75, 77, & 78: Exercise I, II, & III

Question 1

Total ATP turnover can not be directly assessed in an exercising human so a valid estimate of energy cost is usually made by measuring the oxygen _____ during the exercise, V.O2 (index of energy expenditure). This assumes that all the energy is being derived _____. At rest the average person has a Resting V.O2 of 3.5 ml/min/kg = _____ MET.

To translate VO2 to Calories you need to know the caloric equivalent of consuming 1 liter of oxygen. To determine the caloric equivalent of 1 liter of oxygen: need to know the type(s) of _____ being metabolized. The types of fuels being utilized can be determined if the Respiratory Quotient at the point in time while a person is exercising (R.Q. = _____—V stands for volume) is known.

Answer 1

Total ATP turnover can not be directly assessed in an exercising human so a valid estimate of energy cost is usually made by measuring the oxygen consumed during the exercise, V.O2 (index of energy expenditure). This assumes that all the energy is being derived aerobically. At rest the average person has a Resting V.O2 of 3.5 ml/min/kg = 1 MET.

To translate VO2 to Calories you need to know the caloric equivalent of consuming 1 liter of oxygen. To determine the caloric equivalent of 1 liter of oxygen: need to know the type(s) of fuel(s) being metabolized. The types of fuels being utilized can be determined if the Respiratory Quotient at the point in time while a person is exercising (R.Q. = VCO2/VO2—V stands for volume) is known.

Question 2

Fat is a very efficient _____ form of energy in terms of kcals/g so burning 1 gram of fat requires more energy than anything else.

Answer 2

Fat is a very efficient storage form of energy in terms of kcals/g so burning 1 gram of fat requires more energy than anything else.

Question 3

See slide 5.

Answer 3

-

Question 4

Practically, R.Q can’t be measured in vivo but can be estimated by measurements of oxygen consumption (VO2) and carbon dioxide production (VCO2) at the mouth.

RER = RQ whenever the body’s total O2 content stays _____ (usual) AND when total CO2 content stays _____ (variable depending on breathing strategies).

Answer 4

Practically, R.Q can’t be measured in vivo but can be estimated by measurements of oxygen consumption (VO2) and carbon dioxide production (VCO2) at the mouth.

RER = RQ whenever the body’s total O2 content stays constant (usual) AND when total CO2 content stays constant (variable depending on breathing strategies).

Question 5

Caloric Expenditure = _____ (L/min) x _____ (Kcals/L)

Answer 5

Caloric Expenditure = VO2 (L/min) x 5.0 (Kcals/L)

Question 6

To calculate VO2 for a person using a breathing moniter during exercise:

V-_____ x F-inspied O2 x V-expired x F-_____ O2

Answer 6

To calculate VO2 for a person using a breathing moniter during exercise:

V-inspired x F-inspied O2 x V-expired x F-expired O2

Question 7

Oxygen uptake (VO2) increases with _____ work rate. This increase does not continue indefinitely and, at some point, further increases in work rate will not elicit a further increase in VO2.

No further increase in oxygen consumption = VO2 _____, a person’s maximal ability to consume oxygen.

Steady state or horizontal line occurs when oxygen supply = _____ demand–see slide 7.

Max VO2 is considered to be the best single indicator of aerobic _____ or endurance performance as it is your max aerobic work rate–see slide 8.

Supra VO2 maximal work = _____.

Answer 7

Oxygen uptake (VO2) increases with increasing work rate. This increase does not continue indefinitely and, at some point, further increases in work rate will not elicit a further increase in VO2.

No further increase in oxygen consumption = VO2 max, a person’s maximal ability to consume oxygen.

Steady state or horizontal line occurs when oxygen supply = oxygen demand–see slide 7.

Max VO2 is considered to be the best single indicator of aerobic fitness or endurance performance as it is your max aerobic work rate–see slide 8.

Supra VO2 maximal work = anaerobic.

Question 8

Changes in respiratory parameters with increasing exercise intensity (VO2). During exercise, total minute ventilation (VE) increases _____* to the point of the ventilatory threshold & then increases out of proportion to VO2 at high work intensities in an _____ fashion due to _____ respiration (lactic acidosis stimulates hyperventilation).

The hyperventilation at higher intensities is costly but useful since hyperventilation decreases alveolar and consequently arterial _____ thus helping to manage arterial pH _____ (which decreases none-the-less due to lactic acidosis).

Note that alveolar and therefore arterial PO2 is well _____ in a healthy individual even during heavy exercise. Other ventilatory responses such as an _____ in the V/Q ratio in most alveoli also contributes to effective gas exchange during exercise. The ventilatory threshold (as % of VO2max) increases with _____ levels of aerobic fitness.

See slide 10

Answer 8

Changes in respiratory parameters with increasing exercise intensity (VO2). During exercise, total minute ventilation (VE) increases linearly* to the point of the ventilatory threshold & then increases out of proportion to VO2 at high work intensities in an exponential fashion due to anaerobic respiration (lactic acidosis stimulates hyperventilation).

