NASM Personal Fitness Training

Certified Personal Trainer Exam

Chapter 1

The Scientific Rationale for Integrated Training

The Rise of Chronic Disease

• Chronic disease is define as an incurable illness or health condition that persists for a year or more

• Obesity: BMI of 30 or greater, at least 30 pounds over recommended weight for their height– Appx 34 percent of americans are obese (72 million!)

• Chronic disease is defined as an incurable illness or health condition that persists for a year or more

The Rise of Chronic Disease• Obesity:

– Being considerably overweight– BMI of 30 or greater– Is at least 30 pounds heavier than recommended weight for

their height• Overweight:

– BMI of 25-29.9– Between 25-30 pounds over recommended weight for their

height• Associated with risk of cardiovascular disease, type 2 diabetes, high

cholesterol, osteoarthritis, cancer, pregnancy complications, shortened life expetency, decreased quality of life

The Rise of Chronic Disease

• Blood Lipids– A.k.a. cholesterol and triglycerides– Carried in bloodstream by protein molecules HDL (high-

density lipoproteins) or “good cholesterol– Also carried by LDL (low-density lipoproteins)– Total healthy cholesterol is less than 200mg/dL– Borderline high cholesterol is between 200-239 mg/dL– High-risk level is more than 240 mg/dL– 50% of adults have total cholesterol values of 200

mg/dL or higher

The Rise of Chronic Disease• Diabetes Mellitus affects nearly 23 million Americans• Condition in which blood glucose is unable to enter cells either

because the pancreas is unable to produce insulin or the cells have become insulin resistant.

• Type I, often referred to as Juvinile-onset, is a result of the pancreas not producing insulin

• Type II, is associated obesity, particularly abdominal obesity, and accounts for 90-95% of all diabetes

• If not properly managed, high blood sugar can lead to a host of problems including:– Nerve damage, vision loss kidney damage, sexual dysfunction, and

decreased immune function

Evidence of Muscular Dysfunction and Increased Injury

• Low-back pain is primary cause of musculoskeletal degeneration seen in adults– Affects nearly 80% of all adults– Predominant among workers in:• Enclosed spaces• Manual labor• Sitting for periods longer than 3 hours• Individuals with altered lumbar lordosis

Evidence of Muscular Dysfunction and Increased Injury

• Knee Injuries– Estimated 80,000-100,000 ACL injuries occur annually in the

general US population– Appx 70% of these are non-contact injuries– Most ACL injuries occur between 15 and 25 years of age

• Of work-related injuries, more than 40% are sprains and strains– More than 1/3 involve the trunk

• Of these, more than 60% involve the low back

• The monetary value of lost work time as a result of injuries was estimated to be about $120 billion.

Current Training Programs

• A proprioceptively enriched environment is one that challenges the internal balance and stabilization mechanisms in the body

• Proprioception– The cumulative sensory input to the CNS from all

mechanoreceptors that sense body position and limb movement

• Deconditioned– A state of lost physical fitness, which may include muscle

imbalances, decreased flexibility, and a lack of core and joint stability

Integrated Training and the OPT Model

• A training program that systematically progresses any client toward any goal

• Physiologic Benefits– Improves cardiorespiratory efficiency– Enhances benficial endocrine (hormone) and

serum lipid (cholesterol) adaptions– Increases metabolic efficiency (metabolism)– Increases bone density

Integrated Training and the OPT Model• Physical Benefits– Decreases body fat– Increases lean body mass– Increases tissue tensile strength

• Performance Benefits– Strength– Power– Endurance– Flexibility– Speed and agility– Balance

Phases of Training• OPT model is divided into 3 different levels of training

– Phase I: Stabilization• Endurance Training• Main focus: increase muscular endurance and stability while developing

optimal neuromuscular efficiency• Low loads, high reps

– Phase 2: Strength Endurance Training• Phase 2: Emphasis on maintaining stabilization endurance while increasing

prime mover strength• Moderate loads and reps (8-12)• Phase 3: Hypertrophy training for max muscle growth

