Unit 2 - Physical HealthHow Exercise Affects the Systems of Your

Body

Physical HealthHow well your body functionsWhy exercise?

Can help prevent: Cardiovascular disease Certain cancers Diabetes High Blood Pressure

Improves Stamina, Flexibility, and StrengthControls WeightImproves Quality of Life

Affects both social and mental health

Physical HealthAffects every system in your bodyKey systems to be discussed:

CardiovascularRespiratoryMuscularSkeletalNervous

Brain

Cardiovascular SystemCardiovascular System – AKA the Circulatory System – is an

organ system that encompasses the heart and blood vessels of the body

Function - carries blood, oxygen, and nutrients to organs and tissues of the body, and carries waste and carbon dioxide from these tissues for removal from the body

Heart causes blood to flow away from the heartBodily movement causes blood to efficiently flow back to the heart

Muscles pressing on veins help push blood back towards the heart

The heart is a constantly working muscle

The HeartAny exercise will strengthen muscle

More exercise = stronger heart

Stronger heart = less work to do at restHigher cardiac output – more blood is expelled from the

heart per beat

Less work to do at rest = lower resting heart rate (RHR)

More exercise = better blood and oxygen flow

Blood Vessels and PressureIncreased exercise will increase cardiac

output and lower heart rate

Helps regulate fluid and promotes capillary formation

Amount of fluid in blood greatly determines blood pressureMore fluid = more pressure

Respiratory SystemFunction - to supply the blood with oxygen in

order for the blood to deliver oxygen to all parts of the body

Made up ofMouthNoseTracheaLungsDiaphragm

Respiratory SystemImproves lung capacityBlood flow increases to alveoli

Allows better Oxygen / CO2 exchange

Respiratory SystemControls mucus which may settle in the lungs

Increases endurance of Diaphragm and Intercostals

Muscular SystemHelps with strength and endurance

Supply and demandThe more you exercise, the more demand there

is on your muscles which leads to an increase in strength and endurance

More exercise = more blood flow = increased muscle growth

Diagram of a Skeletal Muscle

Muscular System1. Increase workload = increased stress on muscles2. Increased stress result in micro-tears in muscle

fibers3. Natural repair process repairs the tear

a) Overcompensates by adding bigger cells to build a stronger fiber.

b) Over time, this repeated process of teardown and re-build will result in muscle growth

Hypertrophy – muscle growth Your body does not actually make more muscle but the muscle

fibers which make up your muscle get larger

Muscular SystemAn established exercise routine results in an

increase in Mitochondria in musclesMitochondria use oxygen to create energy

Glucose + Pyruvate + NADH = ATP (adenosine triphosphate)

Process occurs because of the presence of oxygen

Increase in number of blood vessels in muscle tissue

Muscular SystemSkill - a learned ability to bring about the

result you want with maximum certainty and efficiency

Four components a skill must have:It is learnedHas an end resultShould be performed under controlShould use the minimum amount of energy

Muscular SystemLearning a new skill…Information Processing

When we are learning a new skill our brains must take in, process and use a lot of information about the skill and environment.

Four steps for information processing when learning a new skill take place…

Muscular System1. Input – information your brain receives

(what you see, hear, and feel)

2. Decision Making –  brain processes this information and decides how to react

3. Output – a result of your decision

4. Feedback – shows success or failure

Muscular SystemTwo types of feedback

Intrinsic – how performing the skill felt

Extrinsic – effectiveness of the performance and judgment by coaches, parents, teammates, etc. Did the ball land where you wanted it to? Did your coaches tell you how to perform better?

Muscular SystemSkills are either basic or complexBasic Motor Skills

Most are learned at an early ageTransferable between different sports and situationsMust be mastered before moving on to complex skillsExamples - running, hopping, dodging an opponent

Complex Motor SkillsRequire more coordination and controlTend to be specific to a particular sport (i.e. non-

transferable)A lot of practice to masterExamples - smash shot in badminton, a tennis serve,

basketball lay-up

Muscular SystemSkills can be either open or closedOpen Motor Skills – affected by external

factorsHitting a pitched baseball will be affected by

your position, the position of your opponents, the type and speed of pitch, playing conditions, previous at-bats, etc.

Closed Motor Skills -  performance is self-controlled with very little effect from environment or other peopleSuccessfully throwing a dart to a specific

target is completely in the individual’s control.

