mmoI/L lactic acid
ANSWERS TO CHAPTER REVIEW QUESTIONS
(b) The use of CHOs for ATP production greatly
increases at around 85 per cent VO2 max
because the body is entering anaerobic
metabolism that uses only CHOs as a source.
Below 85 per cent there may be some use of fat
for ATP production.
8. (a)
3–9
Anaerobic systems
Aerobic system
Exercise intensity
Figure 2.22:
Probable LIP for an elite AFL player
moderate
versus no
physical
activity
404
Energy contribution (%)
(b) Because the athlete is working anaerobically,
the high lactate and hydrogen ions levels force the body to go into an oxygen deficit
live it up 2 fig 2.22
situation.
(c) ‘Lactate threshold’ is defined as the
exercise intensity that brings on
substantial increase in blood lactate
during a single incremental test. This
can be between 3 and 9 mmol/L. OBLA
is defined as the exercise intensity at
which blood lactate concentration reaches
4 mmol/L during an incremental test.
9. (a) Line A: slow jog
Line B: 400-metre athletic race
Line C: a fitness run, swim or cycle, in which
the level of effort is at a steady state
Line D: a 3000-metre athletic race with a
number of surges during the race; or a
triathlon cycling leg where there are a number
of hills.
(b) Because the body always has some lactic acid
in it
(c) Because at the onset of exercise, lactic-acid
levels increase. If the exercise levels remain
below the lactate threshold, then spare oxygen
is available to work on the accumulated lactic
acid and convert it to ATP stores and at the
same time reduce the lactic acid levels in the
bloodstream.
100 2.20, possible
10. (a) Based on data from figure
reasons include:
fit of vigorous versus
• Freeman would have a higher tolerance to
75
erate physical activity
her building lactate levels.
• Freeman’s phosphate energy system has a
greater capacity to enable
her to continue
Benefit of
50
Live it up 2
25
Anaerobic glycolysis
using this source of ATP production for
longer than the other runners.
• Because she may have more disposable
oxygen, Freeman is able to more efficiently
metabolise the building lactic-acid levels
into new ATP.
• Freeman has higher levels of the relevant
enzymes needed for both the ATP–PC and
anaerobic glycolysis energy systems.
(b) The ATP–PC system (also known as the
Phosphate, PC, or CP system)
(c) Because the body is effecting an explosive
change from stationary inertia to moving
inertia, both maximal speed and strength are
needed for this; hence, the quickest available
source of ATP production is employed.
(d) During the third 100-metre split of the
race, each of the runners displays a drop in
running speed. This represents a significant
drop when compared to the second, where
each of the runners achieved their fastest
100-metre split. Only the OBLA and building
blood levels of lactic acid and hydrogen ions
can cause this.
(e) The OBLA occurs when the normal resting
circulatory system levels of lactic acid and
hydrogen ions begin to rise, as anaerobic
glycolysis causes intra-muscular levels of
each to rise and disperse into the circulatory
system. At the same time, blood plasma levels
of H+ have an effect on the contractile abilities
of actin and myosin. In both aerobic and
anaerobic activities, the OBLA is not a cause
of diminishing performance.
(f) Because of Freeman’s highly trained state
and her ability to tolerate high levels of lactic
acid and hydrogen ions, she would be able
to continue to function smoothly at high
levels. At the end of the race these could be
10–15 mmol/L lactic acid blood levels. Elite
athletes have been measured at much higher
levels while still being able to carry out lactate
tolerance training. However, as the 400-metres
is a one-off anaerobic effort of only around
50 seconds, Freeman’s post-race levels would
not have been maximal. Her ability to keep
functioning fairly smoothly under these
anaerobic conditions is possible because of the
interval training she would have carried out.
This training would have stressed and trained
her body’s lactate tolerance.
(g) • For LT — 3–9 mmol/L • For OBLA — 4 mmol/L
(h) The discomfort caused by the unfit individual
Aerobic energy
reaching their LIP would have adversely
affected their running style due to a lack of
(j) Reasons for the divisions in each of the three
pie charts are included below.
