LAsystem.pdf

Exercise & Sport Physiology Energy systems: Glycolytic system The lactic acid (LA) energy system breaks down the fuel glucose to provide energy. This allows ADP to be resynthesized back into ATP. The LA system takes place in the muscle sarcoplasm and does not require any oxygen so is termed anaerobi...

Exercise & Sport Physiology Energy systems: Glycolytic system The lactic acid (LA) energy system breaks down the fuel glucose to provide energy. This allows ADP to be resynthesized back into ATP. The LA system takes place in the muscle sarcoplasm and does not require any oxygen so is termed anaerobic glycolysis. Features The LA system provides energy to resynthesize ATP during the first 2-3 minutes of high intensity short duration anaerobic activity. If exercise is flat out to exhaustion the LA system may only last for up to 30 seconds. If intensity is lowered then duration can be prolonged for up to a few minutes of anaerobic activity. Associated sports High intensity activity from 10-180 seconds The LA system is the predominant energy system used in… - 400m sprint - 50m-100m swim - Midfield games players Advantages (+) -large glycogen store in muscle/ liver readily available - Resynthesises two molecules of ATP (more than PC) - work aerobically and anaerobically - Easily accessed Disadvantages (-) The LA system is more complex than the ATP/PC system therefore slower to resynthesize (although on the whole still relatively quick). The main limitation of the LA system is due to the onset of blood lactate accumulation (OBLA) Lactic acid… - inhibits enzyme activity - prevents the breakdown of glucose - induces muscle fatigue (OBLA) - stimulates pain receptors - Frees only 5% of potential energy - Peaks at 1min