– Phase 3: Hypertrophy Training• Goal: achieve optimal levels of muscular hypertrophy• High volume, moderate to high loads, moderate to low reps

Phases of Training• Phase 4: Max Strength Training (optional)

– Increase motor unit recruitment– Increase frequency of motor unit recruitment– Improve peak force– High Loads, low reps (1-5), longer rest periods

• Phase 5: Power Training– Enhance neuromuscular efficiency– Enhance prime mover strength– Increase rate of force production– Superset one strength and one power exercise per body part– Perform all exercises as fast as can be controlled

Chapter 2

Basic Exercise Science

Human Movement

• Human movement is accomplished through the fuctional integration of 3 systems:– Nervous– Musucular– Skeletal

• These 3 systems are also known as the Kinetic Chain

The Nervous System

• Consists of neurons that transmit and coordinate signals– Provides a network of communication within the body

• 3 Primary Functions– Sensory: ability to sense changes in internal or external

environment– Integrative: analyze and interpret sensory information– Motor: neuromuscular response to sensory

information

Anatomy of the Nervous System

• Neuron: the functional unit of the nervous system

• Consists of:– The Brain– Spinal Cord– Peripheral Ganglia

• Forms the core of the nervous system

Anatomy of the Nervous System

• Neurons composed of 3 main parts– Cell Body: Contains a nucleus and other organelles,

including:• Lysosomes• Mitochondria• A Golgi complex

– Axon: provides communication from the brain and spinal cord to other parts of the body

– Dendrites: gather information from other structures and transmit it back to the neuron

Anatomy of the Nervous System

• 3 Functional Classifications of neurons– Sensory (afferent): • respond to touch, light, and other stimuli• Transmit nerve impulses from muscles and organs to

the brain and spinal cord– Interneurons• Transmit nerve impulses from one neuron to another

– Motor (efferent)• Transmit nerve impulses from brain and spinal cord to

the effector sites such as muscles and glands.

Central and Peripheral Nervous Systems

• Central Nervous System: Consists of brain and spinal cord– Primary function is to coordinate activity of all parts of the

body• Peripheral Nervous System: consists of nerves that

connect the CNS to rest of body and external environment

• Two main functions1. Provide a connection to nervous system to activate different

effector sites2. Relay information from effector sites back to the brain

The CNS and PNS• 2 Subdivisions of the PNS

1. Somatic• Consists of nerves that serve the outer areas of the body and skeletal

muscle• Responsible for voluntary movement

2. Autonomic• Supplies neural input to involuntary systems

– Ex: heart, digestive systems, endocrine glands• Further divided into Sympathetic and Parasympathetic• Both divisions serve to increase levels of activation in preparation for

activity• Parasympathetic decreases levels of activation during rest and

recovery

The CNS and PNS

• Sensory Receptors– Convert environmental stimuli (light, heat, taste) into sensory

information for the CNS– 4 categories

1. Mechanoreceptors: – Touch and pressure– Located within muscles, tendons, ligaments, and joint capsules

2. Nociceptors– Pain

3. Chemoreceptors– Smell and taste

4. Photoreceptors– Light

The CNS and PNS• Muscle Spindles

– Sensitive to change in muscle length and rate of length change– When a muscle spindle is stretched, an impulse is immediately sent to the

spinal cord, and a response to the muscle is received within 1-2 milliseconds

– Activation will cause muscle contraction• Golgi Tendon Organs (GTO)

– Located where muscles insert into tendons– Sensitive to changes in muscles tension and rate of change– Activation will cause muscle to relax

• Joint Receptors– Respond to pressure, acceleration, and deceleration of joint– Act in extreme positions, or end ROM– Ex: Ruffini endings and Pacinian corpuscles

Divisions of The Skeletal System• Joints are where movement occurs in response to muscle

contraction• 206 bones in the skeletal system

– 177 used in voluntary movement!• Bones in body form over 300 joints• Bones function as leverage and support (posture)• Skeletal System divided into 2 divisions