• First 200 metres: The PC system is important
for the drive from the starting blocks and
the achievement of the desired top speed.
The anaerobic glycolysis system begins to
create a lot of ATP from about 3–5 seconds,
30%
along with the associated increase in lactic
30%
ATP–PC
25%
acid and hydrogen ions. From about 30%
ATP–PC
25%
Aerobic
glycolysis
15–20
seconds, the aerobic glycolysis
ATP–PC
25%
Aerobic
glycolysis
system
begins to contribute ATP to the
First 200 m of race
Aerobic glycolysis
First 200 m of race
energy needs of the event.
First 200 m of race
• Last 200 metres: The PC input has become
45%
negligible, as its primary importance was in
45%
Anaerobic
glycolysis
the acceleration phase of the race. With the
30%
45%
Anaerobic
glycolysis
building lactate and hydrogen ions during
25% glycolysis ATP–PC
Anaerobic
the third 100-metre split, the efficiency of
Aerobic glycolysis
the anaerobic glycolysis has deteriorated.
First 200 m of race
Matching this has been the growing
importance of the aerobic glycolysis system
in creating the required ATP for the race.
45%
• Total race needs: Because the running time
Anaerobic glycolysis
is around 50 seconds, the split between the
anaerobic and aerobic systems in terms
of ATP production slightly favours the
65%
anaerobic systems.
<5%
65%
Aerobic
glycolysis
ATP–PC
<5%
11. (a) >95% of max HR; <10 seconds activity time
Second 200 m of race
65%
Aerobic
glycolysis
ATP–PC
<5%
(b) Responses could include: 100-metre elite male
Second 200 m of race
Aerobic glycolysis
ATP–PC
athletic sprint; 60-second athletic sprint for
Second 200 m of race
most adult males and females; any athletic
30%
Anaerobic
30%glycolysis
field event; springboard diving; cycling
Anaerobic
30%glycolysis
velodrome 200-metre sprint; individual skill
Anaerobic glycolysis
movements in most team games.
65%
<5%
(c) Advantages:
Aerobic glycolysis
ATP–PC
Second 200 m of race
• Produces quickly
• Allows quick transfer of stationary-tomoving inertia
30%
• Quickly replenishes, enabling repetition
Anaerobic glycolysis
of duplicate effort within 5 minutes of first
55%
effort
55%
Anaerobic
glycolysis
• Does not rely on energy sources from
55%
Anaerobic
glycolysis
outside the muscle
Anaerobic glycolysis
• Does not rely on oxygen being available.
Total race time
Disadvantages:
Total race time
• Depletes quickly
35%
Total race time
• Only allows maximal effort up to 35%
Aerobic glycolysis
10%
55%
35%
10 seconds
Aerobic
glycolysis
10%
ATP–PC
Anaerobic
Aerobic glycolysis
glycolysis
• Relies on muscle stores of ATP and PC
10%
ATP–PC
ATP–PC
• Needs aerobic conditions to replenish ATP
and PC stores.
12. (a) 85–95%
max HR; 5–35 seconds activity time
Total race time
(b) Responses could include: 400-metre athletic
35% 2.23: track race; cycling velodrome male Figure
Aerobic glycolysis
10%
1-kilometre
time trial; elite male and female
Percentage estimate contributions of the three
ATP–PC
100-metre
swim
race.
energy systems at stages of the race
familiarity with the feeling. Their body’s
ability to continue smooth performance
would be significantly more noticeable than
Freeman’s.
(i) Refer to the pie charts in figure 2.23 below.
Answers to Chapter Review Questions
ANSWERS TO CHAPTER REVIEW QUESTIONS
live it up 2 fig 2.23
live it up 2 fig 2.23
live it up 2 fig 2.23
405
ANSWERS TO CHAPTER REVIEW QUESTIONS
406
(c) Advantages:
• quickly available
• enables near maximal effort for longer than
ATP–APC energy system
• does not rely on oxygen being available
• does not rely on energy sources from
outside the muscle
• quick recovery time aided by active
movement
• toxic by-product (LA) is able to be
metabolised to ATP during aerobic recovery.