The hyperventilation at higher intensities is costly but useful since hyperventilation decreases alveolar and consequently arterial PCO2 thus helping to manage arterial pH decrease (which decreases none-the-less due to lactic acidosis).

Note that alveolar and therefore arterial PO2 is well maintained in a healthy individual even during heavy exercise. Other ventilatory responses such as an increase in the V/Q ratio in most alveoli also contributes to effective gas exchange during exercise. The ventilatory threshold (as % of VO2max) increases with increasing levels of aerobic fitness.

See slide 10

Question 9

Cardiac output increases fairly _____ with increasing work intensity or VO2. Max values may average 4-5x resting (5.5 l/min).

HR increases fairly _____ with increasing VO2. Sympathetic input to the _____ node increases (and parasympathetic input decreases) commensurate with the increasing physical stress of the exercise.

Stroke volume _____ initially at mild to moderate exercise intensities and then levels off or may even decline slightly at _____ work rates. SV increases as venous return and contractility of the heart are _____.

The higher CO during exercise is distributed differently than at rest. Arterioles controlling blood flow to active skeletal muscle _____ so that these tissues may receive up to 80-85% of the total CO. Blood flow to inactive muscles and the splanchnic area decreases due to vaso _____ in those arteriolar beds.

The arterial-venous oxygen difference as a function of VO2 is shown below. The arterial-venous oxygen difference _____ with progressively increasing exercise intensity due to 1) better capillary perfusion so more O2 is _____ on arterial side and _____ on venous side 2) a decreased myocyte PO2 and 3) a _____ shift in the oxygen-hemoglobin dissociation curve which facilitates hemoglobin unloading.

See slides 11 - 16

Answer 9

Cardiac output increases fairly linearly with increasing work intensity or VO2. Max values may average 4-5x resting (5.5 l/min).

HR increases fairly linearly with increasing VO2. Sympathetic input to the SA node increases (and parasympathetic input decreases) commensurate with the increasing physical stress of the exercise.

Stroke volume increases initially at mild to moderate exercise intensities and then levels off or may even decline slightly at higher work rates. SV increases as venous return and contractility of the heart are stimulated.

The higher CO during exercise is distributed differently than at rest. Arterioles controlling blood flow to active skeletal muscle dilate so that these tissues may receive up to 80-85% of the total CO. Blood flow to inactive muscles and the splanchnic area decreases due to vasoconstriction in those arteriolar beds.

The arterial-venous oxygen difference as a function of VO2 is shown below. The arterial-venous oxygen difference widens with progressively increasing exercise intensity due to 1) better capillary perfusion so more O2 is extracted on arterial side and decreased on venous side 2) a decreased myocyte PO2 and 3) a right shift in the oxygen-hemoglobin dissociation curve which facilitates hemoglobin unloading.

See slides 11 - 16

Question 10

VO2max is limited by left _____ output (cardiac output).

“Blood doping” experiments support this contention where increasing hematocrit, _____ VO2max.

Answer 10

VO2max is limited by left ventricular output (cardiac output).

“Blood doping” experiments support this contention where increasing hematocrit, increases VO2max.

Question 11

The ability of skeletal muscle to consume oxygen and pulmonary factors usually do _____ limit VO2max.

Muscles _____ VO2 max in highly deconditioned individuals (eg. bed rested, COPD, dialysis pts).

Answer 11

The ability of skeletal muscle to consume oxygen and pulmonary factors usually do not limit VO2max.

Muscles limit VO2 max in highly deconditioned individuals (eg. bed rested, COPD, dialysis pts).

Question 12

When larger muscles like legs are being worked DBP hardly _____ or does not. SBP will _____ due to CO increase and TPR to _____. In general CO increases more than TPR decreases so MAP _____. This increases is due to an increase in systolic BP rather than DBP which is expected to remain near resting levels during exercise in a healthy individual.

When smaller muscles are worked, DBP essentialy remains same and SBP increases _____ than when larger muscles are being worked at same intensity. When arm work is performed eliciting the same VO2, the blood pressure response is _____ than with leg work. TPR increases _____ during arm exercise so MAP is higher for the same VO2.

MAP = _____

Hence, the more muscle used, the _____ the BP response will be. MAP increase more during arm work than leg work because in leg exercise there is vaso _____ in large active muscle groups and vaso _____ in small, inactive muscle groups. Hence TPR decreases substatially because vasodilation decreases reseistance.

And in arm exercise there is vaso _____ in small, active muscle groups and vaso _____ in large, inactive muscle groups. Hence TPR decreases less because there is less vasodilation due to use of smaller muscle groups.

