American Council on Exercise. Group Fitness Instructor Certification Exam Review Course

Transcription

1 American Council on Exercise Group Fitness Instructor Certification Exam Review Course 1

2 About ACE ACE is dedicated to promoting physical activity and protecting consumers against unsafe and ineffective fitness products and instruction. ACE sponsors university-based exercisescience research that targets fitness products and trends. ACE is one of a small number of certifying organizations accredited by the National Organization of Certifying Agencies (NOCA). 2

3 What makes ACE different? ACE exams are legally defensible. ACE develops the study materials without using the actual exam. Rather than teaching answers to the exam, ACE prepares you to be a safe and effective group fitness instructor. 3

4 About the ACE exam How many correctly answered questions are required to pass the exam? The number will vary because each exam version has a different level of difficulty. For example, a candidate may have to answer 65% of the questions correctly on one exam version and 70% on another version. 4

5 About the ACE exam (cont.) How is the exam developed? Questions are written using the Group Fitness Instructor Exam Content Outline (ACE Group Fitness Instructor Manual, 2 nd edition Appendix B). Exam content First dimension: applied exercise science (65%) Second dimension (35%) Exercise programming and class design (49%) Group instructional methods (31%) Group leadership methods (14%) Professional responsibility (6%) 5

6 About the ACE exam (cont.) Who administers the exam? CASTLE Worldwide, Inc., an independent, professional testing company. This ensures exam security and integrity and eliminates bias. Eligibility requirements for the exam 18 years of age Current CPR certification 6

7 ACE Group Fitness Instructor Manual Chapter 1 Exercise Physiology 7

8 Fitness Being active improves health 30 minutes of accumulated physical activity on most days of the week Being fit goes beyond health and requires a comprehensive exercise program that includes the following components: Cardiorespiratory endurance Muscular strength and endurance Flexibility Body composition 8

9 Energy production ATP: the energy source used to drive muscle contraction ATP is manufactured by the mitochondria inside the muscle cell. Fatty acids and glucose are used to produce ATP. Only a small amount of amino acids are used to produce energy in a healthy person, but their use may be increased in an undernourished individual. 9

10 Structure of a Typical Cell mitochondria

11 Fuels for Exercise Carbohydrates (4 kcal/gm) Building Block: Glucose Stored as glycogen in muscle & liver Fats (9 kcal/gm) Building Block: fatty acids (& glycerol) Stored as triglycerides in adipose tissue & active cells. Proteins (4 kcal/gm) Building Block: amino acids Not a primary energy source during exercise Branched chain amino acids are used for fuel when glycogen stores are depleted

12 ENERGY TRANSFORMATIONS ATP ENERGY FROM FOOD ADP + P i ENERGY FOR WORK Supplier Intermediary Consumer -Creatine Phosphate -Carbohydrates -Fats -Proteins Biological Universal Currency ATP -Muscle Movement -Synthesis -Nerve Transmission -Etc.

13 Energy production pathways 13

14 Energy Systems for Exercise Source: Graph from Edington, D.W., and V.R. Edgerton The Biology of Physical Activity, Boston.

15 Predominant Energy Systems Duration of Event Intensity of Event Predominant Energy System(s) 0-30 sec Very Intense ATP-PC (Phosphagen) 30 sec - 3 min Heavy 3-20 min Moderate Anaerobic or Fast Glycolysis Aerobic or Slow Glycolysis 20min+ 2hr+ Low to moderate aerobic intensity Moderate to intense aerobic intensity Fat Metabolism Begins (Beta Oxidation) About 5% kcals may come from Protein

16 Contribution of Anaerobic/Aerobic

17 Metabolic equivalent (MET) A MET is the ratio of a person's working metabolic rate relative to his or her resting metabolic rate (1 MET = 3.5mL/kg/min). METs can be used to classify physical activities based on their intensities (that is, based on their requirement for oxygen consumption). A workout of 2 to 4 METs (such as bowling) is considered light, while intensive running (8 minutes per mile) or martial arts can yield 12 or more METs. Aerobic exercise machines can display METs. The numbers displayed are estimates, since the rate at which calories are burned while at rest varies from person to person. 17

