Transcript Physiology of Fitness

Physiology of Fitness
Energy systems and their role in
sport and exercise
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 body’s responses to different types
of exercise
• Explain the recorded measurements
• Produce a short magazine article describing the three main
energy systems using examples.
Chemical fuel
• Your body’s ability to extract energy from food and
transfer it to the contractile proteins in your
skeletal muscle determines your capacity to
exercise at different durations at different
intensities. This transfer of energy occurs as a
result of thousands of chemical reactions.
• The muscles use a fuel called
• ATP (adenosine triphosphate).
ATP
Energy is stored in the chemical bond
ATP =
A-P-P--P Lots of energy stored
between 2nd & 3rd
phosphate groups
When this bond is broken energy is released
– allowing myosin to attach to actin and muscle
contraction to occur.
ADP =
A-P-P
(creatine
P = Phosphate
phosphate)
ADP will then bind again with a phosphate
group and energy is stored that can be
used later.
Actin & Myosin
• The key terms to remember
• What are the
from that clip are:
contractile proteins
• ATP
in muscle?
• Actin & Myosin
http://www.youtube.c
om/watch?v=gJ309
LfHQ3M
http://www.physics31
10.org/images/240_
actin.gif
• ADP + Creatine Phosphate
• Myosin
Contractile
proteins
• Actin
• When ATP is released onto
myosin the chemical bond
breaks releasing a lot of
energy causing actin and
myosin filaments to contract
ie muscle contraction
What is ATP?
• ATP is a protein
(Adenosine) with 3
phosphates attached
to it
• When chemical bonds
are broken, energy is
released 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
Energy Systems
• What are the 3 main
energy systems that
convert chemical fuel
from food into energy?
1. Creatine Phosphate
System
2. Lactic Acid System
3. Aerobic Energy
System
What is this?
The mitochondrion,
shown here, is a tiny
cellular structure that turns
chemical fuel into cellular
energy ie ATP.
Creatine Phosphate System
CP System
(immediate energy)
• Here ATP is made without
the presence of oxygen.
• When exercise intensity is
high, or energy needs are
instantaneous, 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.
Activity
List as many sports activities
as possible that use mainly
the CP system.
Lactic Acid Energy System
• This is for high
intensity exercise
lasting up to 2
minutes.
• ATP is made by the
partial breakdown of
glucose and glycogen.
This is caused by
anaerobic glycolysis.
• Where does the body store
glycogen?
• It’s an anaerobic
process (no O2)
• http://www.youtube
.com/watch?v=JLa
VIPlPm6g&feature=
related
• Muscles
• Liver
• What is the by-product of
anaerobic glycolysis?
• Lactic acid
Recap
Lactic Acid
Creatine Phosphate
Energy System
Energy System
Anaerobic g________ is the
breakdown of ________ and
_________ to produce _ _ _
This energy system can sustain
high intensity exercise for
how long? _____
The by product is called
_______ ____. It can impede
muscle contraction and
cause fatigue.
It is the imm_________
energy system needed when
exercise intensity is ______,
or energy needs are
instantaneous.
C_______ p________ is broken
down to provide energy to
make _ _ _
When ATP is released onto
m______ the chemical bond
breaks releasing a lot of
energy causing a____ and
m_____ filaments to contract
ie muscle contraction
Aerobic Energy System
• Long term energy,
system for light
exercise and every day
movements.
• Uses O2
• The production of
energy in the aerobic
system does not start
instantly.... Why?
• In groups discuss this
and write down your
agreed answer
Answer:
It takes a few minutes
for the heart to deliver
oxygenated blood to
the working muscles.
Long, continuous
moderate exercise
produces energy using
this system.
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