Athletes are divided into those who love Cardio and who hate it, but even haters admit that this is an inevitable evil that burns fat, develops endurance and helps to look perfect.

Cardio improves the effectiveness of strength Training, improves mobilization of body fat and promotes fat burning. But the question of what cardio is better (low-intensity or high-intensity) is still controversial. Despite the huge popularity of low-intensity aerobics among professionals and amateurs, recent studies have shown that high-intensity interval cardio (HIIT) burns more calories. Well, let’s explain all the differences.

Mechanisms of Fat Burning in the Body

To lose weight during training, it is necessary to create favorable conditions for the release of fatty acids and their further combustion with the release of energy. Everything looks pretty easy and simple. you visit the gym, train your muscles, and it is in the bag! You spent a lot of energy, therefore, fat began to burn. But in reality, everything is not quite as we would like. Not always strength training can give us the fat-burning effect that we expect of it. And this is due precisely to the mechanism of fat burning.

In order to lose weight, the body needs oxygen, only in its presence fats can be oxidized.

Generally speaking, there are 2 types of energy that our body can use to perform some kind of physical work:

• “Fast” energy (anaerobic and aerobic glycolysis), which is produced due to reserves of ATP, creatine-phosphate, and glycogen. Aerobic glycolysis is the breakdown of glucose to carbon dioxide and water. It is a fast energy, but it can be used for a long time. Such a method of obtaining energy can only be used by well-trained athletes, whose oxidative capabilities are at a very high level. For ordinary people this way of obtaining energy is virtually not available.
• “Slow” energy (aerobic lipolysis), which is produced as a result of fat oxidation.

Some steroids like Winstrol and Trenbolone lead to activation of fat burning processes in the body.

Features of Low Intensity Cardio Workouts, Do’s & Dont’s

The essence. This is a cardio training in its classical sense, which activates the aerobic oxidation system.

Recommended heart rate. Low Intensity Cardio Workouts should be performed in the medium intensity range (heart rate should be 65-70% of the maximum) and from medium to long duration (20-60 min). The pace of execution does not change (the so-called steady state).

Effects. Used in bodybuilding, drowns fat, increases stamina and has other beneficial effects, described above.

Examples. Workouts on an elliptical machine with moderate intensity.

This is important. The most useful and most natural kind of cardio activity is … walking. The human body has been created for walking. Walking gives the same effects as classic cardio training for burning fat. At the same time, it has no disadvantages, such as a load on the joints, the risk of injury or overtraining. Therefore, if you want to maximize fat burning processes, walk more.

Do’s. You use this cardio as a warm-up before strength training, but the time of performing should be limited to ten minutes, not more. Longer sessions should be executed after resistance training.

Dont’s. Do not perform long low-intensity sessions before resistance workouts, as this can negatively affect the growth of muscle mass and strength.

Read our article on the best 30 minute cardio workouts at home and gym.

Features of High Intensity Cardio Workouts, Do’s & Dont’s

The essence. High-intensity interval training involves alternating short intense periods of exercises with moderate ones.

Recommended heart rate. The workout might look like this:

• 5 minutes warm-up – 50% of HR max;
• 3-5 intervals: 30 seconds – 70-85% of HR max, 60 seconds – 45-65% of HR max;
• 5 minutes cooldown – 50% of HR max.

Effects. HIIT provides powerful fat burning. If you train at home with your own weight, then you can alternate intense exercises like burpees, lunges, push-ups, jumps, sprints, with moderate exercises, like running in place, swinging your arms and legs. This principle is used  by Jillian Michaels, so her video courses are so popular and effective.

This is important. It is not recommended to do HIIT too often. You do not need to go to extremes and perform interval cardio every day, or even 2 times a day (some people do so). You should know that intense cardio gives a big load to the heart and joints. Also it exhausts nervous system. That’s why once or twice a week it will be enough to use the advantages of this type of training as much as possible while not driving your body in a state of overtraining.

Do’s. It is recommended to do HIIT workouts after strength workouts or on non-training days. “But I do not recommend doing HIIT after a hard day of legs or back, because you can not cope with the planned load,” expert Chrissy Kendall have said.

Dont’s. Do not perform too heavy exercises. According to  Kendall, “you should have a good level of general functional training and cardiorespiratory endurance, and there should be no damage to the joints or soft tissues”. There is a special HIIT variation for beginners: low impact HIIT. It implies 4 exercises 20 seconds on, 10 seconds rest, 4x through for each exercise (no equipment).

Read our article on best HIIT 20 and 30 minutes workout. You might also be interested in what steroid burns fat.

Low Intensity Vs. High Intensity Cardio Workouts: a Review

Each type of cardio workout has its advantages and disadvantages. There is a myth about the benefits of low-intensity cardio training: using a primitive scale on the treadmill, people piously believe that they intensively burn fat by walking. Strangely enough, this is not quite true: low-intensity training is not as effective as we would like (but do not underestimate walking, it is effective, however, you should walk a lot to achieve the desired effect).

The fact is that when the training in anaerobic regime ends, the need for energy, accordingly, immediately fades to nothing. As a result, your fat stops burning. With interval cardio training, the need for additional energy will last longer: from a few hours to a day.

One of potential steady state cardio disadvantages implies burning muscles along with fat due to prolonged trainings. This is because cardio is a process that is energy intensive, it requires a lot of efforts. When the body do not have other resources, it starts to burn amino acids in muscle tissues (by the way, you can use BCAA to prevent that effect). Of course, weight decreases, but not in the way that you would like. This is a very, very fast way to skinny fat. But when it comes to active recovery, nothing compares to a low-intensity cardio session that increases the flow of blood to the muscles, helps to remove the by-products of metabolism from tissues and speeds up regenerative processes.

High intensity cardio workouts develop muscular system, bring the body in tone. A specific advantage is in that HIIT powerfully trains and develops cardiovascular system.

The disadvantage of HIIT is that this workout is not for everyone. If you have problems with the heart or blood vessels, always consult your doctor before starting HIITs. Despite the huge popularity of low-intensity aerobics, high-intensity workouts show a greater efficiency of fat burning (so we can say with certainty that steady state cardio has a lower efficiency than HIIT). Unfortunately, the high-intensity method is suitable only for trained and healthy people.

Beginners will take a lot of benefits from traditional cardio. People with cardiovascular diseases should focus on increasing aerobic endurance, improving heart function and neatly entering the training regimen, which also can be done with low-intensity cardio.