The aerobic energy system Flashcards
Rate and yield
The aerobic system produces energy by COMPLETELY breaking down Glucose when sufficient oxygen is available. Energy is produced at a slow rate (Glycogen 1 mol/min and Triglycerides <1 mol/min) due to the complex aerobic chemical reactions that take place. However, a large yield (- 38 ATP per glucose molecule, and 441 ATP for every triglyceride) enabling to sustain activity for a long period of time.
Fatigue- fuel depletion (glycogen)
If activity’s last for longer than 90 minutes athletes will begin to fatigue to due glycogen stores depleting. The depletion of muscle glycogen stores results in an increased reliance on fat metabolism. As triglycerides are more complex to break down, they have a greater oxygen cost. Therefore, energy for ATP resynthesis is produced at a slower rate, and muscle contractions must slow down. Which therefore, forces the runner to slow down, decreasing performance.
Fatigue- theromreulatory fatigue
The body undergoes a process of thermoregulation in an attempt to regulate body temperature. To do so, the body redistributes a higher percentage of cardiac output to the skin, causing vasodilation of blood vessels around the skins surface. The blood near the skin, releases sweat (blood plasma) which evaporates as we exercise (Sweating). As a result, less plasma means blood viscosity increases (thicker) and this makes it harder for the heart to pump blood. Less blood volume results in decreased stroke volume and therefore less blood goes to muscles unless heart rate increases. Due to a decreased in o2 to the working muscles there is less oxygen available for energy production, in turn ATP is resynthesised at a slower rate. Forcing the athlete to slow down….
Recoverey - glycogen depletion
The best type of consumption post exercise, is a combination of protein and carbohydrate. This should be consumed at a ratio of 1:4 protein to carbohydrates to support glycogen replenishment.
Protein is essential for boosting insulin release to improve muscle glycogen restoration and provide building blocks for muscle growth and repair.
By consuming both protein and carbohydrates in combination for recovery you:
• Increase muscle repair
• Speed up restoration of muscle glycogen stores
Aiding to return the body to pre- exercise conditions
