduce obesity in children and people with high levels of sedentary lifestyle. (4)

Metabolism and HIIT

In heavy training, the difference between intensity and load allows the body to make better use of fatty acids as an energy source. For this reason, some authors claim that HIIT is able to speed up metabolism.

The use of slow muscle fibers is not found in the traditional fitness routine, which leads to the need to supplement it with  aerobic exercise  . HIIT workouts focus on the number of repetitions and allow you to work on   myofibrillar muscle hypertrophy .

HIIT startup tips

When doing high-intensity interval training, precautions should be taken so that you can complete the sessions without problems. Here are 5 tips to follow when starting HIIT:

1. Do not combine it with thermogenics

In  thermogenic  as caffeine is not recommended for intense interval training. These substances increase blood pressure and heart rate, which can cause damage to health.

2. Drink homemade isotonic drinks

When doing HIIT, water loss due to sweating is usually excessive. Of  sports drinks  can help a person not to become dehydrated after exercise.

3. Do not go to the sauna after a workout

Going to the  sauna after a workout  can cause a drop in blood pressure and even fainting. High temperatures can have negative effects on the cardiovascular system. If you choose a method of muscle recovery, we recommend a  contrast shower  or  myofascial release  .

4. Do not combine it with the ketogenic diet

If you are on a  keto diet  or another low-carb diet  ,  do not combine it with high-intensity interval training. Performing this type of exercise with very low glucose levels can lead to loss of consciousness.

5. Drink more water during the day

When doing HIIT, you are likely to sweat in bulk. It is important to know that the amount of water you need to drink during the day increases by at least 500 mL when doing HIIT. If the cost of water is not compensated by sweat, mild symptoms such as dry skin and severe symptoms may occur; such as renal disorders.


  • Interval training with high intensity or HIIT consists of alternating exercises with maximum intensity with low intensity or aerobic exercises. The rest between the sets is minimal.
  • This method of training is one of the best  workouts for removing body fat  .
  • Doing HIIT burns a lot of calories. However, the theory that it is able to speed up metabolism has not yet been proven by experts.
  • High-intensity interval training is dangerous for beginners or people who are not used to exercising regularly.
  • Contraindications to HIIT are: people taking pressure medications, knee injuries and pregnant women.
  • HIIT procedures are similar to other methods such as  circuit training  ,  calisthenics  and  tabata  .


  1. High Intensity Training,  Source
  2. Ten Ways to Get More Out of Your Workout,  Source
  3. How one-minute intervals can improve your health  source
  4. HIIT, practical applications. source
  5. HIIT, benefits and contraindications. source