18 MET calculation To determine the VO 2 equivalent of any MET value, simply multiply the MET value by 3.5. For example, a typical step aerobics class is about 7 METs Therefore, the oxygen consumption for a typical step aerobics class is: 3.5 ml/kg/min x 7 METs = 24.5 ml/kg/min 18

19 Metabolic rate Two terms are commonly used when describing metabolic rate basal metabolic rate (BMR) and resting metabolic rate (RMR). BMR is the body s minimum daily energy requirement for normal function. Typically, BMR is assessed after an overnight stay in a lab where the subject has been fasting for 12 hours and sleeping for 8 hours at a constant room temperature. BMR includes the energy used for ventilation, blood circulation, and temperature regulation. BMR is expressed in terms of daily energy requirements, or daily caloric requirements. 19

20 Metabolic rate RMR is a more common measurement than BMR. RMR can be measured with equipment that analyzes breathing gases, or it can be estimated with a mathematical equation. BMR is usually 10% lower than RMR and represents a controlled, clinically measured value. Therefore, RMR is the preferred value for field measurements such as those that are conducted in the fitness setting. RMR is also expressed in terms of daily caloric requirements. RMR typically ranges from 1,200 cal/day for women to 1,500 cal/day for men. 20

21 Metabolism and exercise Moderate aerobic exercise plus strength training increase RMR to a greater degree than aerobic exercise alone. Aerobic training increases caloric expenditure during the activity and uses body fat for fuel. Strength training may increase lean mass and cause an increase in caloric requirement by 7 10 calories per day for each additional pound of lean mass gained. Therefore, both aerobic exercise and strength training are recommended for weight management. 21

22 Metabolism and aging RMR decreases with advancing age. For each decade after age 25, 3 5% of muscle mass is lost, which negatively affects metabolic rate. Some decline still occurs in individuals who exercise regularly. However, exercise training may attenuate, or slow, the age-related declines in lean mass. 22

23 Neuromuscular anatomy Motor nerve (neuron)--conducts impulses from the central nervous system (CNS) to the periphery signaling muscles to contract or relax. 23

24 Neuromuscular anatomy cont Motor unit A motor nerve and all its associated muscle fibers All fibers comprising a motor unit are homogeneous (they are either all fasttwitch or all slow-twitch). Motor units made up of 5 10 fibers are responsible for fine, delicate movements such as blinking the eye. Motor units made up of thousands of fibers are responsible for forceful movements such as jumping. 24

25 Illustration of a Motor Unit

26 Musculoskeletal anatomy Muscle fiber A muscle cell Myofibril A contractile protein in a muscle fiber; there are many myofibrils arranged in patterns within a single muscle fiber Sarcomere The functional contracting unit of the muscle cell Myofibrils are made up of several repeating sarcomeres along the length of the muscle cell. The area between the Z-lines within a myofibril 26

27 Microstructure of Skeletal Muscle

28 Musculoskeletal anatomy Actin and myosin Contractile protein filaments within the myofibril that generate muscle contraction by sliding past one another 28

29 Musculoskeletal anatomy Connective tissue serves to connect, support, and anchor various body parts Fascia a sheet or band of fibrous tissue that lies deep to the skin or forms an attachment for muscles and organs Tendon when a muscle contracts to produce movement, it pulls on a tendon, which attaches the muscle to the bone Ligaments supportive structures found at joints that connect bones to other bones Cartilage serves as padding between the bones at a joint and functions to provide cushioning and the smooth gliding of joint movement 29

30 Muscle physiology Muscle contraction A contraction occurs when an electronic impulse is transmitted from the brain to the muscle. Muscle contraction is the result of the interaction of the actin and myosin filaments, which causes a shortening of the individual sarcomeres, and therefore, a shortening of their associated muscle fibers. 30

