Exam #1 Flashcards
(134 cards)
1
Q
Define physiology
A
Physiology: the study of the function of organism, typically at rest
2
Q
Define exercise physiology
A
Exercise physiology: the study of how body structure and function are altered by exposure to acute and chronic exercise
3
Q
Define environmental physiology
A
Environmental physiology: the study of the effects of the environment on the function of the body
4
Q
Define sport physiology
A
Sport physiology: the application of the concepts of exercise physiology to training athletes and enhancing sport performance
5
Q
Define ergometer
A
Ergometer: “work-measure”; used to measure physical work under standardized conditions
— allows the intensity of exercise to be controlled and measured
— a certain type of ergometer is used depending on the individual’s training for accurate results
6
Q
Define longitudinal study
A
Longitudinal study: tests the same subjects and compares results over time
— follows the same subject for a long time
7
Q
Define cross-sectional study
A
Cross-sectional study: collects data from a diverse population and compares groups in that population
— randomly assign individuals to groups (control or experimental group)
8
Q
Define acute exercise/acute bout of exercise
A
Acute exercise: a single bout of exercise; high intensity exercise for a short period of time
— EX: Putting subject on a treadmill for an hour
9
Q
Define chronic adaptation
A
Chronic adaptation: a physiological change that occurs when the body is exposed to repeated exercise bouts over a period of weeks or months. These changes generally improve the body’s efficiency at rest and during exercise
10
Q
When did the field of exercise physiology began to evolve?
A
Early 20th century
- Due to increase of interests in exercise and health as well as in rehabilitating and training soldiers
11
Q
(a) When was the first true laboratory exist?
(b) What was it called?
(c) Who was it founded by?
(d) How many years was it open?
(e) Who was the director of the lab the entire time it was open?
(f) When did the lab disbanded?
(g) W/n the time it was open, how article did the lab publish?
A
(a) 1927
(b) Harvard Fatigue Lab
(c) Biochemist, Lawrence J. Henderson
(d) 20 years
(e) D.B. Dill
(f) 1947
(g) 352 research papers
12
Q
What are the two most common types of ergometers? List both of its advantages and disadvantages.
A
- Treadmills
Advantages:
- Walking is a natural activity for everyone
Disadvantages:
- Most people achieve their peak values for most physiological variables, but some athletes require higher level mode of ergometer
- More expensive, bulky, not portable, require power
- Difficult to get accurate measurement of BP - Cycle ergometers
Advantages:
- Does not depend on the subject’s weight (weight independent)
Disadvantages:
- Leg muscle fatigue if subject does not regularly exercise = peak exercise intensity, not true maximal intensity
13
Q
Between longitudinal studies and cross-sectional studies, which is more accurate?
A
Longitudinal studies are often more accurate than cross-sectional studies
— But are time-consuming and expensive
14
Q
What can be some confounding factors during research? List some examples
A
Many factors can alter the body’s response to exercise (individual may not respond to exercise)
— EX: environmental conditions, time of day (dinurnal variation)
15
Q
How can you identify what information is being presented in tables and graph?
A
The title
16
Q
What do graphs better illustrate?
A
— Trends in data
— Response patterns
— Comparisons of data between subject groups
17
Q
What does the x-axis of a graph represent?
A
the independent variable or factor that is controlled by the study design
— EX: putting someone on a treadmill and changing their speed
18
Q
What does the y-axis of a graph represent?
