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The worksheet atached in the 1 file below , Dont use chat gpt and any plagiarism and take all the info from powerpoints This assignment is designed to guide learners through important concepts such as energy expenditure, oxygen consumption, exercise intensity and duration effects, causes of fatigue, and prevention strategies for DOMS and cramps. The chapter in powerpoint with all the info is bellow in files :
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SES 3033 Physiology of Exercise
Energy Expenditure and Fatigue Worksheet
Objectives:
1. Identify and describe methods used to measure energy expenditure.
2. Identify energy expenditure characteristics that contribute to exercise performance.
3. Differentiate between fatigue, muscle soreness, and cramps.
Briefly define/describe the following terms in your own words (0.5 points each):
1. Indirect calorimetry:
2. VO2:
3. VCO2:
4. Respiratory exchange ratio:
5. Resting metabolic rate:
6. Maximal oxygen uptake:
7. Oxygen deficit:
8. Excess postexercise oxygen consumption:
9. Lactate threshold:
10. Critical Power:
11. Delayed onset muscle soreness:
12. Exercise-associated muscle cramps:
Continue to the next page.
SES 3033 Physiology of Exercise
Use your textbook and Figure 5.3 (below) to answer questions 1-6. Be detailed in your
answers.
The figure above shows oxygen uptake (VO2) in absolute terms (L/min) on the vertical axis. Exercise power output (intensity) is
shown in watts (W) on a cycle ergometer. Lastly, blood lactate is shown on the right-hand vertical axis.
1.5 Points Each
1. Look at the right-hand graph, provide a physiological explanation as to why VO2 increases linearly as
exercise intensity increases. What is happening near the top right corner of this graph (red
segment)? What does this signify?
2. Look at the left-hand graph and inspect each line. You should notice a sharp increase in VO2 and
then a plateau after 1-3 minutes. What does the sharp increase and then plateau signify?
3. Does the plateau occur at the same time-point for each line? If not, use a physiologic approach to
describe why this does not occur. If yes, then explain using a physiologic approach as well.
4. You should see a dotted line showing blood lactate (lactic acid) concentrations as intensity
increases. Describe the shape of this line and then provide a physiologic explanation for the shape of
this line. What does this mean in relation to exercise performance?
5. Let’s say the figure above was of a trained person and then we included a new figure of an untrained
person. What would be different when comparing the trained person to the untrained person?
6. Based on this figure and the previous questions, what would you say is important regarding success
in aerobic performances?
SES 3033 Physiology of Exercise
Use your textbook and Figure 5.5 (below) to answer questions 5-9. Be detailed in your
answers.
7. Let’s say the oxygen requirement in the figure is about 2.0 L/min. What would happen to the oxygen
deficit, time in oxygen deficit, EPOC, and time in EPOC if the oxygen requirement was increased to
3.5 L/min?
8. Do you think there is ever a time where the oxygen deficit will continue until exercise is ceased, or
will an individual always reach a steady state?
2 Points
9. There are quite a few potential causes of fatigue and cramps as it relates to exercise. Two main
divisions of fatigue are peripheral and central mechanisms. Explain what is meant by “peripheral”
mechanisms and “central” mechanisms. Then provide an example of when peripheral fatigue may
occur and an example of when central fatigue may occur. Could any of these be related to cramps as
well?
10. Delayed-onset muscle soreness is a potential barrier to exercise, especially for beginners. Cramps
may also occur in this population as well. How could one prevent or reduce the effects of DOMS and
cramps so that these barriers to exercise are reduced? Provide at least two examples for each.
Energy Expenditure
CHAPTER 5 Overview
• Measuring energy expenditure
• Estimating energy expenditure
• Predicting energy expenditure
• Energy expenditure at rest and during
exercise
Measuring Energy Expenditure:
Direct Calorimetry (1 of 2)
• Substrate metabolism efficiency
– 40% of substrate energy → ATP
– 60% of substrate energy → heat
• Heat production increases with energy
production.
– Can be measured in a calorimeter.
– Water flows through walls.
– Body temperature increases water temperature.