31 Muscle physiology Sliding filament model For muscle contraction to occur, there must be at least two factors present: Sufficient ATP A nervous impulse from the CNS When these two factors are present, tiny projections from the myosin filament attach to the actin filament forming a cross-bridge. The myosin pulls the actin toward the center of the sarcomere and the individual muscle fiber shortens. 31

32 Muscle physiology Discontinuation of a muscle contraction occurs when: Neural impulses stop Muscle fiber runs out of ATP There is a build-up of metabolic by-products, such as lactic acid Myosin and actin filaments bump up against the Z-lines and cannot contract any further 32

33 Neuromuscular physiology Muscle spindles Sensory receptors that lie parallel to the muscle fibers Respond to muscle fibers being overstretched by causing the muscle to contract Component of the stretch reflex 33

34 Neuromuscular physiology Golgi tendon organs Sensory receptors located in the muscle-tendon junction Respond to increased muscle tension by causing the muscle to relax Component of inhibition 34

35 Neuromuscular physiology All-or-none principle When a single muscle fiber contracts (or shortens), it generates its maximum force capability. When a motor unit is stimulated, all the muscle fibers it innervates contract with maximum force. The amount of force generated during a muscle group s contraction depends on the following: The size of the individual muscle fiber (the larger the fiber, the greater the force during contraction) The number of muscle fibers recruited (more fibers equal more force) The length of the muscle fiber prior to contraction ((a muscle generates maximum force when it begins its contraction at 1.2 times its resting length) The speed of contraction (the slower the movement, the more force that is produced) 35

36 Optimal force production Length-tension relationship The amount of force that a muscle can exert is related to its length. Peak force production is usually seen at resting length or slightly greater (1.2 times resting length). At approximate resting length, more of the myosin cross-bridge heads can align with active actin receptor sites. Therefore, participants with poor posture that have chronically shortened or lengthened muscle groups are not able to produce optimal force at the misaligned joints. 36

37 Optimal force production Force-velocity relationship A maximal contraction is dependent on the number of actin and myosin cross-bridges formed. The higher the speed of contraction, the lower the number of connected myosin and actin cross-bridges. An optimal speed of contraction while lifting weights appears to be a 1- to 2-second concentric action, followed by a 2- to 4-second eccentric action. 37

38 Muscle fiber types Fast-twitch (Type II) Contract rapidly Contract forcefully Fatigue quickly Primary energy system is anaerobic Used in short-term activities requiring strength and power Fast-twitch fibers are further classified into type IIa and type IIb. Type IIa fibers are slightly more oxidative than type IIb. It is possible to increase either the oxidative qualities or the glycolitic qualities of type IIa fibers through training. However, muscle fibers cannot be changed from one type to another. Slow-twitch (Type I) Contract slowly Contract less forcefully Fatigue resistant Primary energy system is aerobic Used in endurance activities 38

39 Muscle fiber types The percentage of fast-twitch versus slow-twitch fibers in each muscle is genetically determined and varies from one individual to another. One athlete might have a high percentage of fast-twitch fibers in his quadriceps, whereas his teammate might have a lower percentage. These differences influence a person s ability to successfully perform speed and power events versus endurance events. Different fiber types are recruited for different activities. Fast-twitch fibers are used in short-term activities requiring strength and power such as weightlifting and sprinting. Slow-twitch fibers are used in endurance activities such as running and swimming. 39

40 Types of muscular contraction Concentric = muscle develops tension while shortening. E.g. lifting a weight against gravity. Eccentric = muscle develops tension as it lengthens. E.g. lowering a weight against gravity in a controlled manner. Isometric = Muscle develops tension while maintaining the same length. E.g. Plank. Isokinetic =Muscle develops tension while going the same speed. E.g. hydraulic machines, swimming. 40

41 Muscular training Muscular strength = how much Hypertrophy-increase in size High-intensity resistance (80-90% 1RM), low-repetition training. Avoid Valsalva maneuver with proper breathing. Atrophy-decrease in size (use it or lose it) Muscular endurance = how long or how many Moderate intensity resistance (40-70%1RM), high-repetition training Increases blood flow to muscle (vascularity) 41