A
the dependent variable that will change depending on how the independent variable is manipulated
— EX: measuring the blood lactate of an individual who has been running on treadmill with a certain speed
19
Q
Be able to identify, label, and identify the anatomy of a muscle fiber/muscle cell (8)
A
- Plasmalemma (plasma membrane/cell membrane): separates what outside and inside of the cell
- Opening into T-tubule: allows the outside of the cell membrane to enter inside of the cell; AP will travel here resulting in release of Ca2+
— Transverse tubules: deep invaginations/extension of plasma membrane; important for depol., diffusion, and gases efficiency - Sarcoplasmic reticulum: contains Ca2+; important for contraction process
- Sarcoplasm: gel-like substance w/n muscle cell containing/stores fuel: carbohydrates/glycogen + fatty acids/triglycerides
- Mitochondria: energy units; producing ATP aerobically
- Nucleus: located on the perimeter of the cell, multi-nucleated tissue; # of nuclei determines muscle atrophy
- Myofibril
20
Q
Be able to identify, and label, the anatomy of a sarcomere and its protein
A
Regions of sarcomere
* Z-disks/line: “book-end” of the sarcomere
* I-band: lIght region/band; only actin filaments
* A-band: dArk region/band; contains both actin and myosin residing
* H-zone: lighter region between A-band; only myosin
* M-line: “midline/middle” of sarcomere
Proteins of sarcomere
* Actin filaments: thin filaments that attach to z-line, in the I-band
- Nebulin: the frame that actin filaments is built on
* Myosin filaments: thick filaments
- Titin: large protein that tethers myosin to z-disk + provide passive tension to muscle when in resting condition
21
Q
What is a sarcomere?
A
the smallest functional building block of the myofibril
22
Q
Describe the structure of a myosin filament
A
Myosin head
- 360 degree globular head
- Consists of ATPase; helps with with the hydrolysis of ATP to ADP + Pi
Hinge regions (2)
- Helps with the process of powerstroke and crossbridge formation
23
Q
What is the actin filament composed of?
A
Molecules of actin, tropomyosin, and troponin
24
Q
What is the protein that provides structural rigidity and ensuring the standard length of a sarcomere across all mammalian tissue?
A
Nebulin
25
What is tropomyosin?
An inhibitory protein molecule that prevents myosin head from making contact w/ myosin binding site of actin filament
26
What is troponin?
A big protein that will assist cross-bridge to form by moving tropomyosin
— Made up of three isoforms:
- Tni - inhibitory subunit
- Tnc - area where Ca2+ binds to
- Tnt - makes contact with tropomyosin
27
How many actin molecules surrounds one myosin molecule
6 actin molecules
28
What occurs during excitation of skeletal muscle contraction? (6)
Occurs at NMJ
(1) Action potential (AP) arrives at axon terminal, releases acetylcholine (ACh)
(2) ACh crosses synaptic cleft, binds to ACh receptors on plasmalemma (plasma membrane/cell membrane)
(3) AP travels down plasmalemma, T-tubules
(4) Triggers Ca2+ release from sarcoplasmic reticulum (SR)
(5) Ca2+ binds to Troponin
(6) Tropomyosin undergoes a conformational change and exposes the myosin binding site on actin
29
How does AP cause the release of Ca2+ from SR?
As AP travels down the t-tubules, a voltage-sensing protein that's located w/n the t-tubules senses AP and send signals to SR, causing the release of Ca2+
30
What occurs during contraction of skeletal muscle contraction?
* Cross bridge formation - myosin head makes physical contact with actin
* Power Stroke/Sliding Filament
– Myosin head pulls actin toward sarcomere center (power stroke)
~Myosin ATPase hydrolyzes ATP to fuel powerstroke
– Filaments slide past each other
– Sarcomeres, myofibrils (H-zone, I-band, Z-disks), muscle fiber all shorten
31
What occurs during relaxation of skeletal muscle contraction?
* AP ends, electrical stimulation of SR stops; no more signal (AP) = SR stops release of Ca2+
* Ca2+ pumped back into SR
– Stored until next AP arrives
– Requires ATP
* Without Ca2+, troponin and tropomyosin return to resting conformation
– Covers myosin-binding site
– Prevents actin-myosin cross-bridging
32
What energy is necessary for muscle contraction (powerstroke) to occur? What does it do?
Adenosine triphosphate (ATP) is necessary for muscle contraction
* Binds to myosin head
– ATPase on myosin head
– ATP → ADP + Pi + energy
33
Distinguish which hinge joint of a myosin molecule is used for which part of contraction?
