exercise phy pwerpnt

Name: Calena Smith

Topic: The effect of aerobic exercise on muscle fibre function

Key Words

Aerobic ExerciseMuscleMuscle fibreA.T.PaseMitochondriaMyoglobinSlow twitchFast Twitch

Definition of terms

• Aerobic Exercise: is physical exercise that intends to improve the oxygen system.

• Aerobic means "with oxygen", and refers to the use of oxygen in the body's metabolic or energy-generating process. Many types of exercise are aerobic, and by definition are performed at moderate levels of intensity for extended periods of time.

Muscle

• an organ that, by cellular contraction, produces the movements of life

Muscle fibre

• any of the cells of skeletal or cardiac muscle tissue which is an elongated contractile cell that forms the muscles of the body

• are mainly composed of the proteins, actin and myosin.

A.T.Pase

• Enzymes that cause the conversion of A.D.P to release energy

Mitochondria

• are known as the powerhouses of the cell. They are organelles that act like a digestive system that takes in nutrients, breaks them down, and creates energy for the cell.

Myoglobin

• is a protein and has oxygen bound to it, thus providing an extra reserve of oxygen so that the muscle can maintain a high level of activity for a longer period of time.

Slow Twitch

• Muscle fibers that produce energy by converting fats into energy aerobically.

Fast Twitch

• Muscle fibers that produce energy by breaking down glycogen in the absence of oxygen. They produce rapid contractions, but create lactic acid as a by-product.

Types of Muscle Fibre

there are two main type of muscle fibre:

• Type I – often called slow-twitch or slow fibre or highly-oxidative muscle fibres

• Type II – often called fast-twitch or Fast fibers or low-oxidative muscle fibres

Slow Twitch Muscle Fibre

• contain more mitochondria • smaller in size• have better blood supply• contract more slowly

more fatigue resistant than their fast-twitch brothers. 

produce energy, primarily, through aerobic metabolism of fats and carbohydrates. 

Type 1 Muscle Fibre

are only aerobic and contain an abundance of mitochondria (where the Krebs cycle occurs).

The major source of energy for Type I is fat through the Krebs cycle.

They also contain large amounts of myoglobin: a pigment similar to haemoglobin that also stores oxygen – that provides an additional store of oxygen for when oxygen supply is limited

Type II has three subgroups:

Fast Oxidative Glycolytic

Fast Glycolytic

Indeterminate

Fast Oxidative Glycolytic -

Aerobic

burns glucose

mitochondria present but not as many as type I

Fast Glycolytic

• Anaerobic• burns glucose• no mitochondria

produces lots of lactic acid which can enter mitochondria of type I or IIa

heart muscle can utilize all the lactic acid it can get. Any lactic acid left over enters the liver and is reconstitued into glucose.

Indeterminate

undifferentiated fibers -can become type IIa or IIb

The effect of aerobic exercise on muscle fibre

Increase blood capillaries to muscle fibre

Increase in number and size of mitrochrondria

Increase enzymic action (A.T.Pase)

Exercise suitable for slow twitch muscle fibre

• Marathon• Cross country cycling• Swimming• Skating• Skiing• Triathlon, Decathlon, Heptathlon• Running