1. Axial Skeleton• Skull, rib cage, and vertebral column

2. Appendicular Skeleton• Upper and lower extremities• Shoulder and pelvic girdle• Consists of 126 bones

Bones

• Remodeling: The process of resorption and formation of bone

• Osteoclasts: A type of bone cell that removes bones tissue

• Osteoblasts: A type of cell that is responsible for bone formation

• Remodeling tends to follow the lines of stress placed on the bone

Types of BonesBone Type Characteristic Example

Long Long, cylindrical shaft and irregular or widened ends

Humerus, femur

Short Similar in length and width; somewhat cubical in shape

Carpals of hand, tarsals of feet

Flat Thin, Protective Scapulae, patella, ribs

Irregular Unique shape and function Vertebrae

Sesamoid Small often round bones embedded in a joint capsule or found in locations where a tendon passes over a joint

Patella

Long Bones

• Anatomic Features of a Long Bone– Epiphysis: long, end part of bones

• Mainly composed of cancellous bone• Houses much of the red marrow involved in RBC production• Primary sites for bone growth (epiphyseal growth plate)

– Diaphysis: Shaft portion of a long bone• Predominantly compact bone• Inside of the shaft is hollow• Principle role is support

– Epiphyseal Plate: connects the diaphysis to the epiphysis

Long Bones

• Periosteum: tough, fibrous membrane that coats the bone, except the ends of bones (synovial membrane)

• Medullary Cavity: the central cavity of the bone shafts where marrow is stored

• Articular (Hyeline) Cartilage: covers the articular surfaces of bones– helps reduce friction in freely movable synovial

joints

Short Bones

• All similar in length and width, appear slightly cubical in shape

• Consists primarily of spongy bone tissue to maximize shock absorption

• The carpals of the hands and tarsals of the feet fit this category

Flat Bones

• Thin bones comprising two layers of compact bone tissue, surrounding a layer of spongy bone tissue

• Involved in protection of internal structures• Provides broad attachment sites for muscles• Examples include: sternum, scapulae, ribs, ilium,

and cranial bones• Sesamoid bones: embedded in a joint capsule or

found in locations where a tendon passes over a joint

Bone Markings

• Surface markings of bones can be divided into two simple categories– Depressions: flattened or indented portions of the

bone• Common depression is a fossa• Another type is called a sulcus

– Groove in bone that allows soft tissue to pass through

– Processes: projections protruding from the bone where muscles, tendons, and ligaments attach• Some of the more common processes are called processes,

condyles, epicondyles, tubercles, and trochanters

Vertebral Column

• Atlas• C1-C7• T1-T12• L1-L5• Sacrum• Coccyx• The adult spine has 3 major curvatures

1. Posterior cervical2. Anterior thoracic3. Posterior lumbar

Joints

• Joint motion is referred to as Arthrokinematics, with 3 major types1. Roll: one joint rolls across the surface of another,

both constantly changing contact surface2. Slide: one joint’s surface slides across another• like sliding on ice

3. Spin: one joint surface rotates on another much like twisting the lid off a jar

Classification of Joints

• Synovial Joints: Joints that are held together by a joint capsule and ligaments and are most associated with movement in the body– Comprise 80% of all the joints in the body– Have the greatest capacity for motion– All have a synovial capsule surrounding joint, a

synovial membrane (inner layer), and hyaline cartilage which pads the ends of articulating bones

Synovial Joints

• Gliding Joint: a nonaxial joint that either moves back and forth, or side to side.– ex: navicular bone and 2nd and 3rd cuneiform bones

• Condyloid: condyle of one bone fits into the elliptical cavity of another bone– Movement predominantly occurs in one plane (flexion

and extension)• Hinge: uniaxial joints allowing movement mainly in

sagittal plane.– Ex: toes, knees, elbows, and ankles

Synovial Joints• Saddle: one bone looks like a saddle with the articulating

bone straddling it like a rider– Allows for movement in two planes of motion (flexion and

extension in sagittal plane, adduction abduction in frontal plane• Pivot: allow movement in mainly one plane of motion

(rotation, pronation, and supination in the transverse plane)– Ex: proximal radioulnar joint in elbow

