physiology of fitness nrgsy stems-lesson

8/12/2019 Physiology of Fitness Nrgsy Stems-lesson

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Physiology of Fitness

Energy systems and their role insport and exercise


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Learning Outcomes

List the 3 main energy systems and their cellular fuel

Describe the 3 energy systems giving sports related

examples

Explain why some sports require more of one energy system

than another

Measure and record the bodys responses to different types

of exercise

Explain the recorded measurements

Produce a short magazine article describing the three main

energy systems using examples.


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Actin & Myosin

What are the

contractile proteinsin muscle?

Actin & Myosin

http://www.youtube.c

om/watch?v=gJ309

LfHQ3M

http://www.physics31

10.org/images/240_

actin.gif

The key terms to remember

from that clip are: ATP

ADP + Creatine Phosphate

Myosin

Actin

When ATP is released onto

myosin the chemical bond

breaks releasing a lot ofenergy causing actin and

myosin filaments to contract

ie muscle contraction

Contractile

proteins
http://www.youtube.com/watch?v=gJ309LfHQ3Mhttp://www.youtube.com/watch?v=gJ309LfHQ3Mhttp://www.youtube.com/watch?v=gJ309LfHQ3Mhttp://www.physics3110.org/images/240_actin.gifhttp://www.physics3110.org/images/240_actin.gifhttp://www.physics3110.org/images/240_actin.gifhttp://www.physics3110.org/images/240_actin.gifhttp://www.physics3110.org/images/240_actin.gifhttp://www.physics3110.org/images/240_actin.gifhttp://www.youtube.com/watch?v=gJ309LfHQ3Mhttp://www.youtube.com/watch?v=gJ309LfHQ3Mhttp://www.youtube.com/watch?v=gJ309LfHQ3M


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What is ATP?

ATP is a protein

(Adenosine) with 3phosphates attached

to it

When chemical bonds

are broken, energy isreleased and ATP

becomes ADP

(Adenosine

diphosphate Di=2)

The energy from this

breaking is used to

make muscles contract

The release of energy from ATP


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Energy Systems

What are the 3 main

energy systems thatconvert chemical fuel

from food into energy?

1. Creatine PhosphateSystem

2. Lact ic Acid Sys tem

3. Aero bic Energ y

System

What is this?

The mitochondrion,

shown here, is a tiny

cellular structure that turns

chemical fuel into cellular

energy ie ATP.


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Creatine Phosphate System


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CP System

(immediate energy)

Here ATP is made without

the presence of oxygen.

When exercise intensity is

high, or energy needs areinstantaneous, creatine

phosphate stored in your

muscle is broken down to

provide energy to make

ATP.

Explosive work can be

achieved, but only for short

periods of time at maximum

intensity, as the supply of

creatine phosphate is very

limited, up to 10 seconds.

Act iv i ty

List as many sports activities

as possible that use mainly

the CP system.


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Primary energy source:

Duration of activity:

Sporting events:

Advantages:

Limiting factors:

Stored ATP, CP

7-12 s

Weight lifting, high jump, long jump, 100mrun, 25m swim

Produce very large amount of energy in a

short amount of time

Initial concentration of high energyphosphates (ATP, PC)


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Training The CP System

a) Interval training:eg 1min low intensity 1min high intensity& repeat

- 20% increase in CP (creatine phosphate) stores

- no change in ATP stores

- increase in ATPase function (ATP -> ADP+P)

- increase in CPK (creatine phosphokinase) function(CPK breaks down CP molecule and allows ATPresynthesis)

b) Sprint training:

- increase in CP stores up to 40%

- 100% increase in resting ATP stores


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Lactic Acid Energy System


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high intensity exercise

up to 2 minutes.

ATP is made by the

partial breakdown of

glucose and glycogen.

This is caused byanaerobic glycolysis

Its an anaerobic

process (no O2)

Where does the body store

glycogen? Muscles

Liver

What is the by-product of

anaerobic glycolysis?

Lactic acid

http://www.youtube

.com/watch?v=JLaVIPlPm6g&feature=

related
http://www.youtube.com/watch?v=JLaVIPlPm6g&feature=relatedhttp://www.youtube.com/watch?v=JLaVIPlPm6g&feature=relatedhttp://www.youtube.com/watch?v=JLaVIPlPm6g&feature=relatedhttp://www.youtube.com/watch?v=JLaVIPlPm6g&feature=relatedhttp://www.youtube.com/watch?v=JLaVIPlPm6g&feature=relatedhttp://www.youtube.com/watch?v=JLaVIPlPm6g&feature=relatedhttp://www.youtube.com/watch?v=JLaVIPlPm6g&feature=relatedhttp://www.youtube.com/watch?v=JLaVIPlPm6g&feature=related


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Sporting events:

Advantages:

Limiting factors:

Stored glycogen, blood glucose

12 s3 min

Lactic acid build up, H+ ions build up(decrease of pH)

800m run, 200m swim, downhill ski racing,1500 speed skating

Ability to produce energy under conditions of

inadequate oxygen


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naerobic Threshold The exercise intensity at which lactic acid begins to

accumulate within the blood

The point during exercise where the person begins to feeldiscomfort and burning sensations in their muscles

Lactic acid is used to store pyruvate and hydrogen ions untilthey can be processed by the aerobic system


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The primary source of substrates is carbohydrate

Carbohydrates: primary dietary source of glucose

primary energy fuels for brain, muscles, heart,

liver


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Aerobic Energy System



Sporting events:

Advantages:

Limiting factors:

Glycogen, glucose, fats, proteins

> 3 min

Lung function, max.blood flow, oxygenavailability, excess. energy demands

Walking, jogging, swimming,

walking up stairs

Large output of energy over a long

period of time, removal of lactic acid


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The most importantenergy system in the human body

Blood lactate levelsremain relatively low(3-6mmol/L bl)Primary source of energy (70-95%) for exercise lasting

longer than 10minutesprovided that:a) working muscles have sufficient mitochondria to meet

energy requirements

b) sufficient oxygen is supplied to the mitochondriac) enzymes or intermediate products do not limit the Krebs

cycle

Primary source of energy for the exercise that is

performed at an intensity lower than that of the anaerobic

oxidative system


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Long term energy,

system for lightexercise and every day

movements.

Uses O2

The production ofenergy in the aerobic

system does not start

instantly.... Why?

In groups discuss thisand write down your

agreed answer

Answer:

It takes a few minutesfor the heart to deliver

oxygenated blood to

the working muscles.

Long, continuous

moderate exercise

produces energy using

this system.


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Types of Sport that use each system

Remember, energy at any given time

is derived from all 3 energy systems.

However the emphasis changes

depending on:

the intensity of the activity

the efficiency of your aerobic fitness


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Energy Systems Summary

1. Creatine Phosphate energy system ...for very short high intensity exercise

ADP + Phosphocreatine ATP + creatine

requires no O2 but only enough stored for

about 10secs e.g. power lifting...

2. Lactic Acid Energy System: short-termenergy system

Glucose 2 ATP + 2 lactic acid + heat

Glycogen 3 ATP + 2 lactic acid + heatrequires no O2 but produces energy for high

intensity exercise for up to 6090 secs e.g. 400m

race..


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Energy Systems Summary

3. Aerobic Energy System: long-term energysystem

Glucose +O2 38 ATP + CO2+ water + heat

Fatty acids + O2 129 ATP + CO2+ water

+ heat

physiology of fitness nrgsy stems-lesson

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