42 Muscular training Flexibility = Range of Motion (ROM) Stretching should be performed after warm-up when muscles are more warmer and more elastic. Stretching should be done to the point of mild discomfort only, to avoid DOMS Types of Stretching Static holding sec. Ballistic characterized by bobbing or bouncing (to be discouraged) Dynamic often seen as the same as ballistic, but involves moving through a range of motion. PNF (Proprioceptive Neuromuscular Facilitation)-- characterized by contract-relax. Generally requires a partner. 42

43 DOMS Delayed onset muscle soreness Peaks hours after exercising for the first time in awhile or doing something new. Exacerbated by eccentric contractions and overstretching. It does go away in a few days. Chapter 11 - Injury Prevention & Emergency Procedures 43

44 Neuromuscular adaptations to regular resistance training Neural adaptations Improved motor unit recruitment patterns Improved motor learning Neural adaptations are responsible for gains in strength with little or no change in muscle cross-sectional area after as few as 6 weeks of training. Hypertrophy of fast-twitch fibers Increased size and number of actin and myosin filaments Increased lean body mass Increased connective tissue strength Decreased risk of joint injury Increased bone mineral density 44

45 Components of the cardiorespiratory system Blood Vessels Heart Lungs Airways 45

46 Components of the cardiorespiratory system Blood: carries nutrients, gases, wastes, and hormones Nutrients carbohydrates, fats, and proteins Gases oxygen and carbon dioxide (carried in red blood cells on the protein hemoglobin) Wastes lactic acid and other metabolic by-products Hormones sympathetic and parasympathetic nervous system activation 46

47 Components of the cardiorespiratory system Vessels: transport system for blood throughout the body Arteries carry oxygenated blood away from the heart (with the exception of the pulmonary artery) Veins carry de-oxygenated blood to the heart (with the exception of the pulmonary vein) Capillaries tiny vessels across which the exchange of gases, nutrients, and wastes occurs between the blood and the cells of the body 47

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49 Arterial Blood Pressure Expressed as systolic/diastolic Normal is 120/80 mmhg High is 140/90 mmhg Systolic pressure (top number) Pressure generated during ventricular contraction (systole) Diastolic pressure Pressure in the arteries during cardiac relaxation (diastole)

50 Measurement of Blood Pressure

51 Blood Pressure throughout circulatory system

52 Arteries & Veins

53 The Skeletal Muscle Pump Rhythmic skeletal muscle contractions force blood in the extremities toward the heart One-way valves in veins prevent backflow of blood

54 Components of the cardiorespiratory system Heart: a four-chambered pump responsible for distributing blood to the lungs and to the rest of the body Right side receives venous blood returning from the body Left side receives arterial blood returning from the lungs 54

55 Components of the cardiorespiratory system Heart Atria the two upper chambers of the heart Ventricles the two lower chambers of the heart 55

56 Components of the cardiorespiratory system Heart--Blood distribution The left and right sides of the heart contract simultaneously. At the same time the blood from the right ventricle is pumped to the lungs through the pulmonary arteries, the blood from the left ventricle is ejected to the rest of the body through the aorta. 56

57 Heart Anatomy Figure 12.2 Copyright 2007 Lippincott Williams & Wilkins

58 Components of the cardiorespiratory system Heart Systole contraction phase of the cardiac cycle Diastole relaxation phase of the cardiac cycle During diastole, the heart muscle is supplied with oxygen through the coronary arteries. Having a high level of cardiorespiratory fitness means the heart spends more time in diastole at rest and during submaximal exercise due, in part, to a decreased resting heart rate (RHR). 58

59 Components of the cardiorespiratory system Lungs: encase the smaller branches of the trachea that allow gas exchange between the blood and the atmosphere Airways: transport system for carrying gases into and out of the body commonly referred to as the bronchial tree Alveoli microscopic ducts responsible for gas exchange in the lungs The lungs contain an estimated 300 million alveoli providing a surface area of approximately 230 square feet (the size of a tennis court). 59