• Ball-and-Socket: most mobile of the joints, movement in all three planes– Ex: shoulder and hip

• Nonsynovial Joints: no joint cavity, little to no movement– Ex: sutures of skull, distal joint of tibia and fibula

The Structure of Skeletal Muscle

• 3 major types– Skeletal– Cardiac– Smooth

The Structure of Skeletal Muscle

• Skeletal muscle, comprised of multiple bundles of muscle fibers held together by connective tissue

• The muscle is surrounded by the epimyseum; a layer of connective tissue underneath the fascia

• Perimysium: The connective tissue that surrounds fascicles

• Endomysium: The deepest layer of connective tissue that surrounds individual muscle fibers.

• Tendons: Connective tissues that attach muscle to bone and provide an anchor for muscles to produce force

Muscle Fibers and Their Contractile Elements

• Muscle fibers are encased by a plasma membrane known as the sarcolemma and contain cell components such as cellular plasma called sarcoplasm

• Myofilaments are the contractile components of muscle tissue

• The actin and myosin filaments form a number of repeating sections within a myofribril– Each of these sections are known as a Sarcomere– A Sarcomere is the functional unit of the muscle

Muscle Fibers

• Two protein structures that are also important to muscle contraction are tropomyosin and troponin

• Tropomyosin– located on the actin filament– blocks myosin binding sites located on the actin

filament– Keeps Myosin from attaching to actin where in

muscle contraction

Neural Activation• Skeletal muscles will not contract unless they are stimulated to do so by

motor neurons• Neural Activation: The contraction of a muscle generated by neural

stimulation• Motor Unit: a motor neuron and all of the muscle fibers it innervates• Motor neurons originating from the CNS communicate with muscle fibers

through the neuromuscular junction• Electrical Impulses a.k.a. “action potentials” are transported from CNS

down to the axon of the neuron• When the impulse reaches the end of the axon (axon terminal)

neurotransmitters are released.• Neurotransmitters: Chemical messengers that cross the neuromuscular

junction (synapse) to transmit electrical impulses from the nerve to the muscle– the neurotransmitter used by the neuromuscular system is Ach (acetylcholine)– Ach stimulates muscle fibers to contract

Sliding Filament Theory

• Describes how thick and thin filaments within the sarcomere slide past one another, producing force

• Excitation-contraction Coupling: process of neural stimulation creating a muscle contraction– Series of steps that start with neural activation

and end with muscle contraction

“All or Nothing” Law

• Muscles are divided into motor units• A single motor unit consists of one motor

neuron and the muscle fibers it innervates• If stimulus is strong enough to trigger action

potential, then whole muscle fiber will be innervated. If not, it won’t be innervated– Motor units cannot vary the amount of force they

generate

“All or Nothing” Law

• Size of motor unit relate directly to the function of the muscle

• The more precise the movement required from the muscle, a lesser amount of motor units are found.

• Precise movements = fewer motor units so synapses can control movement better.

Muscle Fiber Types

• Type I (slow-twitch): muscle fibers contain a large number of capillaries, mitchondria, and myoglobin– Mitochondria creates ATP from food– Myoglobin transports oxygen

• Type II (fast-twitch): subdivided into type IIa and type IIx– Type IIa: Intermediate fast-twitch, can use both

aerobic and anaerobic metabolism almost equally– Type IIx: pure fast-twitch, entirely anaerobic

Muscles as Movers

• Agonist muscles are muscles that act as prime movers

• Synergist muscles assist prime movers during movement

• Antagonist muscles perform the opposite action of the prime mover

The Endocrine System• The endocrine system secretes hormones into the

bloodstream to regulate a variety of bodily functions– Control of mood– Growth and development– Tissue function– Metabolism

• Consists of host organs (known as glands), chemical messengers (hormones), and target cells (receptor cells)

• The term “endocrine” means hormone-secreting• The endocrine system affects nearly all forms of human

functioning

Endocrine Glands• The primary endocrine glands are the hypothalamus, pituitary, thyroid,

and adrenal– Pituitary: “Master gland”, controls all other glands. Has 3 different lobes;