Primary hinge joint - Cross bridge
Secondary hinge joint - Powerstroke
34
What are the three types of muscle fibers?
Type I (Slow twitch/Slow Oxidative)
Type IIa (Fast twitch/Fast Oxidative/Glycolytic)
Type IIb (Fast twitch/Fast Glycolytic)
35
Distinguish type I fibers vs. type IIA fibers vs. type IIX fibers in terms of color. Explain why
Color
Type I: Red
- Has high concentration of myoglobin, which transports O2 to the muscle fiber, especially to the mitochondria
Type IIa: Pink (medium amt. of myoglobin)
Type IIb: White
- Not so much myoglobin as it relies on the sarcoplasm of the muscle cell, as this muscle fiber type uses glycolytic pathway as energy source
36
Distinguish type I fibers vs. type IIA fibers vs. type IIX fibers in terms of fiber diameter. Explain why
Fiber diameter
Type I: Small
- Decreases diffusion distances to easily exchange waste and gases
Type IIa: Midsize
Type IIb: Large
- Has a lot more protein packed in this muscle fiber
37
Distinguish type I fibers vs. type IIA fibers vs. type IIX fibers in terms of capillary density. Explain why
Capillary density
Type I: High
- Has more avenues for O2 (from myoglobin) to be delivered to bring to our mitochondria
Type IIa: Medium
Type IIb: Low
- Does not need much O2 for the energy source (glycolytic) that type IIb m. fiber uses
38
Distinguish type I fibers vs. type IIA fibers vs. type IIX fibers in terms of mitochondrial density. Explain why
Mitochondrial density
Type I: High
- Since it relies on aerobic (oxidative) ATP, there will be a higher volume of mitochondria
Type IIa: Medium
Type IIb: Low
- Does not use mitochondria for energy source
39
Distinguish type I fibers vs. type IIA fibers vs. type IIX fibers in terms of myosin ATPase type. Explain why
Myosin ATPase type
Type I: Low
- Given that the contraction of this fiber type is slow, therefore the hydrolysis of ATP occurs at a lower rate before contraction take place
Type IIa: Medium
Type IIb: High
- Given that the contraction of this fiber type is fast, the hydrolysis of ATP occurs at a faster rate before contraction take place
40
Distinguish type I fibers vs. type IIA fibers vs. type IIX fibers in terms of Ca2+ handling capacity. Explain why
Ca2+ handling capacity
Type I: Low
- SR network is not as extensive enough to release high amounts of Ca2+, thus causing a slow rate of contraction
Type IIa: Medium
Type IIb: High
- Has a higher developed SR network to release more Ca2+ for a faster rate of contraction
41
Distinguish type I fibers vs. type IIA fibers vs. type IIX fibers in terms of glycolytic capacity. Explain why
Glycolytic capacity
Type I: Low
- Does not rely on glycolytic pathway for energy source
Type IIa: Medium
Type IIb: High
- Relies on glycolytic pathway for energy source
42
Distinguish type I fibers vs. type IIA fibers vs. type IIX fibers in terms of oxidative capacity. Explain why
Oxidative capacity
Type I: High
- Able to produce ATP much higher
Type IIa: Medium
Type IIb: Low
- Does not use aerobic pathway to produce energy
43
Distinguish type I fibers vs. type IIA fibers vs. type IIX fibers in terms of speed of contraction. Explain why.
Speed of contraction
Type I: Slow
- Cross-bridge cycles and powerstroke occur very slowly due to low myosin ATPase + low Ca2+ handling capacity
Type IIa: Medium
Type IIb: Fast
- Cross-bridge cycles and powerstroke occur very fast due to high myosin ATPase + high Ca2+ handling capacity
44
Distinguish type I fibers vs. type IIA fibers vs. type IIX fibers in terms of speed of relaxation. Explain why
Speed of relaxation:
Type I: Slow
- Ca2+ is not able to pump back into the SR as quickly as it can therefore, troponin and tropomyosin cannot return to its resting conformation
Type IIa: Medium
Type IIb: Fast
- Ca2+ is able to pump back into the SR as quickly as it can therefore, troponin and tropomyosin can return to its resting conformation
45
Distinguish type I fibers vs. type IIA fibers vs. type IIX fibers in terms of fatiguability. Explain why.
