• ATP – PC System (Anaerobic System): This system works by breaking down food energies (stored in the cells) to produce energy and Adenosine Diphosphate (ADP). From here Phosphate Creatine (found in muscles), a chemical compound, combines with ADP to produce more ATP. This system is used best for high intense events using large bursts of energy.
• Lactic Acid System (Anaerobic System): The Lactic Acid System is‘a fatiguing metabolite of the lactic acid system resulting from the incomplete breakdown of glucose’ (Matthews.D, 2008). This system is used for predominantly intermediate events such as a Rugby
League match. A by product from this system is a Lactic Acid build up, which is known by many athletes as the pain in the legs the next day after competition.
• Aerobic System: This system uses energies from various proteins, fats and carbohydrates. This system releases these energies much slower then the ATP – PC system and therefore allows the athlete to compete at a longer but less intense range. This system is used best for long distance (e.g 1500m runners) athletes.
(See Fig 1 for a detailed graph on the comparisons between intensity throughout all three systems)
Javelin is an event that uses the ATP – PC system. As previously stated the ATP-PC System works by breaking down food energies into energy the athlete can use to compete. This system needs no oxygen to operate therefore this is why it is so effective for a short period of time.