Anterior, Intermediate, and Posterior• Anterior

– growth hormone– Prolactin

» Milk production after birth – ACTH (adrenocorticotropic hormone)

» Stimulates the adrenal glands – TSH (thyroid-stimulating hormone)– FSH (follicle-stimulating hormone)

» Stimulates ovaries and testes– LH (lutenizing hormone)

– Also stimulates ovaries and testes• Intermediate

– Melatoncyte-stimulating hormone» Control skin pigmentation

• Posterior– ADH (anti diuretic hormone)

» To increase absorption of water into the blood by kidneys– Oxytocin

» Contracts the uterus during childbirth and stimulates milk production

• The thyroid gland produces hormones that regulate the rate of metabolism and affect the growth and rate of function of many other systems

• Adrenal glands secrete hormones in response to stress such as:– Corticosteroids– Catecholamines

• Cortisol• Adrenaline (epinephrine)

Insulin, Glucagon, and Control of Blood Glucose

• Carbohydrate is the primary energy source during vigorous exercise– Also principle fuel for the brain– Control of blood glucose is regulated by the pancreas, which produces

insulin and glucagon• Insulin helps regulate energy ad glucose metabolism in the body

– After consuming a meal, glucose enters the blood at the small intestine, giving rise in blood glucose levels.• Circulating insulin binds with receptors of target cells, which let them into

cells.• Causes cell membranes in the brain and muscles to become more permeable

to glucose• Causes drop in blood glucose levels

Glucagon

• One of the two hormones secreted by the pancreas that regulate blood glucose levels

• Functions to raise blood glucose levels by triggering the release of glucagon.– Stimulates the liver to convert its glycogen stores

back into glucose, which is then released to the bloodstream.

– Organs become less permeable to glucose to keep blood glucose levels high.

Adrenal, Pituitary, Reproductive, and Thyroid Hormones

• The adrenal gland (sits on top of each kidney) produces two catecholamines (fight or flight)

• Help prepare the body for activity.– Stress response known as “fight or flight”– Hypothalamus triggers adrenal glands to secrete – Epinephrine (adrenaline) (fight)

• Increases heart rate and stroke volume• Elevates blood glucose levels• Redistributes blood to working tissues• Opens up airways

– Noreepinepthrine

Hormones

• Males produce up to 10 times more testosterone than females

• For males and females, testosterone plays a fundamental role in the growth and repair of tissue

• Raised levels of testosterone indicative of anabolic training status

Hormones• Cortisol: typically referred to as a catabolic hormone

– During stress, cortisol is secreted by adrenal glands; saves energy by breaking down carbohydrates, fats and protein

• Growth Hormone: released from the pituitary gland in the brain and is regulated by the hypothalamus

• Thyroid Hormone: primarily responsible for metabolism– Basal metabolic rate, protein sysnthesis, sensitivity to– epinephrine, heart rate, breathing rate, and body temp

Chapter 3

The cardiorespiratory System

Introduction

• The cardiorespiratory system is comprised of the Cardiovascular System and the Respiratory System

• The Cardiovascular System is comprised of– Heart– Blood vessels– Blood

• The Respiratory System is comprised of– Trachea– Bronchi– Alveoli– Lungs

The Cardiovascular System

• Transport blood from the heart to the tissues of the body

• The Heart– Muscular pump that rhythmically contracts– Contained in the area of the chest known a the

mediastinum– Approximately the size of a human fist– Weighs roughly 300 g (10 ounces)– Involuntary muscle; can’t be consciously controlled

The Cardiovascular System• Cardiac muscle fibers are lined up like skeletal muscle,

but are much shorter and more tightly connected• Irregularly spaced dark bands between cardiac cells are

called intercalated discs– Helps hold muscle cells together during contraction– Create an electrical connection between cells that allow heart

to function as a coordinated unit• The heart has it’s own built-in conduction system to

generate muscle contraction– Typical resting heart rate (RHR) is between 70-80 beats per

minute (bpm)