Fatiguability
Type I: Low
- Due to a slower rate of contraction and relaxation, this fiber type is highly fatigue resistant; (EX: soleus)
Type IIa: Medium
Type IIb: High
- Due to a faster rate of contraction and relaxation, this fiber type is fatigues easily
46
Distinguish type I fibers vs. type IIA fibers vs. type IIX fibers in terms of force capacity. Explain why.
Force capacity
Type I: Low
- Does not generate much force due to smaller proteins, thus smaller myofibrils and it's contractile units
Type IIa: Medium
Type IIb: High
- Generates a higher amount of force due to having greater amounts of protein, thus more myofibrils and it's contractile units
47
How are fiber types determined?
Genetic factors
– Determine which α-motor neurons innervate fibers (type I motor neurons = type I muscle fibers)
– Fibers differentiate based on α-motor neuron
(# of muscle fibers and its innervation don't change)
48
What is the fiber type distribution percentage?
w/n a normal mixed muscle (vastus lateralis)
* Type I - 50%
* Type IIa – 30-40%
* Type IIb/x – 10-20%
- not every muscle in the body has a 50/50 distribution, it depends on the job of that muscle
49
What is orderly recruitment?
As intensity of activity increases, skeletal m. contraction recruits minimum number of motor units needed:
– Smallest (type I) motor units recruited first
– Midsized (type IIa) motor units recruited next
– Largest (type IIx) motor units recruited last
NOTE: Recruited in same order each time
50
What is size principle?
order of recruitment of motor units directly related to size of α-motor neuron
51
Name the different anatomical structures parts of a neuron and discuss the function of each.
1. Dendrites - receive signals/AP then carry the impulses toward the cell body
2. Cell body - known as soma; size will determine what muscle fiber types it determines
— Axon hillock
3. Axon - where AP travels through until it reaches axon terminal
4. Axon terminal
— End branches → Axon terminal
52
What is resting membrane potential (RMP)?
* Difference in electrical charges between outside and inside of cell; aka polarized
* Cause by uneven separation of charged ions
— High [Na+] outside vs. High [K+] inside
* RMP = -70mV; inside is more negative
53
What regulates/resets RMP after AP?
Na+/K+ pump
* 3 Na+ out and 2 K+ in
54
How does AP propagates along an axon?
Goes in one direction
— Segments of the axon sequentially depol. (which causes new AP to the adjacent segment of the axon) and then repol.
55
How does AP occur in a postsynaptic neuron?
A graded potential from a summation of both EPSP + IPSP, MUST reach threshold (-50mV)
56
What is meant by the all-or-none law of action potential formation?
An action potential occurs as long as it reaches a threshold (-50mV)
57
What happens during depolarization? What ion enters the cell?
Once neuron hits threshold (-50mV), AP occurs, causing membrane potential to be positive (depol.)
— Voltage-gated Na+ channels open = Na+ rapidly enters cell
When membrane potential reaches 0mV, Na+ channels will start to close
58
What happens during repolarization? What ion exits the cell?
Membrane potential starts to become negative (repol.) after depol.
— Once membrane potential reaches its peak (+30mV); K+ channels start to open
— K+ starts to exit out the cell to the extracellular fluid when K+ channels open; eventually returning to RMP but hyperpolarization will occur
59
What happens during hyperpolarization?
Membrane potential becomes further negative than its RMP (hyperpol.) due to K+ channels remaining open for too long, causing an additional efflux of K+ ions
60
What is the myelin sheath?
