The key to burning fat is the 30 minute threshold

When it comes to losing weight, a big hurdle to overcome is the general lack of understanding about how the body uses energy in the form of sugars and fats during a cardiovascular workout.

sugar processing

Carbohydrates are broken down into glucose and glycogen, also known as sugars. Glucose maintains blood sugar levels and is used by both the brain and heart for energy. Glycogen is stored in the liver and muscles. Any extra glycogen is turned into fat. Glucose and glycogen can be broken down for energy without the need for oxygen. This is known as anaerobic metabolism and is used during anaerobic activities like jumping, sprinting, or the dreaded “burpee.” This means that most sugars are used up during short, intense periods of exercise.

fat cells

Fat cells are basically energy storage areas for the body. Believe it or not, your body needs fat to survive. However, too much fat (or obesity) is dangerous because it can inhibit normal body functions or cause you a great deal of stress. The problem with this stored energy is that it cannot be broken down very quickly. Therefore, fat stores can only be broken down through aerobic activity (eg, running, swimming, or cycling for long periods of time).

training intensity

To achieve the “fat burning zone”, one must be at the right intensity. That is, you should exercise between 60% and 70% of your predicted heart rate based on your age and resting heart rate. Anything higher than 70% will cause your body to burn a higher percentage of sugars and fewer carbs (not a bad thing, but more on that another time). When you are between 60-70% of your target heart rate, you are burning the maximum amount of fat your body is capable of burning.

The 30 minute threshold

There is one more important fact that we need to discuss. To get into the fat burning zone, the body must use a large amount of sugars stored in the muscles before it can begin to break down fat for energy. This is a process that usually takes around 20-30 minutes. This means that a 30-minute activity, even an aerobic activity like running or walking, doesn’t start to tap into fat stores until the end of the workout!

While 30 minute workouts do have a role and can help achieve better fitness levels, it is not something that helps reduce body fat levels. Only those aerobic activities that last more than 30 minutes, approaching an hour or more, will help reduce the amount of fat stored in the body.