The Heart

• Located in the right atrium of the heart, the SA node initiates an electrical signal that is transmitted through the heart via a network of internodal pathways– SA node referred to as the pacemaker of the heart

• After the impulse leaves the SA node, it’s transferred to the AV (antrioventricular) node.– AV node delays impulse before relaying impulse to

ventricles via right and left branches of Purkinje Fibers

Structure of the Heart• The Ventricles are large chambers located inferiorly on either side of the

heart• The atria are smaller chambers, located superiorly on either side of the

heart• The four heart valves are:

– the tricuspid valve, located between the right atrium and the right ventricle;– the pulmonary (pulmonic) valve, between the right ventricle and the pulmonary

artery;– the mitral valve, between the left atrium and left ventricle; and– the aortic valve, between the left ventricle and the aorta.

• The right side of the heart is referred to as the pulmonic side b/c it receives blood from the body that is low in oxygen.

• The left side is referred to as the systemic side because it pumps blood high in oxygen to the rest of the body

Healthy Blood Flow Pattern• From the body to the heart

– Dark bluish blood, low in oxygen, flows back to the heart after circulating through the body

– It returns to the heart through veins and enters the right atrium. – This chamber empties blood through the tricuspid valve into the right ventricle.

• From the heart to the lungs– The right ventricle pumps the blood under low pressure through the pulmonary valve

into the pulmonary artery– From there the blood goes to the lungs where it gets fresh oxygen

• From the lungs to the heart– After the blood is refreshed with oxygen, it's bright red. – Then it returns to the left heart through the pulmonary veins to the left atrium– From there it passes through the mitral valve and enters the left ventricle.

• From the heart to the body– The left ventricle pumps the red oxygen-rich blood out through the aortic valve into

the aorta– The aorta takes blood to the body's general circulation– The blood pressure in the left ventricle is the same as the pressure measured in the

arm.

Function of the Heart

• Stroke Volume: The amount of blood pumped out of the heart with each contraction– SV (stroke volume) is the difference between

ventricular end-diastolic volume (EDV) ad the end-systolic volume (ESV)

– EDV in a typical heart is about 120 ESV and 50 mL of blood EDV, making the stroke volume about 70 mL

• Heart Rate: The rate at which the heart pumps• Cardiac Output (Q) Heart rate X stroke volume; the

overall performance of the heart

Blood

• Blood: Fluid that circulates in the heart, arteries, capillaries, and veins, carries nutrients and oxygen to all parts of the body, and also rids the body of waste

• There are three kinds of cells in the blood– Red blood cells– White blood cells– Platlets

Blood• Red blood cells carry oxygen from the lungs throughout the body• White blood cells help fight infection• Platelets help with clotting• Plasma makes up about 55% of total volume of blood

– The remaining 45% is made of red blood cells, white blood cells, and platelets

• Blood helps regulate body temperature by transferring heat from the internal core out to the periphery of the body as blood circulate throughout the body

• Blood is essential in regulation of pH levels, as well as maintaining water content of the body

Blood Vessels• Vessels form a closed circuit of hollow tubes that allow blood

to be transported to and from the heart• There are three major types of blood vessels

– Arteries• Carry blood away from heart

– Capillaries• Site of exchange of water and chemicals between the blood and the tissues

– Veins• Carry blood back to the heart

• Vessels that collect blood from the capillaries are called venules– Merge with other venules to form veins

The Respiratory System

• Respiratory System: a system of organs that collects oxygen from the external environment and transports it to the bloodstream

• The Respiratory system includes airways, lungs, and the respiratory muscles

• The primary role is to ensure proper cellular function

• Via the heart, works closely with the cardiovascular system

Mechanisms of Breathing• Breathing is the ctual process of moving air in and out of

the body, which requires optimal functioning of the Respiratory pump

• Respiratory Pump: comprised of skeletal structures (bones) and muscles that work together to allow proper respiratory mechanics to occur and help pump blood back to heart during inspiration

• Inpiration: The process of actively contracting the inspiratory muscles to move air into the body

