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72 Cards in this Set
- Front
- Back
What is the definition of physical activity? |
Physical activity encompasses all leisure and non-leisure body movement produced by the skeletal muscles, which results in an increase in energy expenditure over resting levels. |
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What are the four classifications of physical activity? |
- Occupational - Domestic - Transportation - Leisure-time |
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What is the definition of physical fitness? |
A set of attributes or characteristics that people have (or achieve) that relates to their ability to perform physical activity |
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What are the two categories that physical fitness are categorized into? |
- General fitness (a state of health and well being) - Specific fitness (a task oriented definition based on the ability to perform specific aspects of a sport or physically demanding occupation) |
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Define health-related fitness |
Ability to carry out daily tasks with vigor and alertness, without undue fatigue, and with ample energy to enjoy leisure-time pursuits and meet unforeseen emergencies. |
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Define performance-related fitness |
Physical training for a specific task like a recreational sport or a physically demanding job. |
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What is the main risk of being physically inactive? |
The fact that it is recognized as 1 of 4 common risk factors for non-communicable diseases. Also it's ranked 4th among the 5 leading causes of global mortality. |
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Define a MET |
-Metabolic Equivalent -Amount of energy used for resting metabolism |
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What does 1 MET equal to?
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1 MET = resting VO2 = 3.5mL x kg-1 x min-1 |
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What are the four components of physical fitness? |
-flexibility -cardiovascular -musculoskeletal -body composition |
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Define cardiovascular fitness |
The ability of the cardiovascular and cardiopulmonary systems to deliver an adequate supple of O2 to the working muscles. |
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What is VO2max? |
The oxygen uptake attained during maximal exercise intensity that could not be increased despite further increases in exercise workload. |
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What are the components of VO2? |
Q x a-VO2diff HR x SV (CaO2 - CvO2) |
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What are the four factors that determines VO2max? |
-Pulmonary diffusing capacity -Maximal cardiac output -O2 carrying capacity -Skeletal muscle characteristics |
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What are the two types of musculoskeletal endurance? |
- Strength endurance: capacity to resist fatigue during repeated contractions with loads greater than 30% of maximum concentric strength - Muscle endurance: the ability of a muscle to resist fatigue during repeated contractions |
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What type of musculoskeletal fitness are there? |
-Muscular endurance -Muscular strength -Muscular power |
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Define muscular strength
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maximum force developed by a muscle/muscle group in a single maximal voluntary contraction |
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Define muscular power |
ability to produce a large amount of work in a short period time (rate of performing work) |
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define flexibility |
range of motion around a joint or series of joints |
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why is body composition important ? |
assessing body weight (BW) and body fat (BF) distribution is important. Excess BF increases risks of health problems |
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What are 4 ways to asses body composition? |
-Hydrostatic weighing -Skinfold measurements -Bioelectrical impendence (electric thing with hands) -DXA, MRI, CT scans |
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Epimysium
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Surrounds entire muscle and blends into intramuscular tissue sheaths to form tendons |
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Perimysium |
Surrounds a bundle of fibers called fasciculus |
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Endomysium |
wraps each muscle fiber and separates it from neighbouring fibers |
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sarcolemma |
surrounds each muscle fiber and encloses fiber's cellular contents |
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sarcoplasm |
contains nuclei that house genes, mitochondria, and other specialized cells |
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sarcoplasmic reticulum |
provides structural integrity |
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tendons |
connect both ends of muscle to periosteum (bone's outermost covering) |
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difference between origin and insertion of a muscle |