Disadvantages:
• not as quickly available as ATP–PC energy
• does not enable effort for as long as the
aerobic energy system
• cannot rely on oxygen being available
• can only use energy sources from within the
muscle
• requires active recovery time to promote the
return to active movement
• toxic by-products (LA and H+) reduce the
smooth action of the crossbridges within
the sarcomere.
13. Australian Football is a fine example of a team
sport that demands fitness across all components
and energy systems. Muscular strength is needed
for tackles and man-on-man contests; it combines
with speed for the necessary muscular power to
accelerate into space or away from an opponent,
to leap for marks, or create clearing kicks or
attacking handballs.
Energy for each of these skills individually
comes from the ATP–PC system. However, as
the game progresses and the range of skills
needs continual repetition, the required ATP–PC
recovery time of at least three minutes is generally
unavailable. Therefore, the body gradually
becomes more dependent on the anaerobic
glycolysis system to create ATP. This is reasonably
effective but comes at a price. The LIP and the
building lactate and hydrogen-ion levels make the
player become aware of fatigue and an increasing
desire for rest.
Underlying all these efforts is the aerobic
glycolysis system. This is continually making
ATP generally available for bodily needs, but
is also working to create new stores of ATP and
PC within the working muscles. When enough
oxygen is available, it is also reworking lactate
into renewed ATP stores within the muscles and
body systems that may not be working as hard as
the muscles.
Agility and its aligned flexibility are needed
to evade opponents and turn quickly to kick,
handball or tackle in unexpected situations. Local
muscular endurance, with the many repeated
Live it up 2
efforts (see Chapter 5 for activity analysis), is
essential for the successful completion of the
game. Aerobic power is the underlying fitness
component, with top players like Luke Ball
covering up to 20 kilometres or more in one game,
while having to sprint and complete precise
power movements throughout this impressive
total distance!
CHAPTER 3 Conversion of food to
energy
1. See the glossary on page 435 for definitions of the
key terms in this chapter.
2. Recommended daily percentages of carbohydrate,
fat and protein are as follows:
Carbohydrate: 55–60 per cent
Fat: 20–30 per cent
Protein: 15 per cent
3. Vitamins assist chemical reactions in the body by formulating parts of enzymes or coenzymes,
which assist in the metabolism of carbohydrate
and fat. Minerals play an important role in muscle
contraction, nerve transmission, fluid balance and
assisting enzymes in energy production.
4. Unsaturated fat is the most beneficial form of fat to consume as the body cannot produce it.
Unsaturated fat also reduces low-density
lipoproteins (which are responsible for blocking
arteries).
5. A weight-lifter needs fuels that can supply energy
for high-intensity, short-duration activities. Stored
phosphocreatine and glycogen supply energy for
these activities. A long-distance runner requires
fuels that can supply the body over a long period
of time, but at a sub-maximal workload. Glycogen
and fat are necessary fuels for this particular
athlete.
6. Water is suitable for exercise lasting 60–90 minutes.
Beyond that time frame, sports drinks that contain
carbohydrate and electrolytes are essential to
replace fluid, as well as the sodium and potassium
lost in sweat.
7. Thirst is a sign of dehydration. If you do not drink until this point then your body is already dehydrated and your performance may already be suffering as
a consequence.
8. By knowing a food’s glycemic index, an athlete is
better able to decide the most beneficial time to
ingest that particular food. 9. Foods that have a low glycemic index take longer
to digest and release energy over a longer period.
These are best ingested prior to activity for
sustained energy without the insulin surge.
10. A high-GI index food releases sugar rapidly into
the system and raises blood glucose levels. This
results in insulin being released by the pancreas
informing the working muscles that they should
not take up more blood glucose. The muscle cell
glucose level is then compromised, leading to
fatigue and hunger. Therefore, a high-GI food
should not be ingested as part of a pre-event meal.