Muscular SystemOpen and closed continuum

Most skills fall in between open and closed The more outside factors there are, the more open a

skill will be

Why is goaltending in hockey more closed than competitive sailing?

Which is a more open skill, hitting a ball off of a tee or hitting a pitched ball? Why?

Muscular SystemNeuromuscular effects

Neuromuscular system is the interaction between your muscles and the nerves that control them

Increase in repetitive exercise = more muscle fibers to be activated and better timing of muscle contractions

Leads to increased strength and coordination

Muscular SystemTwo types of practice

Blocked and random

Blocked - a learner performs a single skill over and over, with repetition being the key 50 free throws, 50 elbow jumpers, 50 baseline

jumpers

Muscular SystemRandom – a learner works on a number of

different skills in combination with each other, randomly working trials and patterns of one and then the next and the nextOne 17-foot jump shot, back pedal to your

three-point line, side-shuffle in defensive stance across the court, dribble a basketball, make a chest pass, cut to the basket, box-out for a rebound

Muscular System

Which do you think leads to better learning?

Muscular System

Blocked – performing an action over and over again without break causes the individual to stop thinking about the solution

Becomes a mindless activityEvidence shows it leads to a false sense of

accomplishment when practicing in controlled, blocked sessions.

Used for beginners learning a new, complex motor skill

Muscular SystemRandom

Forces the learner to become more actively engaged in the learning process by preventing simple repetitions of actions.

Gives the learner more meaningful and distinguishable memories of the various tasks, increasing memory strength and decreasing confusion among tasks.

Causes the learner to forget the short-term solutions (from working memory) to the movement problem after each task change.

 Forgetting the short-term solution forces the learner to generate the solution again on the task’s next trial, which is beneficial to learning.

“Forgetting facilitates learning”

Muscular SystemMajor points:

Physical activity promotes strength, endurance, and coordination

Circulatory and nervous system adapt to physical demands

Practicing new motor skills places demand on the neurons in your brain to work harder to learn how to master the skill

Basic before complexContinuous relearning leads to retention

Skeletal SystemConsists of:

Bones, ligaments, and cartilage

Functions - support, movement, protection, blood cell production, calcium storage and endocrine regulation 

Skeletal SystemDiagram of a Bone

Skeletal SystemBones

Contain marrow that produce blood cellsLigaments

Fibrous connective tissue attached to bones and many internal organs Helps limit movements induced by tendons Keeps internal organs in place

CartilageHolds some bones together, helps in the

formation of bones in growing children and prevents bones from rubbing each other.

Skeletal SystemPhysical Activity promotes:

Increased synovial fluid production

Maintains and increases joint range of movement

Increased bone density

Stronger ligaments

Skeletal SystemSynovial Fluid – oil-like fluid produced at

joints to keep cartilage lubricated and nourishedProduction of synovial fluid is an acute (short-

term) response to exercise More exercise means = more synovial fluid Joints need regular exercise to stay lubricated,

nourished and healthy. More fluid = better range of motion Lack of exercise causes joints to “dry up”

Skeletal SystemIncreased Bone Density

Weight-bearing and cardiovascular exercises put stress on bones

Body responds by creating osteoblastsOsteoblasts – cells which build new bone and

make bones stronger and denserIncreased bone density helps prevent

osteoporosisOsteoporosis – weakening of bone

Skeletal SystemStronger Ligaments

Ligaments are exposed to the same stresses of exercise

Slowly develop strength

Nervous System – The BrainMore exercise = better blood flow to the

brain

Exercise causes the release of endorphins which make you feel good

Studies show consistent exercise = better brain development in children

Underuse will result in a decline in function

The BrainExercise seems to slow or reverse the natural

declination of brain function starting in our twenties.

New studies seem to show that adult brains are capable of neurogenesis (creation of new brain cells)Adults were previously thought to be unable to

do thisExercise is thought to jumpstart

neurogenesisExercise seems to prompt an increase in

Brain-Derived Neurotropic Factor (BDNF)Exercise does not have to be exhaustive!

The BrainBDNF:Strengthens brain cells and axonsFortifies connections among neurons and

sparks neurogenesisMost people have higher levels of BDNF in

blood after exerciseThis does not fully explain all the brain

changes associated with exercise