(continued)
Measuring Energy Expenditure:
Direct Calorimetry (2 of 2)
• Pros
– Accurate over time
– Good for resting metabolic measurements
• Cons
– Expensive, slow
– Heat added by exercise equipment
– Measurement errors created by sweat
– Neither practical nor accurate for exercise
Figure 5.1
Measuring Energy Expenditure:
Indirect Calorimetry
• Estimates total body energy expenditure
based on O2 used and CO2 produced.
– Measures respiratory gas concentrations.
– Is accurate only for steady-state oxidative
metabolism.
• Older methods of analysis are accurate but
slow.
• New methods are faster but expensive.
Measuring Energy Expenditure:
O2 and CO2 Measurements
•
• VO2: volume of O2 consumed per minute
– Rate of O2 consumption
– Volume of inspired O2 − volume of expired O2
•
• VCO2: volume of CO2 produced per minute
– Rate of CO2 production
– Volume of expired CO2 − volume of inspired CO2
Figure 5.2
Measuring Energy Expenditure:
Haldane Transformation
•
•
• V of inspired O2 may not = V of expired CO2
•
•
• V of inspired N2 = V of expired N2
• Haldane transformation
•
– Allows V of inspired air (unknown) to be directly
•
calculated from V of expired air (known)
– Is based on constancy of N2 volumes
•
•
– VI = (VE x FEN2)/FIN2
•
•
– VO2 = (VE) x {[1-(FEO2 + FECO2) x (0.265)] − (FEO2)}
Measuring Energy Expenditure:
Respiratory Exchange Ratio (1 of 2)
• O2 usage during metabolism depends on
the type of fuel being oxidized.
– More carbon atoms in molecule = more O2 needed
– Glucose (C6H12O6) < palmitic acid (C16H32O2)
• Respiratory exchange ratio (RER)
– Ratio between rates of CO2 production, O2 usage
•
•
– RER = VCO2/VO2
(continued)
Measuring Energy Expenditure:
Respiratory Exchange Ratio (2 of 2)
• RER for 1 molecule glucose = 1.0
– 6 O2 + C6H12O6 → 6 CO2 + 6 H2O + 32 ATP
•
•
– RER = VCO2/VO2 = 6 CO2/6 O2 = 1.0
• RER for 1 molecule palmitic acid = 0.70
– 23 O2 + C16H32O2 → 16 CO2 + 16 H2O + 129 ATP
•
•
– RER = VCO2/VO2 = 16 CO2/23 O2 = 0.70
• Predicts substrate use, kilocalories/O2
efficiency
Table 5.1 Respiratory Exchange Ratio (RER) as a
Function of Energy Derived From Various Fuel Mixtures
% Kcal from
carbohydrates
% Kcal from
fats
RER
Energy
(kcal/L O2)
0
100
0.71
4.69
16
84
0.75
4.74
33
67
0.80
4.80
51
49
0.85
4.86
68
32
0.90
4.92
84
16
0.95
4.99
100
0
1.00
5.05
Measuring Energy Expenditure:
Indirect Calorimetry Limitations
• CO2 production may not = CO2 exhalation.
• RER is inaccurate for protein oxidation.
• RER near 1.0 may be inaccurate when
lactate buildup CO2 exhalation.
• Gluconeogenesis produces RER O2 consumed in early exercise
– Thus, body incurs O2 deficit.
– Occurs when anaerobic pathways are used for ATP
production.
• O2 consumed > O2 demand in early recovery
– Excess postexercise O2 consumption (EPOC)
– Replenishes ATP/PCr stores, converts lactate to
glycogen, replenishes hemo/myoglobin, clears CO2
Figure 5.5
Animation 5.5
For audio description use this link:
https://players.brightcove.net/901973548001/kplGlX8REA_default/index.html?videoI
d=6263541563001
Anaerobic Energy Expenditure:
Lactate Threshold (1 of 2)
• Lactate threshold: point at which blood
lactate accumulation increases markedly
– Lactate production rate > lactate clearance rate
– Interaction of aerobic and anaerobic systems
– Good indicator of potential for endurance exercise
•
• Usually expressed as percentage of VO2max
(continued)
Anaerobic Energy Expenditure:
Lactate Threshold (2 of 2)
• Higher lactate threshold = better endurance
performance.
•
• For two athletes with same VO2max, higher
lactate threshold predicts better
performance.
