Coach Marys tast tips #9
On the last post I talked to you about anaerobic systems that produce energy, such as the creatine phosphate and the glycolytic systems; today I will be talking about the aerobic one called aerobic respiration.
The term “aerobic” means the system requires oxygen to function. It is a complex system with many different steps and molecules involved, but it has the simple goal of forming many molecules of ATP to fuel our activities. Unlike the anaerobic systems, the aerobic one can produce energy from several different substrates, so it can utilize carbohydrates, fats, and even proteins to make energy, depending on which is available. These substrates mostly come from our storages of glycogen and fatty tissue, which very rarely run out, allowing this system to work for an indefinite period of time. The aerobic system has two parts, the Krebs cycle and aerobic phosphorylation, and it produces a lot more energy than the anaerobic ones.
The aerobic system is used mainly when our bodies need energy to be produced at a slow rate but for an extended period of time. For this reason, it is the main way our bodies produce energy at rest and throughout the day. When it comes to workouts though, this energy system is the latest one to form ATP and to be used; it is used mainly for longer workouts that do not require energy to be recycled quickly, such as a steady 5km run or a 20 minute workout done at 50-60% intensity. As intensity increases, the aerobic system cannot keep up and is slowly replaced by the anaerobic ones because they can generate energy more quickly. However, as this happens, our bodies start accumulating lactic acid, slowing us back down into an intensity that can be fueled by the aerobic system, therefore decreasing the production of lactic acid. In simple terms, as the length of a workout increases, its intensity and anaerobic input decrease. The opposite is also true, high intensity tend to be quite short and mainly fueled by the anaerobic systems. We really cannot get the best of both worlds!
The transition between anaerobic to aerobic is called the lactate threshold. Lactate threshold is defined as the intensity of exercise required to create lactic acid (via glycolysis) more rapidly than it can be removed by our body, requiring us to drop the intensity and move into an aerobic state. Like any other kind of fitness, this can be trained and bettered; the higher our lactate threshold, the higher intensity we can push and sustain before having to scale back to the aerobic system, which is definitely something good to have for many of the crossfit workouts!
Lastly, I just want to reiterate why it is important for you to have a basic understanding of these systems. As we go to the gym and do different kinds of workouts, we are all aware that some are more strength-based while others are more skill or cardio-base. Now, you should also be able to recognize which workouts target each one of the systems and have a basic understanding of how the food you eat during the day and before you train affects your performance in each. If you have to do a workout that lasts less than 5-6 minutes, make sure to eat the appropriate amount of carbohydrates before showing up at the gym or you won’t perform optimally nor feel very good during it. If it is a more steady, less intense workout, then you might still be able to perform relatively well even if you haven’t had time to eat much before coming in…not that I recommend it anyways though! There are tons more detail that can be added to this topic, but hopefully this little bit of knowledge will help you fine-tune your nutrition and improve your performance at the gym.
2018 03 29