A layer of fat that insulates/keeps the charge inside of axon
— Not continuous
61
What disease is associated with the break down of the myelin sheath?
Multiple sclerosis (MS)
- More energy is used up
- Individual is more tired and have hard time controlling movements
62
What is the Node of Ranvier?
Node of Ranvier - gaps between the myelin sheath that exposes surface area of an axon
— Depol. and repol. occurs w/n this region
63
What is saltatory conduction and why is it efficient for AP?
Saltatory conduction - AP (depol + repol.) will jump and occur from each segment of node of Ranvier
— Effecient as it allows a faster rate of AP propagation
64
What is the difference between a synapse vs. a postsynaptic tissue/neuromuscular junction
Synapse: axon terminal → dendrites
Neuromuscular junction (NMJ): axon terminal (alpha motor neuron) → muscle fibers
65
What occurs during a synapse?
- As AP travels down the axon and arrive at the axon terminal, it causes neurotransmitter vesicles to exocytose out the presynaptic neuron
- Neurotransmitters will diffuse onto the synaptic cleft and bind to it's receptor on the postsynaptic neuron
- Depol. may occur if there is enough NTs binding to receptors that reaches threshold
66
What does the motor unit consists of?
Motor unit = α motor neuron + the muscle fiber (cells) it innervates
- all will be the same fiber types
67
How can fine motor muscle and gross motor/power force muscle be dictated?
By the number of muscle fiber that is being innervated (that is depending on the function of the muscle itself)
- Large number of muscle fibers innervated by α motor neuron = gross motor/power force muscle
- Small number of muscle fibers innervated by α motor neuron = fine motor muscle
68
How many neurotransmitters (NT) are known/suspected?
50+ NTs
69
What are the two major categories of NTs?
- Small molecule, rapid acting
- Large molecule neuropeptides, slow acting
70
What are the two NTs that govern exercise? What do they do?
ACh and norepinephrine (NE)
- ACh stimulates skeletal muscle contraction, mediates parasympathetic nervous system effects!
- NE mediates sympathetic nervous sytem effects
71
What are the two divisions of peripheral nervous system?
1. Sensory (afferent) nerves
2. Motor (efferent) nerves
72
What are the two divisions of motor (efferent) nerves?
1. Autonomic (involuntary control)
2. Somatic (voluntary control)
73
What are the two divisions of autonomic?
1. Sympathetic - "fight or flight"
2. Parasympathetic - "rest and digest"
74
When is the parasympathetic nervous system active?
At rest
75
What does the parasympathetic stimulation include? (4)
– ↑ Digestion, urination
– Conservation of energy
– ↓ Heart rate
– ↓ Diameter of vessels and airways
76
Which autonomic nervous system prepares body for exercise + is in control when doing exercise
Sympathetic nervous system
77
What does the sympathetic nervous system include? (5)
– ↑ Heart rate, blood pressure
– ↑ Blood flow to muscles
– ↑ Airway diameter (bronchodilation)
– ↑ Metabolic rate, glucose levels, FFA levels (energy source)
– ↑ Mental activity
78
Distinguish the action that sympathetic vs. parasympathetic nerves produce on the following: Heart muscle
Sympathetic: Increases the rate and force of contraction
Parasympathetic: decreases rate of contraction
79
Distinguish the action that sympathetic vs. parasympathetic nerves produce on the following: Heart - coronary blood vessels
Sympathetic: Cause vasodilation
Parasympathetic: Cause vasoconstriction
80
Distinguish the action that sympathetic vs. parasympathetic nerves produce on the following: Lungs
Sympathetic: Cause bronchodilation; mildly consrict BV's
Parasympathetic: Cause bronchoconstriction
81
Distinguish the action that sympathetic vs. parasympathetic nerves produce on the following: Blood vessels
Sympathetic: Increase BP
Parasympathetic: Little or no effect
82
Distinguish the action that sympathetic vs. parasympathetic nerves produce on the following: Liver
Sympathetic: Stimulate glucose release
Parasympathetic: No effect
83