Sugary foods with a high glycemic index are best
ingested during recovery, as they rapidly release
glucose to muscles to replace the muscle glycogen
stores consumed during exercise. CHAPTER 4 Fatigue and recovery
Athletic
event
Specific cause of fatigue
100-metre
sprint
PC depletion
200-metre
swim
PC depletion, metabolic by-products: LA and H+ accumulation
Half- marathon
PC depletion, metabolic by-products:
LA and H+ accumulation, glycogen
depletion and dehydration
Hawaiian
ironman
PC depletion, metabolic by-products:
LA and H+ accumulation, glycogen
depletion, fat depletion and
dehydration
6. Fast-twitch fibres fatigue as a result of fuel
depletion and lactic acid and hydrogen ion
accumulation. On the other hand, slow-twitch
fibres tend to fatigue as a result of glycogen
depletion and dehydration.
Answers to Chapter Review Questions
ANSWERS TO CHAPTER REVIEW QUESTIONS
1. See the glossary on page 435 for definitions of the
key terms in this chapter.
2. Three factors influencing the causes of fatigue are:
• The type of activity being undertaken
• The intensity of activity being undertaken
• The fitness level of the athlete.
3. The three levels of fatigue are: local, general and
chronic.
• Local fatigue is experienced in a particular
muscle or group of muscles following a specific
training session or performance (e.g. quadriceps
following 30 seconds of squats).
• General fatigue is an overall body fatigue as a
result of an extended training program (e.g. after
a weights session at the gym).
• Chronic fatigue is long-term fatigue caused by
the body’s defensive mechanisms breaking down
over time. This fatigue can be a combination of
both mental and physical fatigue.
4. Common causes of fatigue in athletes include:
• Fuel depletion
• Metabolic by-products
• Dehydration and increased body temperature.
5. Causes of fatigue within anaerobic and aerobic
activities are shown in the table below:
7. Lactic acid accumulation specifically causes a
decrease in the secretion of calcium ions that
enable the coupling of the actin and myosin
protein filaments. Without sufficient calcium ions
the protein filaments cannot attach to each other.
The sliding of the protein filaments is then not
possible. LA accumulation also inhibits the action
of glycolytic enzymes that prevents glucose from
breaking down — glucose being the food fuel for
both anaerobic and aerobic glycolysis.
Hydrogen ion accumulation results in the levels
of cell pH decreasing to an extent that muscle
contraction is no longer possible, and fatigue
occurs. The low pH created by the hydrogen
ions causes the glycolytic enzymes to become
inoperative. Without the glycolytic enzymes the
breakdown of glucose cannot take place.
8. Three symptoms of dehydration are: lightheadedness/dizziness, clammy skin and profuse
sweating.
9. Urine that is stronger, and more orange than
yellow in colour, indicates dehydration. Normal
hydration urine is usually a faint yellow colour.
10. Ensure that you are well hydrated before, during
and after training. Avoid caffeine and sugar
drinks, as they induce thirst. Wear light coloured,
breathable clothing so that sweat is drawn away
from the skin, and use an ice-vest or cooling
rooms as a way of regulating body temperature
during breaks in training. Train early or late in the
day, utilising the shade as much as possible.
11. An athlete is trying to regain their pre-exercise
body condition. To do this they will have to
address the following:
• Replenishment of ATP–PC stores
• Restoration of muscle and liver glycogen stores
• Breakdown and removal of lactic acid
• Rehydration
• Repair of damaged muscle tissue.
12. Venous pooling occurs when insufficient pumping
of the muscles returns blood flow back to the
heart, causing blood to pool in the inactive
muscles of the lower extremities.