• Expiration: process of actively or passively relaxing the inspiratory muscles to move air out of the body

Mechanisms of Breathing

• When the Intrapulmonary pressure decreases below that of the atmospheric pressure, air is drawn into the lungs

• Inspiratory ventilation occurs in two forms: active and passive

• Normal breathing requires the use of the primary respiratory muscles (diaphragm, external intercostals)

• Heavy breathing requires the additional use of the secondary respiratory muscles (scalenes, pectoralis minor)

Structures of the Respiratory Pump

Bones SternumRibsVertebrae

Muscles Inspiration DiaphragmExternal IntercostalsScalenesSternocleidomastoidPectoralis Minor

Expiration Internal intercostalsAbdominals

Structures of the Respiratory Passages

• Conducting airways– Nasal cavity– Oral cavity– Pharynx– Larynx– Trachea– Right and left pulmonary bronhi– Bionchioles

• Respiratory airways– Alveoli– Alveolar sacs

Respiratory Airways

• Diffusion: The process of getting oxygen from the environment to the tissues of the body

• Respiratory airways collect channeled air coming from airways.– At the end of the bronchioles sit the alveoli, which

are made up of clusters of alveolar sacs– In the alveolar sacs, gases such as oxygen and

carbon dioxide are transported in and out of the blood stream via diffusion

Cardiorespiratory System Function

• Air is inhales through nose or mouth• Conducted through the trachea• Down through the bronchi• Eventually reaches the lungs and alveolar sacs• While this is happening, deoxygenated blood is pumped

from right ventricle to the lungs through pulmonary arteries

• Pulmonary capillaries surround the alveolar sacs, and as oxygen fills the sacs, oxygen diffuses across the capillary membranes and into the blood

Oxygen Consumption• Resting oxygen consumption (Vo2) is appx 3.5 mL of

oxygen per kilogram of body weight per minute– Typically termed 1 metabolic equivalent or 1 MET.

– Vo2 = Q x a – vo2 difference

• The equation for oxygen consumption is known as the Fick Equation.

• Vo2max is the best measure of cardiorespiratory fitness, but needs to be measured directly with a machine

• Maximal oxygen consumption– The highest rate of oxygen transport and utilization achieved

at maximal physical exertion

Abnormal Breathing Patterns• The breathing pattern becomes more shallow, using the secondary

respiratory muscles predominantly in the diaphragm– Can become habitual– Causes overuse to the scalenes, sternocleidomastoid, levator scapulae, and

upper trapezius– Respiratory muscles also play a major postural role in the human movement

system.• Increased activity may cause headaches, lightheadedness, and dizziness.

• Excessive breathing (short, shallow breaths)– Can lead to altered carbon dioxide and oxygen blood content– Can lead to feelings of anxiety that further initiate breathing response

• Inadequate oxygen and retention of metabolic waste within muscles can create fatigue and stiffness

– Inadequate motion at the spine and rib cage can also cause joints to become restricted and stiff.

Chapter 4

Exercise Metabolism and Bioenergetics

Bioenergy and Metabolism

• Bioenergetics: The study of energy in the human body• Metabolism: All of the chemical reactions that occur in

the body to maintain itself– Metabolism is the process in which nutrients are acquired,

transported, used, and disposed of by the body• Exercise Metabolism: The examination of bioenergetics

as it relates to the unique physiologic changes and demands placed on the body during exercise

• Substrates: The material or substance on which an enzyme acts

Bioenergetics and Metabolism

• The ultimate source of energy is the sun• Proteins, carbohydrates, and lipids (fats) are

main sources of substrates used to transfer metabolic energy to be used for all types of cellular activity

• Carbohydrates: main source of ATP needed to fuel anaerobic workouts.– Primary source of glucose– Made of carbon, hydrogen, and oxygen

Fuel for Energy Metabolism

• Glycogen: The complex carbohydrate molecule used to store carbohydrates in the liver and muscle cells.– Glycogen is converted to glucose, to be used by

muscle cells• Fat: helps the body use some vitamins and

keep the skin healthy– also serves as energy stores for the body

Energy and Work

• One of the primary sources of immediate energy for cellular metabolism is stored in the chemical bonds of a molecule called ATP (adenosine triphosphate)– ATP yields energy for cellular work (i.e. muscle

contraction) and ADP (adenosine diphosphate)– Using the products of energy metabolism

Energy and Mechanical Work

• Any form of exercise can be define by Intensity and Duration.

