Energy is what makes our body alive. Several kinds of energy exist in biological systems.
- Electrical energy – nerves, muscles.
- Chemical energy – synthesis of molecules.
- Mechanical energy – contraction of muscles.
- Thermal energy – body temperature maintaining.
Our muscles use mechanical energy to contract and keep us alive and mobile. You are able to kick the ball, and then run after it thanks to a number of complicated processes that produce the needed energy. Our muscles use energy by breaking foodstuffs in a manner that conserves most of the energy contained in the bonds of the carbohydrates, fats and proteins. The final product of the breakdown must be a molecule that cell can use to produce energy – ATP (Adenosine Triphosphate).
Cells use ATP as primary energy source. In ATP , three phosphate molecules are linked by high-energy bonds. When a bond between the phosphates is broken energy is released and may be used by muscles. We would never get tired if the ATP was available all the time, but after the bond between the phosphate molecules is broken and energy released ATP reduces to a lower energy state, becoming adenosine diphosphate (ADP) and inorganic phosphate (Pi). The other important think to know is that ATP is not very stable molecule, and that’s the reason our body doesn’t keep a lot of it ready to use. On the other hand ADP is very stable. Our body has adopted techniques to turn ADP to ATP by adding phosphate molecule. The ready ATP that our body keeps can supply energy for no more than 2-3 sec. There are three ATP sources – Immediate sources of energy, Short-Term sources of energy and Long-Term sources of energy. The immediate source of energy and the short-term source of energy are Anaerobic (without oxygen). The long-term source of energy is Aerobic (with oxygen).
The anaerobic sources of energy are simpler and could supply ATP without the need of oxygen (air). The immediate source of energy simply adds Phosphocreatine (PC), or also known as creatine supplement to ADP to produce ATP. Unfortunately, the PC store in muscle lasts only 3 to 5 sec. when the muscle is working maximally.
The short-term source of energy produce ATP by the break down of glucose in process called glycolysis. It can supply ATP for no more than 2 minutes of maximal work.
The long-term source of energy produces ATP by using mainly carbohydrates, fat and oxygen
Carbohydrate and fat + O2 = ATP
ATP production via aerobic mechanisms is slower than production from the immediate source of energy and the short-term source of energy. During maximal work such as running it may be 2 or 3 min. before the ATP needs of the cell are met completely by this aerobic process. The long-term source of energy is very important and useful for people that are trying to lose weight and burn fat. But you should also know that getting into aerobic stage of producing energy (burning carbs and fat), and staying in it may be hard. Walking, jogging and running for more than 10 min. are some of the activities, that will make you get to that aerobic stage. Faster pulse and breathing are the tell-tale signs for reaching an aerobic stage of energy production.
Knowing more about ATP, and the ways our body produces energy, will certainly help you build a plan for your next workout or sport activity.