60 Major Organs of the Respiratory System

61 Alveoli

62 Cardiorespiratory adaptations during acute aerobic exercise Increased heart rate (HR) Increased stroke volume (SV) SV is the amount of blood pumped from each ventricle each time the heart beats. SV is measured in milliliters (ml) per beat. 62

63 Cardiorespiratory adaptations during acute aerobic exercise Increased cardiac output Cardiac output = HR x SV A typical cardiac output at rest: 60 bpm x 70 ml/beat = 4,200 ml/min (approximately 1 gallon of blood per min) During maximum exercise, cardiac output can increase up to 4 to 7 times above resting level. 63

64 Cardiorespiratory adaptations during acute aerobic exercise Increased breathing rate Increased systolic blood pressure This increase is due to the cardiovascular system attempting to increase oxygen delivery to the working muscles. However, blood pressure greater than 250/115 mmhg is an indication to terminate exercise (hypertensive response). 64

65 Cardiorespiratory adaptations during acute aerobic exercise No change, or a slight decrease, in diastolic blood pressure This is due to the dilation of vessels in the muscles and the skin. Vasodilation decreases peripheral resistance. This is an important benefit for individuals suffering from heart disease, hypertension, diabetes, and peripheral vascular disease. 65

66 Cardiorespiratory adaptations during acute aerobic exercise Blood is shunted from the viscera to the working muscles Partly caused by the dilation of vessels that supply blood to the exercising muscles Partly caused by the constriction of vessels that supply blood to the abdominal area 66

67 Cardiorespiratory adaptations during acute aerobic exercise Increased extraction of oxygen from the blood into the working tissues An average healthy person is able to load the blood with more oxygen in the lungs than he or she is able to use at the cellular level. Therefore, the more efficiently an individual can extract oxygen from the hemoglobin in the capillaries, the more physical performance improves. 67

68 Oxygen extraction Oxygen enters lungs. Oxygen loads onto hemoglobin in blood and is transported to the working muscle. Oxygen is unloaded into muscle cell. Oxygen loads is transported to mitochondria. Mitochondria grow and multiply with regular exercise to increase metabolic capacity.

69 Acute Responses to Aerobic Exercise Oxygen consumption during exercise Oxygen deficit. Steady State EPOC (excell post exercise oygen consumption. Copyright 2007 Lippincott Williams & Wilkins Figure 4.7

70 Acute Responses to Aerobic Exercise Lactate Threshold Also known as anaerobic threshold (AT). The point at which blood lactic acid suddenly rises during incremental exercise Characterized by feeling out of breath and feeling a burning sensation in the working muscles. Can be used as a marker of exercise intensity

71 Acute Responses to Aerobic Exercise Lactate threshold Values Average individuals LT 40-60% of VO 2 max Endurance trained LT>70% VO 2 max.

72 Guidelines of Improving Cardio- Respiratory endurance Four basic training variables F = frequency I = intensity T = time T = type (mode) Chapter 11 - Injury Prevention & Emergency Procedures 72

73 Guidelines of Improving Cardio-Respiratory endurance General Principles of Training Specificity the body will adapt to the specific stress introduced. Overload--Manipulating any one of the four variables will result in overload. Reversibility use it or lose it. 73

74 14 Importance of warm-up Increases blood flow to active muscles Increases blood flow to myocardium Increases the dissociation of oxyhemoglobin Earlier sweating May reduce abnormal heart rhythms Copyright 2007 Lippincott Williams & Wilkins

75 Importance of cool-down Prevents venous pooling Helps remove lactic acid Allows CV system to return to a resting state gradually.