Answer 12

When larger muscles like legs are being worked DBP hardly increases or does not. SBP will increase due to CO increase and TPR to decrease. In general CO increases more than TPR decreases so MAP rises. This increases is due to an increase in systolic BP rather than DBP which is expected to remain near resting levels during exercise in a healthy individual.

When smaller muscles are worked, DBP essentialy remains same and SBP increases more than when larger muscles are being worked at same intensity. When arm work is performed eliciting the same VO2, the blood pressure response is higher than with leg work. TPR increases more during arm exercise so MAP is higher for the same VO2.

MAP = (HR x SV) x TPR = CO x TPR

Hence, the more muscle used, the lower the BP response will be. MAP increase more during arm work than leg work because in leg exercise there is vasodilation in large active muscle groups and vasoconstriction in small, inactive muscle groups. Hence TPR decreases substatially because vasodilation decreases reseistance.

And in arm exercise there is vasodilation in small, active muscle groups and vasoconstriction in large, inactive muscle groups. Hence TPR decreases less because there is less vasodilation due to use of smaller muscle groups.

Question 13

BP increases substatially when doing _____, isometric, contractions, especially when using _____ muscle groups.

The blood pressure response depends on the type of contraction being performed because static or isometric contractions begin to occlude blood flow when the contraction exceeds more than ~30% of maximal tension. Total occlusion of blood flow occurs at approximately 70% of a maximal voluntary contraction.

MAP therefore increases as TPR _____ (occluding arterial flow). So a _____ blood pressure response occurs when dynamic exercise with large muscle group is performed. Extremely large increases in MAP are seen when _____ muscle contractions are performed with large muscle groups eg. competitive weight lifting. Valsalva maneuvers can exacerbate and _____ the blood pressure response a ton.

Isometric contractions occlude arterial flow _____ than dynamic contractions, and therefore occlude TPR more.

End lecture 1/3

Answer 13

BP increases substatially when doing static, isometric, contractions, especially when using small muscle groups.

The blood pressure response depends on the type of contraction being performed because static or isometric contractions begin to occlude blood flow when the contraction exceeds more than ~30% of maximal tension. Total occlusion of blood flow occurs at approximately 70% of a maximal voluntary contraction.

MAP therefore increases as TPR increases (occluding arterial flow). So a minimal blood pressure response occurs when dynamic exercise with large muscle group is performed. Extremely large increases in MAP are seen when static muscle contractions are performed with large muscle groups eg. competitive weight lifting. Valsalva maneuvers can exacerbate and increase the blood pressure response a ton.

Isometric contractions occlude arterial flow more than dynamic contractions, and therefore occlude TPR more.

End lecture 1/3

Question 14

_____ contractions are relax contract relax contract.

Answer 14

Dynamic contractions are relax contract relax contract.

Question 15

Muscles can generate ATP aerobically and anaerobically.

1) _____ bically (fast to turn on & high in power, but short term):
- “stored” ATP
- ADP + ADP -> ATP + AMP
- creatine phosphate (CP + ADP -> ATP + C)
- glycolysis (glycolysis has the greatest capacity of anaerobic mechanisms)
- @ the beginning of an exercise (like cycling), _____ erobic mechanisms prodominate and then later in the exercise _____ mechanisms predominate. Metabolic rates stay elevated after anaerobic exercise.
2) _____:

• _____ production mechanisms are slower to turn on and less powerful than _____ mechanisms but much greater in the capacity to sustain prolonged bouts of muscle contraction.
• carbohydrate, fatty acid and amino acid oxidation

Answer 15

Muscles can generate ATP aerobically and anaerobically.

1) Anaerobically (fast to turn on & high in power, but short term):
- “stored” ATP
- ADP + ADP -> ATP + AMP
- creatine phosphate (CP + ADP -> ATP + C)
- glycolysis (glycolysis has the greatest capacity of anaerobic mechanisms)
- @ the beginning of an exercise (like cycling), anaerobic mechanisms prodominate and then later in the exercise aerobic mechanisms predominate. Metabolic rates stay elevated after anaerobic exercise.
2) Aerobically:

• Aerobic production mechanisms are slower to turn on and less powerful than anaerobic mechanisms but much greater in the capacity to sustain prolonged bouts of muscle contraction.
• carbohydrate, fatty acid and amino acid oxidation

Question 16

_____ OBICALLY PROVIDED ATP is important:

(a) during the transition period from one level of activity to a higher level of activity.
(b) whenever exercise demands exceed the _____ threshold of the individual.

The anaerobic threshold (AT), also called the “lactate threshold,” is the exertion level between aerobic and anaerobic training. The AT is the point during exercise when your body must switch from aerobic to anaerobic _____.

Answer 16

ANAEROBICALLY PROVIDED ATP is important:

(a) during the transition period from one level of activity to a higher level of activity.
(b) whenever exercise demands exceed the anaerobic threshold of the individual.

The anaerobic threshold (AT), also called the “lactate threshold,” is the exertion level between aerobic and anaerobic training. The AT is the point during exercise when your body must switch from aerobic to anaerobic metabolism.

