What does aerobic mean? Aerobic simply describes an activity that requires free oxygen. Aerobic exercises are activities that improve the necessary transportation and absorption of oxygen throughout the body. Aerobic Energy Production is the body’s choice for low to medium intensity activities as well as longer bouts of exercise.
In the middle of aerobic activity, the demands on the heart and lungs for oxygen are strong, and increased cardiac output meets those demands. Aerobic exercise, then, is any activity that increases cardiac output. We also know that stroke volume and heartbeats per minute comprise this total value of cardiac output, but lets look a little closer at this.
The heart sends oxygen-rich blood to the cells so that it can be used to make energy by way of ventricles. These ventricles expand and stretch during exercise so that there is an increase in blood volume to meet the body’s energy demands. Overtime this increases the overall size of your heart. Your heart actually grows with aerobic exercise!
Oxygen is used to produce energy in the body in an ATP synthesis called cellular respiration. ATP is a molecule that muscles need to do work. Cellular respiration is the process used to create energy when we are engaged in aerobic activity and using oxygen, as opposed to anaerobic activity that creates energy without oxygen.
Cellular Respiration uses carbohydrates and fats to produce energy and is slower than its anaerobic counterpart, but has much greater yields and can produce 30 to 32 molecules of ATP, whereas anaerobic energetic production only uses carbohydrates and produces a measly 2 molecules of ATP per cycle. Aerobic activity is the only time fat cells are used to make energy.*
It is important to understand that you are not mechanical. You do not have a switch, and more than likely both processes are happening simultaneously at rest and during exercise. Research has found that with specific activities, they can repeat the type of energy production used by the body by manipulating intensity and duration of exercise.
*Please note that anaerobic activity requires more energy and therefore burns more total calories which can sometimes override the notion that you will burn more fat by just doing cardio. However, like I said we are almost always using both aerobic and anaerobic ATP production.
What kind of goals can be achieved by aerobics? (we already assume ‘look like Jane Fonda’ is one of them.)
- Increasing the overall cardiac output of your heart
- Increasing the size of your heart and ventricles, which will allow for continued elevated cardiac output, not just during exercise, but into the future of your cardiac health.
- Fueling cellular respiration processes in the body with fat cells, training them to use more than just carbohydrates as an energy source.
- Increased Fat Burning when not engaged in Activity.