The concepts of physical fitness are gradually changing, as the common saying "no gain without effort" no longer always applies when it comes to burning fat and improving health.
Instead of relying on high-intensity, maximum-energy exercises, a growing number of experts are calling for a focus on what are known as "Zone 2" exercises, which are moderate-intensity exercises such as brisk walking, light jogging, or cycling at a pace that allows you to talk while performing.
To understand this concept, experts divide heart rate into five zones, ranging from very light exertion to maximum intensity. The "second zone" lies in the middle of this range, at approximately 60% to 70% of the maximum heart rate, which, according to experts, is the optimal level for burning fat and improving physical performance.
The maximum heart rate can be calculated by subtracting age from 220. For example, if you are 50 years old, the maximum is approximately 170 beats per minute, which means the second zone is approximately between 100 and 120 beats per minute.
Experts emphasize that accurately reaching this area does not depend solely on feeling; rather, it is preferable to use a smartwatch or fitness tracker to adjust the intensity of the exercise.
Experts explain that the body relies on oxygen to burn fat. During high-intensity exercise, the heart rate increases significantly, reducing oxygen availability and forcing the body to use other energy sources such as carbohydrates. In moderate exercise, oxygen remains sufficiently available, which helps burn fat more efficiently.
Moreover, these exercises allow for longer periods of sustained exertion without excessive fatigue, unlike intense workouts that may force a person to stop quickly. This extra time contributes to strengthening the heart muscle and activating the mitochondria, which are responsible for energy production within cells.
Interest in this type of exercise has increased following research by Dr. Inigo San Millan, which showed that athletes who train for longer periods within this zone can maintain their performance for a longer period.
However, scientific opinions remain divided. Recent studies have shown that high-intensity exercise, such as HIIT, may lead to faster improvements in some fitness indicators. Other studies have found no significant difference in fat loss between intense and moderate exercise.
Therefore, some experts warn against relying solely on "Zone 2" exercises, while others see them as an effective way to encourage people to continue exercising without strain.
In conclusion, most experts agree that the best approach is balance; many professional athletes follow the 80/20 rule, where they devote most of their time to low-intensity exercises, supplementing them with high-intensity exercises.
Thus, success in physical fitness is not only related to exerting maximum effort, but also to choosing the appropriate intensity and maintaining it.