Question 17

AEROBICALLY PROVIDED ATP:

The relative proportion of fat and carbs oxidized can be estimated from the measured respiratory exchange ratio (RER = VCO2/ VO2). Aerobic metabolism is mostly _____ and _____ based.

The RER value during exercise depends on 1) exercise intensity, 2) prior dietary history, 3) exercise duration and 4) fitness level.

The RER increases as VO2 _____. Under steady state conditions this reflects increased _____ use. At high intensities the RER also indicates that _____ ventilation is occurring.

Answer 17

AEROBICALLY PROVIDED ATP:

The relative proportion of fat and carbs oxidized can be estimated from the measured respiratory exchange ratio (RER = VCO2/ VO2). Aerobic metabolism is mostly carb and fat based.

The RER value during exercise depends on 1) exercise intensity, 2) prior dietary history, 3) exercise duration and 4) fitness level.

The RER increases as VO2 increases. Under steady state conditions this reflects increased carb use. At high intensities the RER also indicates that hyperventilation is occurring.

Question 18

High carb diets @ any given point in an exercise the RER will be _____ (RER = VCO2/ VO2).

Low carb high fat diet will have _____ RER for @ any given point in an exercise the RER will be lower.

Normal diet is intermediate between the two. Hence dietary history determines fuel used.

As the exercise becomes prolonged, the RER _____ because muscle starts to switch over to fat & less to carb = carbohydrate sparing effect to conserve carbohydrate stores.

Answer 18

High carb diets @ any given point in an exercise the RER will be higher (RER = VCO2/ VO2).

Low carb high fat diet will have lower RER for @ any given point in an exercise the RER will be lower.

Normal diet is intermediate between the two. Hence dietary history determines fuel used.

As the exercise becomes prolonged, the RER decreases because muscle starts to switch over to fat & less to carb = carbohydrate sparing effect to conserve carbohydrate stores.

Question 19

Glucose uptake by skeletal muscle _____ during exercise despite decreased blood insulin due to enhanced insulin _____.

Arterial blood glucose is well maintained during exercise unless the exercise is performed for a long period of time (hours) without supplemental carb intake (sports drinks are good). Under these circumstances, hypoglycemia can occur and result in fatigue or an inability to continue the exercise.

The rate of glycogen utilization by skeletal muscle _____ exponentially as VO2 increases.

Glycogen depletion is severe when exercise is performed to fatigue at ~ _____% VO2max and is the major cause of fatigue (& inabilty to generate tension) at this work rate. Fatigue is likely due to other factors at different exercise intensities.

Answer 19

Glucose uptake by skeletal muscle increases during exercise despite decreased blood insulin due to enhanced insulin sensitivity.

Arterial blood glucose is well maintained during exercise unless the exercise is performed for a long period of time (hours) without supplemental carb intake (sports drinks are good). Under these circumstances, hypoglycemia can occur and result in fatigue or an inability to continue the exercise.

The rate of glycogen utilization by skeletal muscle increases exponentially as VO2 increases.

Glycogen depletion is severe when exercise is performed to fatigue at ~75% VO2max and is the major cause of fatigue (& inabilty to generate tension) at this work rate. Fatigue is likely due to other factors at different exercise intensities.

Question 20

When exercising at similar work rates, exercising skeletal muscle in trained animals (and people) takes up and oxidizes _____ free fatty acids that have been mobilized from adipose tissue to support ATP synthesis.

This _____ fat use is, in part, due to the increased circulating levels of FFA’s. The higher lactate levels in the untrained animals _____ FFA release from adipose tissue.

Thus, the RER of an untrained animal/person is _____ than that of a trained animal/person at any given exercise intensity.

Hence the RER of trained animals is _____ @ same exercise intensity.

Trained animals are deriving more of their energy from _____ oxidation during exercise due to increased lipolysis @ the same workload (carb sparing) than untrained animals.

Lactate and insulin are potent _____ of lipolysis. So in trained people, less lactate allows more fat to be broken down.

Answer 20

When exercising at similar work rates, exercising skeletal muscle in trained animals (and people) takes up and oxidizes more free fatty acids that have been mobilized from adipose tissue to support ATP synthesis.

This increased fat use is, in part, due to the increased circulating levels of FFA’s. The higher lactate levels in the untrained animals inhibit FFA release from adipose tissue.

Thus, the RER of an untrained animal/person is higher than that of a trained animal/person at any given exercise intensity.

Hence the RER of trained animals is lower @ same exercise intensity.

Trained animals are deriving more of their energy from fat oxidation during exercise due to increased lipolysis @ the same workload (carb sparing) than untrained animals.

Lactate and insulin are potent inhibitors of lipolysis. So in trained people, less lactate allows more fat to be broken down.

Question 21

VO2max _____ rapidly with bed rest and is restored with aerobic training.

