Today let’s look at energy systems and their different types.
The minimum amount of energy required by the body to sustain basic cell functions is called as BMR (Basal Metabolic Rate). BMR is necessary in order to ensure that the energy output through exercise and NEAT (Non Exercise Active Thermogenesis) balances with the energy input through food.
Energy is stored in carbs, fats and proteins. These are broken down to form ATP (Adinosine Tri Phosphate) which are stored in our cells and used while performing body movements.
ATP is broken down to give ADP + Pi + energy
ADP – Adinosine Di Phosphate
Pi – inorganic phosphate compound
Energy – 7.3 kcal / ATP
Once ATP has been used it has to be replenished to produce energy again. Phosphate from PC (Phosphor Creatine) converts ADP to ATP. Occurs without the presence of oxygen, provides energy for high intensity, short duration type activity. For example, during an all-out sprint, the ATP-PC system can supply energy for only 10 – 15 seconds before complete exhaustion.
There are three types of energy system:
- Anaerobic Alactic Energy System
- Anaerobic Lactic Energy System
- Aerobic Energy System
THE ANAEROBIC ALACTIC ENERGY SYSTEMS:
It is an energy system for activities up to 10 seconds. For example, 100m dash, short sprints, etc. Does not require oxygen and does not produce lactic acid build up. As explained earlier, since the ATP fuel stores exhaust pretty fast, the muscles have to wait for the conversion of ADP back to ATP and to restore the ATP fuel stores, since only ATP can fuel muscle cells.
THE ANAEROBIC LACTIC ENERGY SYSTEMS:
This system also does not require oxygen, instead of ATP, this system uses carbohydrates as fuel and as a result lactic acid is formed as a by-product. In the energy system for activities from 10 seconds to 2 minutes, the first 10 seconds is obviously fuelled by ATP. If the ATP fuel stores are not replenished fast enough, the person starts to feel fatigue and this also indicates lack of proper dieting.
THE AEROBIC ENERGY SYSTEMS:
This energy system depends on carbohydrates and fat as fuel; there is no lactic acid by-product as it is a primary source of energy for activities lasting longer than 2 minutes. For example, marathons and swimming.
Anaerobic lactic and aerobic energy system work on the same principle called glycolysis, which is breaking down of glucogen stores to glucose which produces an ATP. It then results in pyruvic acid; the only difference being the presence of oxygen. If oxygen is present it gives another ATP along with carbon dioxide and hydrogen being by-products (aerobic energy system), but without oxygen it forms lactic acid (anaerobic lactic energy system).
Most sports involve all three energy systems, depending upon the task or activity being performed at any given time. For example, football is an aerobic sport, but the quick short sprints in-between is anaerobic lactic. Similarly, running at a moderate pace is aerobic, but sudden increase in pace and pause is anaerobic lactic energy system.