-origin: where the tendon joins a relatively stable skeletal part, generally the proximal end - Insertion: the point of distal attachment to the moving bone |
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Skeletal muscle blood supply |
blood flow oscillates during rhythmic activities (vessels compress during contraction, open during relaxing)
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Skeletal muscle microstructure |
•Single multinucleatedmusclefibercontainsmyofibrils thatlie parallelto fiber’slongaxis •Myofibrils containsmallersubunitscalledmyofilaments thatlieparalleltolongaxisof myofibril •Myofilaments consistofactinandmyosinthataccount for~85%of myofibrillar complex •Other proteinseitherservestructuralfunctionor affectproteinfilament interactionsduringmuscleaction •Tropomyosin, troponin,α-actinin,β-actinin, M protein,andCprotein |
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Myofibril has a cross-striation pattern: |
•I band represents lighterarea •A band represents darkerarea •CenterofAband containsthe H zone •M band bisectsH zone;and consistsof proteinstructures thatsupport arrangement of myosinfilaments •Zline bisectsI bandand adheres to sarcolemmatoprovidestructuralstability |
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what is the skeletal muscle microstructure of a sarcomere? |
consists of basic repeating unit between two z lines; comprises the functional unit muscle fiber |
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How do muscle fibers shorten? |
Occurs due to the movement of the actin filament over the myosin filament (myosin crossbridges cyclically attach, rotate and detach from actin filaments with energy from ATP hydrolysis) |
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Step 1 of sequence of events in muscle action |
Generationof actionpotentialinmotor neuron causes terminal axontorelease acetylcholine (ACh),whichdiffusesacross synaptic cleft andattachestospecialized AChreceptorsonsarcolemma
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Step 2 of sequence of events in muscle action |
Muscle action potential depolarizes the transverse tubules at sarcomere's A-I junction |
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Step 3 of sequence of events in muscle action |
depolarization of t-tubule system causes calcium release from lateral sacs of sarcoplasmic reticulum |
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Step 4 of sequence of events in muscle action |
calcium binds to troponin-tropomyosin in actin filaments, releasing the inhibition that prevented actin from combining with myosin |
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Step 5 of sequence of events in muscle action |
-Actin combines with myosin-ATP; this activates myosin ATPase, which splits ATP -The reaction's energy produces myosin crossbridge movement and creates tension |
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Step 6 of sequence of events in muscle action |
•ATPbindstomyosincrossbridgewhich breaksactin–myosinbond,allowing actin disassociation fromthecrossbridge •Thickand thin filamentsthen slidepasteach other and muscleshortens |
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Step 7 of sequence of events in muscle action |
Crossbridgeactivation continueswhenCa2+ concentrationremainshighenough toinhibit troponin–tropomyosinsystem |
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Step 8 of sequence of events in muscle action |
Whenmuscle stimulationceases, intracellularCa2+ concentrationrapidly decreasesasCa2+ movesbackintolateral sacsof sarcoplasmicreticulum through active transport; requiresATPhydrolysis |
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Step 9 in sequence of events in muscle action |
•Ca2+ removalrestores inhibitoryactionof troponin–tropomyosin •Inpresenceof ATP,actinand myosinremain in dissociated,relaxedstate |
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What four characteristics do type 2 fibers display? |
1.Highcapabilityforelectrochemical transmissionofactionpotentials 2.High myosinATPaseactivity 3.RapidCa2+ releaseand uptakeby efficient sarcoplasmicreticulum 4.High rateofcrossbridgeturnover |
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Type 2 fibers: |
•Intrinsicspeed of shortening and tensiondevelopmentrangesfrom 3to 5 times fasterthanslow-twitchfibers •Relyonwell-developed,short-term glycolytic system forenergytransfer •Activationpredominates in anaerobic-typesprintactivitiesand other forcefulmuscleactionsthatrely entirely on anaerobic energy transfer •Activationplaysan importantrole in stop-and-goorchange-of-pace sports such as basketball, soccer,tennis,etc. |
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What do type 1 fibers do? |
Generate energy for ATP resynthesis through aerobic system of energy transfer |
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what are the four distinguishes characteristics of type 1 fibers? |
1.Low myosinATPaseactivity 2.Slowcalciumhandling ability and shorteningspeed 3.Lesswell-developed glycolyticcapacity than fast-twitchfibers 4.Large andnumerousmitochondria |
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Main difference between type 1 and type 2 fibers |
type 1 is more fatigue resistant, type 2 is more spontaneous |
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Define a motor unit |
-makes up functional unit of movement -consists of a motor neuron and specific muscle fibers it innervates *each muscle fiber generally receives input from only 1 motor neuron; a motor neuron may innervate many muscle fibers* |
