Have you ever wonder how exercise and weight-loss is connected? If so, here is a brief rundown of the science behind the two.
To start, glycogen is the readily metabolized storage form of carbohydrates in our bodies, and it is also our bodies’ first source of energy when we begin an exercise session. Hence, a lot of people engage in consuming a large amount of carbohydrates the night before or the morning of a planned workout. This is otherwise known as “carb-loading.” As we exercise, our bodies will break down the glycogen for power. When all of the glycogen supply is depleted, our bodies will then turn to other sources of energy.
Namely, fat, or triglycerides, is utilized next as fuel for our bodies. While it would be convenient for weight-loss purposes if our bodies naturally preferred to burn fat for energy, burning fat, unfortunately, does not provide energy as efficiently as carbohydrates. In short, our bodies can extract much more energy from carbohydrates than the same amount from fat, so our bodies instinctively burn through our glycogen supply before touching our fat storage.
So, how do these concepts interact with exercise and weight-loss? Since glycogen is preferentially metabolized and used for energy, our bodies will burn that during the first 20-30 minutes of physical activity before shifting to burning triglycerides. This may add some difficulty for individuals who are trying to lose weight but do not exercise for an adequate amount of time. In other words, if you exercise for only half an hour or less, then only the carbohydrates stores in the liver are utilized, while the fat reserves are left untouched.
Does this mean that you should start lengthening your workout routine? Yes and no. A healthy routine incorporates both aerobic activities with muscle strengthening. Check out our article about moving towards a healthier lifestyle for specific recommendations. Also, keep in mind that aside from exercise, dietary modifications is another important factor when you are trying to lose weight. Remember that energy metabolism is not an “all-or-nothing” phenomenon. Our bodies are constantly fine-tuning the appropriate ratios of carbohydrates, fat, and protein metabolism to supply us with energy. So, as we modify our diet and exercise routines, our bodies will also be adjusting. Consult your health coach, fitness instructor, and/or medical provider regularly to make sure the combination of your current diet plan and workout routine is the best mixture to optimize your weight-loss endeavor.