Bed rest (for like a few weeks) causes a _____ in VO2max & aerobic fitness.

After long bed rest, it takes a while to be able to get back to the original level of fitness. Know that VO2max, levels off & does not increase indefenetly.

Answer 21

VO2max decreases rapidly with bed rest and is restored with aerobic training.

Bed rest (for like a few weeks) causes a decrease in VO2max & aerobic fitness.

After long bed rest, it takes a while to be able to get back to the original level of fitness. Know that VO2max, levels off & does not increase indefenetly.

Question 22

VO2 max is the product of maximal _____ times maximal (a-v) O2 difference. Maximal (a-v) O2 difference = Oxygen _____.

The increase in VO2 max with training is attributable to _____ in both maximal cardiac output (therefore increased O2 delivery to skeletal muscle) and _____ (a-v) O2 diff (extraction of O2 by trained muscle).

With training skeletal muscles increase the amount of O2 they can extract due to increased capillarization due to _____ and an increase in _____ content in skeletal muscles. These changes increase VO2 max.

There is a significant increase in maximal CO due to increased training. CO = HR x SV. The increase in maximal CO is due to an increase in maximal _____. Although max HR isn’t changed (athletes and normal people can have same HR), a trained individual will have a _____ HR and _____ SV than an untrained individual at any given level of submaximal exercise.

Trained individuals have stonger heards, larger left ventricular volume, and can eject more blood per beat.

Answer 22

VO2 max is the product of maximal CO times maximal (a-v) O2 difference. Maximal (a-v) O2 difference = Oxygen extraction.

The increase in VO2 max with training is attributable to increases in both maximal cardiac output (therefore increased O2 delivery to skeletal muscle) and increased (a-v) O2 diff (extraction of O2 by trained muscle).

With training skeletal muscles increase the amount of O2 they can extract due to increased capillarization due to angiogenisis and an increase in mitochondrial content in skeletal muscles. These changes increase VO2 max.

There is a significant increase in maximal CO due to increased training. CO = HR x SV. The increase in maximal CO is due to an increase in maximal stroke volume. Although max HR isn’t changed (athletes and normal people can have same HR), a trained individual will have a lower HR and higher SV than an untrained individual at any given level of submaximal exercise.

Trained individuals have stonger heards, larger left ventricular volume, and can eject more blood per beat.

Question 23

RATE PRESSURE PRODUCT (RPP):

RPP = \_\_\_\_\_ x \_\_\_\_\_

RPP is a non-invasive index of myocardial blood flow and therefore \_\_\_\_\_ needs.  The trained heart operates more efficiently by delivering the same cardiac output at a \_\_\_\_\_ heart rate.

RPP is _____ at any given work rate in fit versus unfit people = better functioning heart.

RPP consequences:
• heart requires less oxygen
• heart requires less blood flow
• heart operates more efficiently

Answer 23

RATE PRESSURE PRODUCT (RPP):

**think about it RATE - PRESSURE**

RPP = HR X SBP

RPP is a non-invasive index of myocardial blood flow and therefore oxygen needs.  The trained heart operates more efficiently by delivering the same cardiac output at a lower heart rate.

RPP is lower at any given work rate in fit versus unfit people = better functioning heart.

RPP consequences:
• heart requires less oxygen
• heart requires less blood flow
• heart operates more efficiently

Question 24

The trained body perceives any given work rate as _____ stressful as evidenced by lower circulating levels of catecholamines at any given VO2.

If you are more fit, the same level of exercise will take out less of your reserves that in an unfit person.

Answer 24

The trained body perceives any given work rate as less stressful as evidenced by lower circulating levels of catecholamines at any given VO2.

If you are more fit, the same level of exercise will take out less of your reserves that in an unfit person.

Question 25

MUSCLE ADAPTATIONS TO AEROBIC EXERCISE

• Aerobically trained muscle displays an _____ mitochondrial content and, thus, an _____ capacity to synthesize ATP aerobically especially from free fatty acids.
• All muscle fiber types can increase mitochondrial content if used and stressed appropriately during the training program.
• The increase in mitochondrial content is associated with a marked improvement in endurance capacity (the ability to work at a high percent of VO2max for a prolonged period of time) and a greater reliance on _____ as a metabolic fuel at any given work rate.

With long term training, VO2max may _____ further increase but the ability to sustain a progressively higher % of VO2max does, resulting in improved endurance performance.

Answer 25

MUSCLE ADAPTATIONS TO AEROBIC EXERCISE

• Aerobically trained muscle displays an increased mitochondrial content and, thus, an increased capacity to synthesize ATP aerobically especially from free fatty acids.
• All muscle fiber types can increase mitochondrial content if used and stressed appropriately during the training program.
• The increase in mitochondrial content is associated with a marked improvement in endurance capacity (the ability to work at a high percent of VO2max for a prolonged period of time) and a greater reliance on fat as a metabolic fuel at any given work rate.