76 Cardiorespiratory adaptations from regular aerobic training Decreased RHR With consistent exercise (as few as three months of regular aerobic training), the interior dimensions of the ventricles increase, allowing them to hold more blood. The same cardiac output can be maintained at a lower HR due to the greater SV. 76

77 Cardiorespiratory adaptations from regular aerobic training Decreased relative working heart rate Since a given intensity requires a given amount of oxygen, HR at any given intensity will be lower due to an increased SV. A trained individual will have to work at higher intensities to achieve the same HR he or she achieved prior to physical training. 77

78 Cardiorespiratory adaptations from regular aerobic training Increased VO 2 max as SV increases VO 2 max (aerobic capacity) is the total capacity to take in, transport, and use oxygen during strenuous exercise. VO 2 max depends on two factors: The delivery of oxygen to the working muscle by the blood (cardiac output) The ability to extract oxygen at the capillaries and use it in the mitochondria 78

79 Cardiorespiratory adaptations from regular aerobic training Increased oxygen extraction This results in an improved ability to remain aerobic at higher intensities. Partly due to increased capillary density Partly due to increased mitochondrial density Partly due to an increased ability to create adenosine triphosphate (ATP) 79

80 Cardiorespiratory adaptations from regular aerobic training Increased fatty acid oxidation at any submaximal intensity More glycogen is stored in trained muscles and less lactic acid is produced Increased tolerance to lactic acid produced during exercise 80

81 Hormonal response to exercise Learning activity: You will be assigned a hormone. Research and be prepared to present the following information: Where is the hormone is made in the body? What does it do (in general)? Describe its relationship to exercise. Complete the summary table as a group. 81

82 Hormonal Responses to exercise Growth hormone (GH) IGF-Insulin-like growth factors Antidiuretic Hormone (ADH) Epinephrine & Norepinephrine (catecholamines) Aldosterone Cortisol 82

83 Hormonal responses to exercise Insulin Glucagon Testosterone Estrogen 83

84 Effects of chronic stress on bodily systems Physiological system Musculoskeletal system Cardiovascular system Immune system CNS Gastrointestinal system Effects of stress Tension headache, neck and shoulder discomfort, and back pain Premature coronary artery disease (CAD), hypertension, increased platelet adhesiveness, and heart attack Suppression of T-cell function, increased vulnerability to infections, and viral illnesses Impaired memory and neural degeneration Stomach ache, nausea, constipation, and diarrhea These negative changes primarily occur due to elevated levels of stress hormones such as norepinephrine and cortisol. Exercise may help decrease stress hormone levels and alleviate these symptoms. 84

85 Heat Due to increased dilation of blood vessels near the skin, venous return and SV decrease. At any given exercise intensity, HR will be higher as the heart tries to maintain cardiac output to meet the needs of the working muscles and maintain body temperature. Producing sweat (so that it may evaporate from the skin) is the body s primary cooling mechanism. High humidity does not allow sweat to evaporate, so in hot, humid environments exercisers should be vigilant about fluid intake and preventing hyperthermia. The National Athletic Trainer s Association (2000) recommends the following fluid intakes: 2 hours prior to exercise, drink oz Every minutes during exercise, drink 7 10 oz After exercise, drink oz per lb body weight lost 85

86 Cold Exercising in the cold causes the kidneys to increase urine production, risking dehydration. Heat production during exercise is usually enough to prevent hypothermia. When exercise stops, however, the individual needs to be protected from the cold. Layers of clothing that can be taken off and put back on during an outdoor cold-environment workout give the exerciser options for maintaining body temperature. Keys to exercising in the cold are drinking plenty of fluids and dressing in layers. 86

87 Altitude The partial pressure of oxygen decreases at higher altitudes, so the body compensates by increasing HR and respiratory rate. During exercise, HR may increase up to 50% higher than normal. Individuals should decrease exercise intensity at altitude so they can complete the session without becoming exhausted. It may take up to 2 to 5 weeks for the body to acclimate to a new altitude. 87

88 Air Pollution Ozone--Decreases VO 2max and respiratory function Sulfur dioxide--causes bronchoconstriction in asthmatics Carbon monoxide--binds to hemoglobin and reduces oxygen transport Prevention of problems Check Air Quality Index (AQI) Portland/Vancouver Airshed: Reduce exposure time Exercise during least polluted part of day