Distinguish the action that sympathetic vs. parasympathetic nerves produce on the following: Cellular metabolism
Sympathetic: Increases metabolic rate
Parasympathetic: No effect
84
Distinguish the action that sympathetic vs. parasympathetic nerves produce on the following: Adipose tissue
Sympathetic: Stimulates lipolysis
Parasympathetic: No effect
85
Distinguish the action that sympathetic vs. parasympathetic nerves produce on the following: Sweat glands
Sympathetic: Increases sweating
Parasympathetic: No effect
86
Distinguish the action that sympathetic vs. parasympathetic nerves produce on the following: Adrenal glands
Sympathetic: Stimulate secretion of NE and epinephrine
Parasympathetic: No effect
87
Distinguish the action that sympathetic vs. parasympathetic nerves produce on the following: Digestive system
Sympathetic: Decreases activity of glands and muscles; constricts sphincters
Parasympathetic: Increases peristalsis and glandular secretion; relaxes sphincters
88
Distinguish the action that sympathetic vs. parasympathetic nerves produce on the following: Kidneys
Sympathetic: Causes vasoconstriction; decreases urine formation
Parasympathetic: No effect
89
What is sensory-motor integration?
how the nervous/sensory system receives info and how it gets processed through the motor systems
90
What does the sensory division do?
Transmits information from periphery to brain
- Just RECIEVES info. and send these signals to higher brain center, which will then translate it + respond to it
91
What are the 5 major families of sensory receptors?
– Mechanoreceptors: physical forces
– Thermoreceptors: internal and external temperature; received by hypothalamus
– Nociceptors: pain
– Photoreceptors: light; found w/n eye(rods+cones)
– Chemoreceptors: chemical stimuli; finds the right internal environment for physiological function
92
What are the 5 sequence of events of a sensory-motor integration?
receptor (receive signal) → brain (respond to the signal)
1. A stimulus to the skin is received by sensory receptor (e.g., nocicipetor)
2. AP travels through SENSORY NEURONS to the CNS
3. The CNS interprets the information and determines the motor response or reflexively initiates the appropriate motor response
4. The motor action potential travels out from the CNS through MOTOR NEURONS
5. The AP reaches the muscle fibers and the response occurs
93
What is a motor reflex?
Motor reflex: Instant, preprogrammed response to a given stimulus
– Response to stimulus identical each time
– Occurs before conscious awareness
* Impulse integrated at lower, simple levels (spinal cord; NO brain involved)
94
What are muscle spindles and their function? Where are they found?
Located in the muscle
Muscle spindles: Provide info. of the length of the muscle (short or long)
— Part of mechanoreceptors
95
Regarding sensory-motor integration, detail the location of the muscle spindle, its structure and the significance of the structure when explaining its function using a real-world example.
The muscle spindle, a mechanorecpetor, is a coil shaped receptor that is located in the muscle. It informs the higher brain center of what length the muscle is at, be it long or short.
A real-world example of a functioning muscle spindle would be the book drop test demonstrated in class. We are instructed to hold the arm at a 90 degree angle with the command from our higher brain centers. When the book was dropped onto the arms, the muscles of the arms bounced a bit, getting pushed into extension. This causes the coil shaping of the muscle spindle to lengthen, thus causing the gaps between the coils to distance themselves. The distance/length between the gaps will then inform the high brain center of this new length that gotten moved due to this external force. Because the higher brain center has initially commanded to maintain the 90 degree angle and it has gotten out of that preferred place, it responds by recruiting the correct amount of motor to recover back to its normal position.
96
What are Golgi tendon organs and their function? Where are they found?
