Energy Systems 3/12/07

Learning Objectives To understand when we use the two energy systems –Aerobic Energy System –Anaerobic Energy System To Understand the term ‘Oxygen Debt’

How do Muscles Work? Anything you do needs energy. When muscles work they have to lengthen and shorten. For this to work your muscles need energy

The Energy Systems The Anaerobic Systems: –The Creatine Phosphate System –The Lactic Acid System Glucose » Energy + Lactic Acid The Aerobic System Glucose + O 2 = Energy + CO 2 + Water

Making Energy Available to the Body  The glucose enters the small intestine where it passes into the blood.

Anaerobic System When Creatine Phosphate runs out, the muscles call upon the stores of GLUCOSE ( Glycogen ). But there is a side effect with this type of energy system. A waste product called PYRUVIC ACID is produced. This in itself is OK if levels of activity are reduced to enable this Pyruvic Acid to be broken down by OXYGEN into CARBON DIOXIDE and WATER. However, if levels of activity are not reduced and not enough oxygen is being breathed in, then this Pyruvic Acid is not broken down and converts into LACTIC ACID.

Anaerobic System After a while it will make the muscle ache and eventually it will cause cramp, and the muscles will stop working. The athlete has to rest while blood brings fresh supplies of oxygen to the muscles. He/She is repaying back the OXYGEN DEBT.

Anaerobic System (Lactic Acid System)

The Aerobic System This system is used during lower levels of activity when there is enough OXYGEN being delivered to the working muscles to clear away ALL the Pyruvic Acid. At lower levels of activity FATS can be used as a muscle fuel. This preserves its stores of GLUCOSE for as long as possible. As a general rule, the more intense the activity, the more GLUCOSE is used instead of FAT.

The Aerobic System

Energy Systems in Sport 100% Aerobic Anaerobic Cross Country Skiing Tennis Football Rugby 100m Sprint 1500m race Downhill Skiing Hockey Marathon running

Aerobic Respiration – With Oxygen The Process of Aerobic Respiration Energy for Muscles to contract and create Movement Water Carbon Dioxide Glucose Oxygen

Anaerobic Respiration – Without O2 The Process of Anaerobic Respiration Glucose Energy for muscles to contract and create movement Lactic Acid

Oxygen Debt Question: How do sprinters pay back their oxygen debt at the end of a race? Answer: Sprinters will continue to breathe more deeply and rapidly for a number of minutes at the end of their race. This will enable them to pay back the oxygen debt, and allow lactic acid levels to fall.

Learning Objectives To understand when we use the two energy systems –Aerobic Energy System –Anaerobic Energy System To Understand the term ‘Oxygen Debt’ Homework Revise the Respiratory System and the Circulatory System.

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