One of the most debated topics in exercise and weight loss is the proper intensity of exercise needed for fat loss. Is high intensity exercise more suited for weight loss? Or is lower intensity, longer lasting exercise more beneficial?

During exercise, we use a combination of energy sources. At a high intensity the main source of energy is carbohydrate, while at a low intensity fat is the predominate source. In general terms, most exercise intensities below 70% Maximal Heart Rate will utilize fat as the main energy source, while higher intensities will use primarily carbohydrates. As there is a limit to the amount of carbohydrate that can be stored in the muscles, high intensity work can only be sustained for short periods. We have large stores of fat so low intensity work can be maintained for long periods.

So why would high intensity exercise be used in fat loss it if it uses primarily carbohydrate sources? The answer can be found in the phrase "calories in versus calories out." The major benefit of high intensity exercise is that, while it generally can't be maintained for long periods of time, it allows for a large caloric burn. The higher the exercise intensity, the higher demand the body has for energy, thus more calories the body must burn.

But I am still using carbohydrates, right? Yes, during high intensity exercise the body uses carbohydrate to provide energy. The key here is that the energy used during exercise must be replaced afterwards in order for proper recovery. This is where fat becomes a major player. As we have mentioned, lower intensity activities use fat as a primary fuel source. Rest is certainly one of these situations. The more energy we use during exercise, the more we must replace during our rest periods. Because this is such a low intensity period, fat will be the primary fuel burned in the energy replacement process. Essentially, implementation of high intensity exercise will result in fat-burning after exercise as opposed to during, but the time frame and volume of fat utilization will be significantly increased.

This is not to say that low intensity exercise is not effective in fat loss, as it has been proven effective in many different situations. If you are looking for a more time efficient method that will add some variability to your training, implement higher intensity workouts to your overall exercise program

If you have any questions/comments, please feel free to contact the Body Shop. We are happy to give you a new exercise routine that can keep you reaching your goals!