Located in the tendons
Golgi tendon organs: Senses strain/tension across a tendon
— Part of mechanoreceptors
— Does more reflex response; provides inhibitory signals to antagonist muscles
97
Define strength
Strength: determined by the maximum amt. of weight the individual could bench press JUST ONCE (1RM)
98
Define power
Power: determined as the athlete performed the 1RM test as explosively as possible
— P = (F x d)/t
* F - force (weight lifetd)
* d - distance lifted from chest to full arm extension
* t - time it took to complete the lift
99
Define muscular endurance
Muscular endurance: only for resistance exercise; determine by the greatest number of repetitions that could be completed using 75% of the 1RM
100
1. What is the difference between a novice weightlifter vs. another individual who has been weightlifting for a while (years)? Explain why? What do their early gains appear to be a result from?
2. If the novice weightlifter continues to lift after 3 weeks, what would their gains now be a result from?
1. The amount of weight the novice weightlifters lifts has a stagnant increase compared to someone who has lift for a long time. This typically occurs w/n early neural adaptations which results in their early gains of strength
2. Their later long-term gains are largely the result from muscle hypertrophy + strength
~ genetics can play role in hypertrophy as well steroids
101
What are some neural mechanisms/changes that occur when someone continues strength/resistance training?
1. ↑in frequency of stimulation (or rate coding - # of motor units recruited for the action)
2. recruitment of more motor units
3. more synchronous recruitment of motor units
4. decreases in autogenic inhibition from the Golgi tendon organs; so they're able to generate more force + tension
102
Define muscle hypertrophy and fiber hypertrophy and fiber hyperplasia
Muscle hypertrophy: Increase of muscle size
Fiber hypertrophy: Increase of muscle fiber size
Fiber hyperplasia: splitting of muscle fibers = ↑ # of fibers = ↑CSA if size increases
- HOWEVER, this is not accurate
103
What are the 4 mechanisms of muscle strength gain in fiber hypertrophy?
1. More myofibrils
2. More actin + myosin filaments
3. More sarcoplasm (↑ volume)
4. More connective tissue - (30%)
104
What is the sequence of protein synthesis? (4)
Occurs at the nucleus
1. Replication of DNA
2. Transcription (mRNA synthesis)
3. Arrival at ribosome
4. Translation (protein synthesis)
105
What causes protein synthesis? What results from protein synthesis?
Resistance training → ↑ rate of protein synthesis = fiber hypertrophy
106
How does muscle protein content change during and after exercise?
Muscle protein content always changes
— During exercise: ↓ synthesis, ↑ degredation
— After exercise: ↑ synthesis, ↓ degredation
107
What natural anabolic steroid hormone facilitates fiber hypertrophy?
Testosterone
108
What does synthetic anabolic steroids do to muscle mass?
Creates a large increase in muscle mass
109
Explain the process of how protein synthesis is initiated? What does this result?
The mechanical stretch applied to muscle in resistance training will stimulate the release of growth factor. Growth factor will then activate mTOR in order to initiate protein synthesis. With protein synthesis in will then result in muscle hypertrophy
110
Explains the effects growth factor had between an 8-hour rest, 24-hour rest, and 48-hour rest
8-hour rest - no change in the amt. of growth factor; supress the positive effect of GF and from the previous workout
24-hour rest - small difference from 8-hour
48-hour rest- has better result of initiating protein synthesis
111
How long should one wait for their next training session to optimize muscle hypertrophy?
about 48 hours
112
When does acute muscle soreness occur? What causes this? When does it disappear?
— During, immediately after exercise bout
— Caused by:
* Accumulation of metabolic by-products (H+); pH in muscle goes down
* Tissue edema (plasma fluid into IF)
* Edema → acute muscle swelling
— Disappears w/n minutes (20-30mins) to hours
113
What does DOMS stand for and what is it? What are some of its major causes and give an example. What is it NOT caused by?
