Energy in sports
Energy is power to do work. Although it is known in various forms, energy is generally measured by therm kilocalories (kcal). There are two forms of energy, potential energy and kinetic energy. Potential energy source obtained everywhere. For example, the body of jumper are up toward the diving board has enormous potential energy. The potential for doing this work clearly demonstrated when the jumper left the diving board and descend quickly into the pool below. Potential energy is also stored in the form of heat and electricity as well as in the chemical composition of such foodstuffs.
Kinetic energy is the energy of motion, and therefore can be observed in sports activities. In athletics we often look at the transfer of potential energy to kinetic energy quickly. In the example cited previously, the potential energy of the jumper quickly transformed into kinetic energy when the descending movement occurs. Similarly, back to football midfielder who sprinted to the middle of the field showing high levels of kinetic energy.
The main concept of the energy concluded in the basic law of physics. That, the energy is not created nor destroyed, but it can change form. So, sportsman does not create energy, also does not destroy or limit. But they continually change the shape of the potential chemical energy into mechanical kinetic energy. Changes in the form of energy is the basis of muscle activity.
Energy Systems in Sports
The energy comes from the breakdown of food is used to form the chemical compound adenosine Triphospate (ATP) which is stored in the mitochondria muscle, though the amount accumulated in the muscles is also very limited, which is 4-6 mM / kg muscle. ATP is only sufficient for fast and heavy activity for 3-8 seconds, so for a long activities required immediate re-establishment of ATP (Fox, 1984: 27).
According to Fox, (1988: 15) The process of reforming the energy in the muscle, can be obtained through three ways:
1. ATP-PC system (Phospagen System)
2. The Lactid Acid System
3. Aerobic System
Various kinds of energy system1. ATP-PC system (Phospagen System)
Phosphagen system involves phosphocreatin. Phosphocreatine is a chemical compound that is also found in muscle cells (Soekarman, 1991: 11). Phosphocreatin (PC) is a little too roughly four times the amount of ATP, but the energy of the fastest PCs contribute to the re-establishment of ATP. Molecules of ATP and PC in the muscle just enough to supply energy to the maximum activity for 20-30 seconds (Bowers, 1982: 20). The maximum activity such as jumps, kicks, punches and other quick movements.
Although the energy that can appear very little, but the backup is particularly useful for sudden movements. Cracking reactions ATP and PC is in the cell takes place very quickly, once ATP is used PCs will soon split and liberate energy to reshape the ATP. According bowers (1992: 79), after 60 seconds of rest, recovery of ATP-PC about 75% and after 180 seconds of rest about 98% of ATP-PC has been reshaped. With the above characteristics can be concluded that the required exercise the right to increase the reserves of ATP-PC in muscle.
2. The Lactid Acid System
These systems convert glucose or glycogen in muscle cell cytoplasm into energy and lactic acid. Lactic acid system occurs when the mitochondria oxygen deficiency so that which should pyruvic acid into the mitochondria transformed into lactic acid (Brooks, 1985: 412-418).
Lactic acid is formed in anaerobic glycolysis will decrease the pH in the muscles and blood, thus inhibiting the enzyme activity or chemical reactions in the body, especially in muscle cells themselves. These barriers lead to accrue muscle contraction-is weak and eventually occur fatigue. (Janssen, 1989: 12; Soekarman, 1991: 16).
Soekarman (1991: 15) concludes the characteristics of the system of lactic acid (anaerobic glycolysis) as follows:
- Causing the formation of lactic acid which can lead to fatigue.
- Does not require oxygen.
- Only use carbohydrates.
- Provide energy to recreate only a few molecules of ATP.
3. Aerobic System
Aerobic energy system is a process of energy formation requires the presence of oxygen O2 so that the process can run perfectly to produce ATP. The aerobic system includes oxidation of carbohydrates, fats and proteins are stored in cells. The oxidation process takes place in the mitochondria. (McArdle, 1986: 75). Energy (ATP) produced by this oxidation process, far more than the anaerobic glycolysis. Protein oxidation only occurs in very forced circumstances.