With long term training, VO2max may not further increase but the ability to sustain a progressively higher % of VO2max does, resulting in improved endurance performance.

Question 26

Psychologically, trained individuals also perceive exercise at any given VO2 as _____ stressful. They will report a lower number on any of the many types of perceived exertion scales. The scale depicted above is the Borg 15 point scale where a “6” represents no feelings of exertion or effort at all and a 20 represents supramaximal exertion.

Answer 26

Psychologically, trained individuals also perceive exercise at any given VO2 as less stressful. They will report a lower number on any of the many types of perceived exertion scales. The scale depicted above is the Borg 15 point scale where a “6” represents no feelings of exertion or effort at all and a 20 represents supramaximal exertion.

Question 27

Exercise to improve cardiorespiratory fitness:

• Dynamic activity using _____ muscle groups is best. Examples of appropriate activities include, walking briskly, swimming cycling, running etc. It is much easier to _____ a satisfying level of fitness than to develop it from a poor fitness level.
• Exercise 3x per week (minimum) to 5x per week for 20 to 60 minutes (excluding warm-up and cool-down).
• Intensity of 55% to 75% VO2max (70% to 85% max HR or 11 to 15 on the 15 point RPE scale). May be 40% to 50% VO2max (50% TO 65% MAX HR) for very deconditioned individuals
• Apply overload principle. The overload principle means that in order to improve, body systems must be exposed to sufficient _____. As training adaptations occur, the exercise stress must _____ in order to continue to provide an adequate stimulus for adaptation.

End lecture 2/3

Answer 27

Exercise to improve cardiorespiratory fitness:

• Dynamic activity using large muscle groups is best. Examples of appropriate activities include, walking briskly, swimming cycling, running etc. It is much easier to maintain a satisfying level of fitness than to develop it from a poor fitness level.
• Exercise 3x per week (minimum) to 5x per week for 20 to 60 minutes (excluding warm-up and cool-down).
• Intensity of 55% to 75% VO2max (70% to 85% max HR or 11 to 15 on the 15 point RPE scale). May be 40% to 50% VO2max (50% TO 65% MAX HR) for very deconditioned individuals
• Apply overload principle. The overload principle means that in order to improve, body systems must be exposed to sufficient stress. As training adaptations occur, the exercise stress must increase in order to continue to provide an adequate stimulus for adaptation.

Question 28

Stronger muscles can maximally generate _____ force and power and do more work. More importantly, any given amount of force or power generated or work done can be achieved at a lower recruitment level thus reducing fatigue with repeated contractions.

These factors favorably impact:

• balance and fall prevention
• ability to perform ADL’s
• performance in most athletic endeavors
• bone mineral density

Answer 28

Stronger muscles can maximally generate more force and power and do more work. More importantly, any given amount of force or power generated or work done can be achieved at a lower recruitment level thus reducing fatigue with repeated contractions.

These factors favorably impact:

• balance and fall prevention
• ability to perform ADL’s
• performance in most athletic endeavors
• bone mineral density

Question 29

Muscle strength depends on:

A. _____ Properties:
• muscle size (bigger = stronger)
• muscle length
• velocity of contraction

B. _____ Properties:
• recruitment level
• frequency of firing of motor units

Answer 29

Muscle strength depends on:

A. Muscle Properties:
• muscle size (bigger = stronger)
• muscle length
• velocity of contraction

B. Neural Properties:
• recruitment level
• frequency of firing of motor units

Question 30

With resistance training, initial strength gains are primarily due to _____ mechanisms and later gains due to _____ (increased actin and myosin content). Genetic limitations can be stretched by the use of anabolic steroids.

Hyperplasia is _____ a usual mechanism by which an increase in strength occurs in response to strength training. _____ and loss of strength occurs with disuse and can be alarmingly rapid especially with immobilization or complete bed rest.

Answer 30

With resistance training, initial strength gains are primarily due to neural mechanisms and later gains due to hypertrophy (increased actin and myosin content). Genetic limitations can be stretched by the use of anabolic steroids.

Hyperplasia is not a usual mechanism by which an increase in strength occurs in response to strength training. Atrophy and loss of strength occurs with disuse and can be alarmingly rapid especially with immobilization or complete bed rest.

Question 31

To increase muscle strength:

1. Consider exercises for _____ muscle groups of the UE, LE and trunk (8 to 10 exercises)
2. Choose weight that can be lifted 8-12 times to fatigue (~60 - 80% of a 1-RM), 1 - 3 sets, 2 - 3 times per week. 1 time per week may be _____ for maintenance. Employ overload principles.