13. During the cool-down, the amount of oxygen
being consumed by the body is still well above
resting levels. This phenomenon is known as the
‘oxygen debt’ and has two distinct functions:
• To replenish muscle stores of phosphocreatine
(known as the alactacid phase of oxygen debt)
• To breakdown and remove lactic acid (known as
the lactacid phase of oxygen debt).
14. The restoration of muscle glycogen stores requires
the following essential elements:
• The greater the depletion of glycogen stores,
the faster the rate of recovery. Intake of
carbohydrate must take place within 30 minutes
407
CHAPTER 5 Fitness components,
muscles and activity analysis
AFL
Basketball
Tennis
Hockey
Volleyball
1. See the glossary on page 435 for definitions of the
key terms in this chapter.
2. (a) Anaerobic power, muscular strength (MS),
muscular power (MP), speed, agility, local
muscular endurance (LME), flexibility, and
aerobic power
(b) The table should reflect ratings similar to those
shown below:
Netball
ANSWERS TO CHAPTER REVIEW QUESTIONS
408
of cessation of activity in the amount of 1–1.5
grams of CHO per kilogram of body mass.
• High GI snacks or meals should be ingested in
either liquid or solid form.
• Supplements of protein within these meals will
also help with repair of damaged muscle tissue.
15. A combination of sweating and post-exercise
urination causes dehydration in the athlete.
16. Sports drinks do not just rehydrate, they also
replace glycogen and lost electrolytes. The sodium
contained within sports drinks also helps with
reduction of urine following exercise. However,
if fluid losses are high, sports drinks may not be
enough to both rehydrate and replace sodium
losses.
17. Discuss the various 5-step plans during class time.
Compare the plan for your chosen athlete with
those developed by other class members.
18. The banana is a high-GI food source and will
therefore be quickly digested and provide a ready
source of glucose for the player during the match.
The player should also be ingesting a sports drink that has high levels of CHO as well as the correct
balance of electrolyte supplements for this player’s individual needs.
Anaerobic power
9
10
7
8
9
7
MS
6
9
8
7
7
7
MP
8
9
9
8
7
8
Speed
8
7
6
8
8
7
Agility
8
7
7
7
7
8
LME
7
9
7
7
8
5
Flexibility
8
7
7
9
8
6
Aerobic power
9
9
8
7
9
7
Live it up 2
3. Team games have more physiological fitness
components, mainly because of the range
of movements and the higher, more varied
exertion levels. Once a range of exertion
levels is encountered within one game or
event, the lactate threshold becomes relevant
and the interplay between the anaerobic and
aerobic energy systems is central to effective
performance.
4. Flexibility is central to training sessions because
effective performance in any activity requires
the ability to perform specific movements. This
means that the required muscles and joints need
to be able to move through their full specific
ranges of movement.
5. (a) to (c) to be done by individual students and
discussed in class groups
6. Students should subjectively decide on a
performer to assess, complete the assessment and
discuss this with others in class.
7. (a) Aerobic power — because the constant and
regular exercise will sufficiently train their
cardio-circulatory respiratory systems
(b) LME — to some extent but not to a high
degree, as the posties’ LIP is unlikely to be
challenged during a day of careful riding
between letter boxes.
(Also, dynamic balance will be improved by
regular cycling.)
8. All three methods of flexibility training need to
be carried out when the individual is thoroughly
warmed up, preferably at the end of a training or
competitive session.
9. (a) Static stretching requires the individual to
assume a stretched position of the muscle and
to hold this for 10–20 seconds. This should
create a degree of discomfort, but no pain.
(b) PNF stretching can be done with a partner or
by using a fixed platform for resistance. This
method centres on assuming a comfortably
stretched position for the specific muscle,
performing a 6-second isometric contraction
of that muscle, then moving to an increased
static-stretch position. This movement may be
repeated.
10. Ballistic stretching involves carrying out a game
or activity where the muscles and joints are
moving through the specific movements needed
for competition. Three examples from three
different sports are:
• Australian Football — kicking, handball,
marking
• Netball — passing, shooting, defending
• Basketball — guarding, long passing,
dribbling.