If you go to the gym, on the heart rate chart you’ll see listed a “fat burning zone”. Theoretically, the fat burning zone is working out between 55-60% of your maximum heart rate. At this intensity your body uses more fat than carbohydrate for energy. As your intensity increases, you burn more carbohydrate. This concept sounds highly appealing, but does it really help burn more fat?
During cardiovascular exercise we use two main sources of fuel – carbohydrate in the form of glucose and fat. At different intensities we burn different percentages of these. At a lower intensity, as mentioned above we use a greater percentage calories from fat – around 50%. At a higher intensity we use a greater percentage of calories from carbohydrate.
Sound good? Don’t be deceived. Remember fat loss and therefore weight loss comes down burning off more calories than we take in. Exercising at a higher intensity burns more calories, therefore is a better workout for weight loss irrespective of whether you burn fat or carbohydrate calories during exercise.
High intensity exercise also has other benefits that don’t come with working out at the fat burning zone. High intensity exercise produces something known as EPOC (excess post exercise oxygen consumption). This is an increased rate of oxygen intake to replace the “debt” that comes from high intensity exercise. This also causes our body to burn fat, using our fat stores as energy.
As a way to get started with high intensity exercise, try interval training. Walk or jog slowly for a minute, then sprint as fast as you can for thirty seconds followed by a walk or jog for a minute to recover. Repeat for the duration of your workout.
While low intensity exercise is still beneficial for health and well being, high intensity exercise is the way to go if you’re wanting to burn fat and improve your fitness.