• since there is a large neural component to strength training it is a good idea to use a _____ of exercises for any given muscle group
• exercise to _____ ensures that the motor units that are most difficult to recruit but with the most potential for hypertrophy are used. However it is a good idea to start out with a less than maximal effort in order to learn to do the exercises properly and to avoid severe DOMS (delayed onset muscle soreness).
• performing _____ good set per session has been shown to provide about 80% of the gains as compared to 3 sets
• research indicates that 24-48 hours should _____ between strength training sessions for any given muscle group
• this prescription can be modified depending on the specific goals (eg. muscle power, hypertrophy, endurance)

Answer 31

To increase muscle strength:

1. Consider exercises for major muscle groups of the UE, LE and trunk (8 to 10 exercises)
2. Choose weight that can be lifted 8-12 times to fatigue (~60 - 80% of a 1-RM), 1 - 3 sets, 2 - 3 times per week. 1 time per week may be sufficient for maintenance. Employ overload principles.

• since there is a large neural component to strength training it is a good idea to use a variety of exercises for any given muscle group
• exercise to fatigue ensures that the motor units that are most difficult to recruit but with the most potential for hypertrophy are used. However it is a good idea to start out with a less than maximal effort in order to learn to do the exercises properly and to avoid severe DOMS (delayed onset muscle soreness).
• performing 1 good set per session has been shown to provide about 80% of the gains as compared to 3 sets
• research indicates that 24-48 hours should elapse between strength training sessions for any given muscle group
• this prescription can be modified depending on the specific goals (eg. muscle power, hypertrophy, endurance)

Question 32

HEALTH IMPLICATIONS OF EXERCISE

1. Enhanced sense of well-being.
2. Retards loss of work capacity and strength that occur with age.
3. Better able to _____ STRESS:

A. Generally, any given physical activity represents a lower % of the maximum that can be done and, therefore, is less stressful.

B. _____ cardiac efficiency: the Rate-Pressure Product (RPP) which equals HR x SBP is a reasonable, non-invasive index of myocardial oxygen need. A trained person accomplishes any given cardiac output with a _____ HR and _____ SV thus diminishing the energy demands of the heart at any given work rate.

4. Helps prevent and/or reverse risk factors associated with many chronic diseases prevalent in the general population especially _____.

Answer 32

HEALTH IMPLICATIONS OF EXERCISE

1. Enhanced sense of well-being.
2. Retards loss of work capacity and strength that occur with age.
3. Better able to accommodate STRESS:

A. Generally, any given physical activity represents a lower % of the maximum that can be done and, therefore, is less stressful.

B. Greater cardiac efficiency: the Rate-Pressure Product (RPP) which equals HR x SBP is a reasonable, non-invasive index of myocardial oxygen need. A trained person accomplishes any given cardiac output with a lower HR and higher SV thus diminishing the energy demands of the heart at any given work rate.

4. Helps prevent and/or reverse risk factors associated with many chronic diseases prevalent in the general population especially CHD.

Question 33

Regular physical activity is _____ associated with:

Cardiovascular disease:
• coronary artery disease
• stroke
• peripheral vascular disease

CV disease risk factors:
	• hypertension
	• high TG and low HDL cholesterol
	• platelet adhesiveness and aggregation
	• insulin needs and glucose intolerance

Some cancers:
• colon
• reproductive (especially female)

Overweight and obesity

Type 2 diabetes mellitus

Osteoporosis

Anxiety and depression

Dementia generally and Alzheimer’s specifically

Answer 33

Regular physical activity is inversely associated with:

Cardiovascular disease:
• coronary artery disease
• stroke
• peripheral vascular disease

CV disease risk factors:
	• hypertension
	• high TG and low HDL cholesterol
	• platelet adhesiveness and aggregation
	• insulin needs and glucose intolerance

Some cancers:
• colon
• reproductive (especially female)

Overweight and obesity

Type 2 diabetes mellitus

Osteoporosis

Anxiety and depression

Dementia generally and Alzheimer’s specifically

Question 34

Even for individuals with existing health risk factors, those with the highest levels of physical activity (>8 METS) have _____ longevity as compared to those with the lowest levels of activity (

Answer 34

Even for individuals with existing health risk factors, those with the highest levels of physical activity (>8 METS) have greater longevity as compared to those with the lowest levels of activity (

Question 35

Exercise and Cardiovascular Disease:

4 main risk factors:
• smoking
• \_\_\_\_\_ lipidemia
• \_\_\_\_\_ tension
• \_\_\_\_\_ behavior

Answer 35

Exercise and Cardiovascular Disease:

4 main risk factors:
• smoking
• hyperlipidemia
• hypertension
• sedentary behavior

Question 36

Regular physical activity _____ total serum triglycerides. This effect is especially evident in those with the highest TG’s to begin with. Another positive effect of exercise is an _____ in circulating HDL’s and thus a more favorable HDL/LDL ratio. Total serum cholesterol may be less significantly impacted.

In other words, exercise _____ hypertension.

Answer 36

Regular physical activity decreases total serum triglycerides. This effect is especially evident in those with the highest TG’s to begin with. Another positive effect of exercise is an increase in circulating HDL’s and thus a more favorable HDL/LDL ratio. Total serum cholesterol may be less significantly impacted.