Figure 5.6
Energy Expenditure During Exercise:
Economy of Effort
• As athletes become more skilled, they use
less energy for a given pace.
•
– Is truly independent of VO2max.
– Body learns energy economy with practice.
• Multifactorial phenomenon
– Economy increases with distance of race.
– Practice lends better economy of movement (form).
– Varies with type of exercise (running vs. swimming).
Figure 5.7
Energy Expenditure:
Successful Endurance Athletes
•
1. High VO2max
•
2. High lactate threshold (as % VO2max)
3. High economy of effort
4. High percentage of type I muscle fibers
Energy Expenditure:
Energy Cost of Various Activities
• Varies with type and intensity of activity.
•
• Is calculated from VO2, expressed in
kilocalories/minute.
• Values ignore anaerobic aspects, EPOC.
• Daily expenditures depend on
– activity level (largest influence) and
– inherent body factors (age, sex, size, weight, FFM).
Fatigue, Muscle Soreness,
and Muscle Cramps
CHAPTER 6 Overview
• Fatigue and its causes
• Critical power: the link between energy
expenditure and fatigue
• Muscle soreness
• Exercise-induced muscle cramps
Fatigue and Its Causes (1 of 2)
• Two definitions of fatigue
– Decrements in muscular performance with continued
effort, accompanied by sensations of tiredness
– Inability to maintain required power output to
continue muscular work at given intensity
• Reversible by rest
(continued)
Fatigue and Its Causes (2 of 2)
• Complex phenomenon
– Type, intensity of exercise
– Muscle fiber type
– Training status, diet
• Four major causes (synergistic?)
– Inadequate energy delivery/metabolism
– Accumulation of metabolic by-products
– Failure of muscle contractile mechanism
– Altered neural control of muscle contraction
Fatigue and Its Causes:
Energy Systems—PCr Depletion
• PCr depletion coincides with fatigue.
– PCr is used for short-term, high-intensity effort.
– PCr gets depleted more quickly than total ATP.
• Pi accumulation may be potential cause.
• Pacing helps defer PCr depletion.
Fatigue and Its Causes: Energy
Systems—Glycogen Depletion (1 of 3)
• Glycogen reserves are limited and get
depleted quickly.
• Depletion is correlated with fatigue.
– Related to total glycogen depletion
– Unrelated to rate of glycogen depletion
• Depleted more quickly with high intensity.
• Depleted more quickly during first few
minutes of exercise.
(continued)
Fatigue and Its Causes: Energy
Systems—Glycogen Depletion (2 of 3)
• Fiber type and recruitment patterns
– Fibers recruited first or most often get depleted fastest.
– Type I fibers get depleted after moderate endurance
exercise.
• Recruitment dependent on exercise intensity
– Type I fibers recruited first (light/moderate intensity)
– Type IIa fibers recruited next (moderate/high intensity)
– Type IIx fibers recruited last (maximal intensity)
(continued)
Fatigue and Its Causes: Energy
Systems—Glycogen Depletion (3 of 3)
• Depletion in different muscle groups
– Activity-specific muscles are depleted fastest.
– Are recruited earliest and longest for given task.
• Depletion and blood glucose
– Muscle glycogen insufficient for prolonged exercise
– Liver glycogen → glucose into blood
– As muscle glycogen , liver glycogenolysis
– Muscle glycogen depletion + hypoglycemia = fatigue
Figure 6.2a
Figure 6.2b
Figure 6.3a
Figure 6.3b
Figure 6.4
Fatigue and Its Causes:
Metabolic By-Products (1 of 3)
• Pi: from rapid breakdown of PCr, ATP
• Heat: retained by body, core temperature
• Lactic acid: product of anaerobic glycolysis
• H+ accumulation: causes muscle acidosis
– H+ + lactic acid → lactate + H+
(continued)
Fatigue and Its Causes:
Metabolic By-Products (2 of 3)
• Lactic acid accumulates during brief, highintensity exercise.
– If not cleared immediately, converts to lactate + H+.
– H+ accumulation causes muscle pH (acidosis).
• Buffers help muscle pH but not enough.
– Buffers minimize drop in pH (7.1 to 6.5, not to 1.5).
– Cells, therefore, survive but don’t function well.
– If pH
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