Fat Burning Myths

“Training in the “fat burning zone” is necessary to loose weight”

The “fat burning zone” (sometimes referred to as “Fat max”) is an intensity zone at about 55-60 % of maximum heart rate. This is the intensity where the highest percentual amount of fat is used as fuel. As intensity increases, we become more reliant of carbohydrates, in the form of blood glucose and glycogen.

It is a common belief that training in the “fat burning zone” is key to weight loss, but that is far from accurate. Just because you are using high amounts of fat as fuel during workouts does not mean that you will achieve weight loss per se.

                                                    “A state of energy deficit is necessary for weight loss to occur”

If fat or carbohydrates are predominantly used as fuel does not matter. What matters is the amount of energy (“calories”) that are expended during a workout (and hours after the workout). The training intensity is therefore irrelevant if the goal is to loose weight.

For weight loss to occur it is necessary to achieve a state of energy deficit (“negative energy balance”). This forces the body to start using its energy stores (in the form of body fat) as fuel. A state of energy deficit can be achieved by increasing the amount of physical activity and reducing energy intake by consuming less energy trough food/drinks (i.e., “moving more, eating less). This sounds easy in theory but it’s hard to do for most people in the modern world.

                                                                              “You can’t out exercise a bad diet

Expending energy trough exercise is time consuming and physically/mentally demanding. As an example, it would take an 80 kg man approximately 60 minutes or running at a moderate pace to “burn” 1000 kilo calories, but it would take 5 minutes for the same person to consume 1000 kilo calories by eating a pizza.

Limiting energy intake by watching what you eat it is therefore the most important part if you want to achieve weight loss.


Being physically active is still important and it has many positive health benefits but only relying on that (without limiting energy intake) will lead to minimal or zero weight loss. To put it in other words: “you can’t out exercise a bad diet”.



Are you interested in learning more exercise and personal training?

Check out the personal trainer course at IPTA – International Personal Trainer Academy.