Exercise Physiology

1) Compare and contrast the energy systems used by yourself completing a run/swim/run event of 200m running, 50m swim and 200m running compared to an elite athlete competing in an ironman triathlon (3.8km swim, 180km cycle, 42km run) (2A) (20 marks)

200m run, 50m swim, 200m run

Lactic acid system, does not require oxygen, it is the dominant source of energy during high intensity activities lasting 30-60 seconds, (200m run) (50m swim). Lactic acid builds up when exercising at a high level and eventually results in fatigue. It is removed during recovery when adequate oxygen becomes available. Following the initial 10 -12 seconds of ATP energy system, PC (energy) stores are empty and need another energy system to supply the energy. The body needs to find an alternate fuel and the lactic acid system becomes the dominant supplier of ATP. This system involves the partial breakdown of glucose to form lactic acid in a number of chemical reactions know as glycolysis. The glucose for this process comes from either glucose stored in the blood or from the breakdown of glycogen in the liver or muscle.

3.8km swim, 180km cycle, 42km run

Aerobic System, the production of ATP requires oxygen, it is capable of creating the largest amounts of ATP. Carbohydrates and Fat can be used to fuel this system by special chemical reactions. Dominant source of ATP production during moderate intensity and prolonged exercise. The carbohydrates produces ATP faster than fat, thats why athletes eat lots of carbohydrates before the race, but we can only store enough carbs to fuel us for 2 hours. The respiratory and cardiovascular systems work together to provide oxygen to the working muscles.

Although both of these events rely on one energy system in particular, in theory, each energy system is working together, adding to the main system and helping replenish the energy stores.

Compare

Both systems use Carbohydrates as their fuel source. Carbohydrates come from foods such as pasta, potatoes and bread The carbohydrates are the first nutrient that is used to supply energy, followed by fat, then protein. Most people think that protein is the first nutrient to be used and that’s why people have lots of protein before an event, but in fact this weights your body down. Starch, Cellulose and Glycogen are all types of Carbohydrates that fuel the body. There are 2 types of Carbohydrates, Simple and Complex. Simple Carbohydrates are found in things such as milk fruit.