• ATP is a high-energy molecule that stores energy to be used in cellular and mechanical work

• Only about 40% of the energy released from ATP is actually used for cellular work– The remainder is released as heat

ATP

• ATP ↔ ADP + Pi + energy release• Before ATP can release additional energy again,

it must add back an additional phosphate to the ADP through phosphorylation

• 3 metabolic pathways that can release ATP– The ATP-PC system– The glycolytic system (glycolysis)– The oxidative system (oxidative phosphorylation)

ATP-PC System• Once an ATP has been used, it must be replenished before it can

provide high-energy molecules can phosphocreatine• Together, ATP and PC are called phosphagens• The ATP-PC system is sometimes referred to as a

phosphocreatine model• Simplest and fasted of the energy systems• Occurs without the presence of oxygen• Provides energy for high-intensity, short duration activity• During all-out sprint, could supply energy to muscles for about

10-15 seconds• System is activated at onset of activity, regardless of intensity

Glycolysis• Involves the chemical breakdown of glucose• Occurs in the cytoplasm of the cell• Although can produce significantly greater energy than ATP-PC

system, it slower to act and only lasts about 30-50 seconds• Most fitness workouts will place a greater stress on this system

than the other systems– A typical repetition range of 8-12 reps falls within this time frame

• By-product of anaerobic glycolysis is lactic acid• By-product of aerobic glycolysis is Pyruvic acid

– Pyruvic acid can be used in the oxidative system, lactic acid cannot

The Oxidative System• Only occurs in the mitochondria• Begins to work after about 2 minutes when other systems are depleted• Essentially unlimited, can run indefintely• Takes a long time to work, and does not produce a lot of force• Metabolism of one glucose molecule produces between 35-40 ATP• The Three oxidative systems include

– Aerobic glycolysis (with oxygen)– The Krebs Cycle (without oxygen)– The Electron Transport Chain (ETC)

• In the prescence of oxygen, pruvic acid is converted into Aceltyl CoA, which is then used in the Krebs Cycle

• The complete oxidation of acetyl CoA produces 2 units of ATP– By-products are carbon dioxide and hydrogen

The Oxidative System• Fat can metabolized aerobically• The first step in oxidation of fat is referred to as beta-

oxidation– Process begins with breakdown of triglycerides into smaller

subunits called free fatty acids (FFA)– FFA’s can then can be converted into acetyl CoA, which then are

available to enter the krebs cycle• Depending on what kind of fat is oxidized, one molecule

produces 129 ATP molecules• However, carbohydrates are the preferred fuel substrate

for the oxidative production of ATP

Metabolism During Intermittent Work

• Oxygen consumption remains high for a short period after cardiovascular exercise, referred to as excess postexercise oxygen consumption (EPOC)

• ATP is needed for recovery and the aerobic metabolic pathways are the most efficient and consistent source.

• Recovery of the ATP-PC cycle is complete in approximately 90 seconds

• The longer the period of high-intensity work, the longer the recovery.

• Thus, even in sports like football, periods of training need to address aerobic energy production efficiency– Cardio training helps the ATP-PC system recover faster during competition

Estimating Fuel Contribution During Exercise

• The respiratory quotient (RQ) is the amount of carbon dioxide (C02) expired divided by the amount of oxygen consumed– Measured during rest of at steady state of exercse using a

metabolic analyzer• During steady-state exercise, an RQ of 1.0 indicates

that carbohydrate is supplying 100% of fuel• RQ of 0.7 indicates that fat is supplying 100% of the

fuel• 0.7-1.0 means a mix of fats and carbs

Chapter 5

Human Movement Science