In other words, exercise decreases hypertension.

Question 37

Regular exercise has a small but potentially important effect of _____ blood pressure (both systolic and diastolic) in normotensive individuals.

Severely hypertensive people usually need a pharmacologic _____ and should exercise cautiously preferably with medical guidance. Exercise seems to benefit those with _____ hypertension the most and may obviate (remove) the need for drug therapy.

Answer 37

Regular exercise has a small but potentially important effect of lowering blood pressure (both systolic and diastolic) in normotensive individuals.

Severely hypertensive people usually need a pharmacologic intervention and should exercise cautiously preferably with medical guidance. Exercise seems to benefit those with borderline hypertension the most and may obviate (remove) the need for drug therapy.

Question 38

The higher the physical fitness OR physical activity level, the greater the _____ in relative risk for both coronary artery disease specifically and all cardiovascular disease in general.

Answer 38

The higher the physical fitness OR physical activity level, the greater the reduction in relative risk for both coronary artery disease specifically and all cardiovascular disease in general.

Question 39

Role of exercise:

• expends calories during and _____ exercise
• better match of calorie intake and expenditure = people modify their food intake to not exceed expenditure
• maintains LBM (lean body mass) and so prevents _____ in BMR with weight loss

Although in the short term, the caloric expenditure during exercise is not great relative to the energy potential of adipose tissue stores (~3,500 kcals/lb), chronic physical activity in the _____ term serves to promote healthy weight loss.

Excess mortality _____ with increasing BMI.

Answer 39

Role of exercise:

• expends calories during and after exercise
• better match of calorie intake and expenditure = people modify their food intake to not exceed expenditure
• maintains LBM (lean body mass) and so prevents decrease in BMR with weight loss

Although in the short term, the caloric expenditure during exercise is not great relative to the energy potential of adipose tissue stores (~3,500 kcals/lb), chronic physical activity in the long term serves to promote healthy weight loss.

Excess mortality increases with increasing BMI.

Question 40

The best prescription to overweight patients is exercise + ____ restrictions.

Answer 40

The best prescription to overweight patients is exercise + dietary restrictions.

Question 41

Reccomendations:

• aim for a 500 Kcal/day deficit

• 250 Kcals _____ intake
• 250 Kcals _____ activity
• obese will need _____ calorie restriction and greater calorie expenditure
• avoid sudden, large decreases in caloric intake
• include _____ exercises to maintain LBM
• expect pattern of fat loss to _____ pattern of fat gain
• remember small things add up over time
• a _____ of 30 minutes of moderate physical activity, 5 days per week or a minimum of 20 minutes of _____ activity, 3 days per week
• _____ of moderate and vigorous activity can be performed to meet this recommendation
• alternatively accumulate 150 minutes of exercise/week
• may be broken down into 3 x 10 minute sessions/day
• 200-250 minutes/week when weight loss is a major goal
• moderate intensity can be 50%VO2 max for healthy adults or as low as 40% VO2 max in patients with low fitness
• include moderately intense resistance training for major muscle groups
• recognize the dose-response relation between physical activity and health = more exercise gives better health
• Patients are often on information overload when talking to a physician so _____ information which can be reviewed more leisurely is beneficial.

Answer 41

Reccomendations:

• aim for a 500 Kcal/day deficit

• 250 Kcals decreased intake
• 250 Kcals increased activity
• obese will need greater calorie restriction and greater calorie expenditure
• avoid sudden, large decreases in caloric intake
• include resistance exercises to maintain LBM
• expect pattern of fat loss to mirror pattern of fat gain
• remember small things add up over time
• a minimum of 30 minutes of moderate physical activity, 5 days per week or a minimum of 20 minutes of vigorous activity, 3 days per week
• combinations of moderate and vigorous activity can be performed to meet this recommendation
• alternatively accumulate 150 minutes of exercise/week
• may be broken down into 3 x 10 minute sessions/day
• 200-250 minutes/week when weight loss is a major goal
• moderate intensity can be 50%VO2 max for healthy adults or as low as 40% VO2 max in patients with low fitness
• include moderately intense resistance training for major muscle groups
• recognize the dose-response relation between physical activity and health = more exercise gives better health
• Patients are often on information overload when talking to a physician so written information which can be reviewed more leisurely is beneficial.

Question 42

A 50 kg woman is exercising at 10 METS. The approximate caloric expenditure of this woman in Kcals/min is:

Answer 42

(10 METS x 3.5 mlO2/min/kg x 50kg x 5Kcals/LO2) / 1000 = 8.75 Kcals/min

Question 43

The 15 fold increase in VO2 which can be seen as fit individual progresses from rest to intense exercise is most likely attributable to a:

Answer 43

5 fold increase in cardiac output and a 3 fold increase in oxygen extraction.