I have said this numerous times before, but I will say it again because it is so true: moto is one of the most dynamic sports on the face of the planet. Simply doing cardio for hours on your road bike will not prepare you enough for a 20 minute moto. The body relies on different systems to fuel itself during physical activity and the endless cardio only taps into one of these energy systems. When you know what to train, you can properly set up your workouts for the right time of the year.
Your energy systems are the means of producing energy that is called ATP. This is molecule is essential for muscular contraction. If you have no ATP, you aren’t going anywhere. Depending on the intensity of the activity, you will get most of your energy from one of three systems: oxidative, glycolytic, or ATP-PCr system. All three systems are always being used, but it is just a matter of which one is in the “driver seat.”
The first system is the oxidative. This is the slow and steady way of getting energy. Generally, this is used when activity is over 2 minutes. Because it uses oxygen, this aerobic process takes place in the mitochondria of your cells. Remember those things? They used to call them the power houses of the cells when I was in high school. As you train in this system more and more, your body will produce more mitochondria in order to keep up with the demand for ATP. For the most part, the lower the intensity, to more fat is utilized.
The next system is the glycolytic. In this system, things are getting a more intense and the heart rate is climbing. At this point, you start to use a little less fat and more carbohydrate. This is where glycolysis occurs and breaks down glucose or glycogen. Since this is a higher intensity, if there is oxygen (aerobic), then the glucose can be broken down and sent to another cycle for ATP. However, when there is no oxygen (anaerobic), the glucose is sent to a different cycle for ATP and eventually is converted in lactic acid, but it can be dissipated quickly. This system is used when activity is under 2 minutes.
The final system used is the ATP-PCr system (CreatinePhosphate) . This is utilized when you are going all out. Unlike the oxidative system where you are getting plenty of ATP, the PCr system only generates small amounts. It cannot be sustain for very long before lactic acid and fatigue take place. The main source of fuel here are carbohydrates. The time for this system is very short, less than 30 seconds.
This is an extremely brief overview of these systems. However, if you can understand what is going on, you will be able to train yourself more efficiently. Like the old saying goes, work smarter, not harder. Tomorrow I will tie this in with the VO2 max so you get a better understanding.