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Motor unit functional characteristics: |
based on three physiological and mechanical properties of the muscle fibers they innervate -twitch characteristics -tension characteristics -fatigue |
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What are the three training principles? |
-Overload -Progression -Specificity |
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What is meant by "overload" when in comes to training principles? |
- Thetraining stimulus must be greaterthan thattowhichthebody isaccustomed. - Increasefrequency,intensity, durationor thenumberof repetitions and sets, or decreasethe recoverytimein aprogram. |
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What is meant by "progression" when in comes to training principles? |
- Theinitialworkloadmustincrease (progress) toensure continued improvement. |
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What is meant by "specificity" when in comes to training principles? |
Training effects arespecific to the energy system used (i.e.,aerobic or anaerobic), as well asthe muscle groups, joint actions and type/speed of muscle contraction. |
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What are the six main types of muscle actions? |
-Concentric -Isometric -Eccentric -Dynamic constant contraction -Dynamic variable contraction -Isokinetic muscle contraction |
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What is a concentric muscle action? |
The tension developed in the cross-bridges of a muscle is sufficient to overcome any resistance to shortening |
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What is an isometric muscle action? |
The tension in the cross-bridges equals the resistance to shortening, and the muscle length remains relatively constant |
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What is an eccentric muscle action? |
The tensionin the cross-bridgesisless thantheexternal resistanceandthemuscle lengthensdespitecontactbetweenmyosin cross-bridgesheadsand actinfilaments. |
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what is dynamic constant contraction? |
muscle action against a constant external resistance (isotonic) ex: free weights |
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what is dynamic variable contraction? |
muscle action against a changing external resistance. ex: bungee or band |
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what is isokinetic muscle contraction? |
muscle action which occurs at a constant velocity allowing for maximal force generation throughout the entire movement (biodex) |
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Exercise order: |
power --> non power (core) --> assistance exercise (leg press and such) |
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what is plyometric training? |
a quick, powerful movement using a pre-stretch, or countermovement, that involves the stretch-shortening muscle |
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how does plyometric training help improve? |
muscle force and power production, which is explained by two proposed models (mechanical model, neurophysiological model) |
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What is the mechanical model in plyometric training? |
-elastic energy of the musculotendious components is increased with rapid stretch (eccentric action) and then stored -if immediately followed by a concentric action, the stored energy is released and force production increased -most of the elastic component in the system is in the tendons. the system acts as a spring, which stores energy as it is lengthened |
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What is the neurophysiological model in plyometric training? |
-the stretch reflex is the body's response to an external stimulus that stretches the muscle -muscle spindles are proprioceptive organs that are sensitive the rate and magnitude of the stretch -when a quick stretch is detected, muscular activity reflexively increases and muscle fibers contract -plyometric exercises produce rapid stretches and stimulate the muscle spindles, causing a reflexive muscle action, which increases force production |
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what are neural adaptations? |
adaptive altercations in nervous system function that elevate motor neuron output account for rapid and large strength increases early in training, without increases in muscle size and CSA |
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difference between intermuscular and intramuscle coordination? |
-inter: improved feedback between muscles and CNS, improved coordination of MU activation (size principle) -intra: rate of MU firing, number of MU recruited, sychronization of the signal |
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Muscular adaptations (hypertrophy) |
Increase in muscular tension (forcing) with training provides main stimulus to initiate muscle growth |
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how does ATP form? |
ATP forms from adenosine linked to three phosphate |
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how does ADP form? |
when ATP joins with water, catalyzed by the enzyme adenosine triphosphate (ATPase) |
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what is the PCr system? |
the energy reservoir - some energy for ATP resynthesis comes from anaerobic splitting of a phosphate from PCr |