DOMS: Delayed-onset muscle soreness
— 1 to 2 days after exercise bout
— Type I muscle strain
— Ranges from stiffness to severe, restrictive pain
Major cause: high tension eccentric contraction (can cause a busted cell membrane)
— Caused by muscle damage
— Example: Level run pain < downhill run pain
— NOT CAUSED BY: ↑ blood lactate concentrations
114
What is the sequence of events when DOMS occurs? (3)
1. High tension eccentric contractions in muscle → structural damage to muscle, cell membrane (disruption of plasmalemma)
2. Membrane damage disturbs Ca2+ homeostasis in injured fiber (Ca2+ goes to the outside of cell)
- Inhibits cellular respiration (mitochondria)
- Activates enzyme that degrade z-disks
- Leads to cellular necrosis (cell death) within 24-48 hours post exercise
3. (a) Products of macrophage activity, (2) accumulate intracellular contents (histamine, kinins, K+)
- Stimulate pain in free nerve endings; (due to K+ leaking out and interacting w/ free nerve endings)
- Worse with eccentric exercise
115
Why must we reduce DOMS and what are some ways?
* Must reduce DOMS for effective training
* Three strategies to reduce DOMS
— Minimize eccentric work/load early in training
—Start with low intensity and gradually increase
— Or start with high-intensity, exhaustive training (soreness bad at first, much less later on)
116
Should men and women be trained differently? What are some of the differences between men and women that pertain to muscle size?
No! Men and women should be trained for their sport, not their gender.
- Women's peak 1RM < men's peak 1RM
- They have the same ability to develop strength, however...
- Differences due to muscle size (due to testosterone, men have a greater CSA, but theres is no difference in muscle fiber between men and women)
117
Can children/adolescents and the elderly do resistance training? What are some of the benefits for both age groups?
Yes!
* Children and adolescents
- Safe with proper safeguards
- Children can gain both strength and muscle
- Can start preteen, but limited
* Elderly
- Helps restore age-related loss of muscle mass
- Improves quality of life and health
- Helps prevent falls
- Inactivity is due to loss of function
118
Is the data from the Metropolitan Life Insurance Company of New York considered useful?
No! It's considered useless.
118
What are some the 6 things to consider when making a progressive resistance exercise training program/plan?
1. 3-RM to 12-RM most effective number of reps to improve strength
2. Training once/week with 1-RM for 1 set increases strength significantly after 1 week of training and continues to increase strength thereafter for up at least 6 weeks
3. Perform at least 1 set of 10-RM each training session
4. Performing 1 set of an exercise is less effective than 2 or 3 sets and 3 sets may be better than 2
5. Training 4-5 days a week may be less effective than 2-3 times/week. Daily training of the same muscle group may delay increases in strength
6. Neither free weights or machines are inherently superior in terms of strength developments.
119
What is the BMI useful for?
The BMI is considered useless.
120
What percentage is considered the storage fat and essential fat for both men and women according to Behnke's theoretical model?
Men:
Storage fat - 12.0% (18.5lb)
Essential fat - 3.0% (4.0lb)
Total - 15%
Women:
Storage fat - 15.0% (18.8lb)
Essential fat - 12.0% (15.0lb)
Total - 20-25%
121
Why do we need a good amount of fat for our body? Why do women have a higher fat content compared to men?
Men: Hormonal purposes need for health
Women: For pregnancy
122
What does the assessment of body composition in sport provide?
Provides more information
- Height and weight is not enough to know fitness status
- ↑ Percent body fat, ↓ performance
123
What are the 5 ways that body composition can be measured?
1. Densitometry/hydrostatic weighing
2. DEXA
3. Air plethysmography
4. Skinfold
5. Bioelectric impedance
124
What does densitometry measure? How does it work?
Densitometry (D): measures body density
D = MASS/VOLUME
– Hydrostatic (underwater) weighing
– Muscle/FFM (1.1 g/mL) heavier than water (1.0 g/mL), fat/FM (0.8 g/mL) lighter than water
– Most commonly used method
125
A man weighs 210lbs and is at 20% bodyfat. He wants to sit at about 13% body fat. How many pounds of body fat does he have to lose to accomplish his goal? What is his goal weight in pounds? At his new weight, how many pounds of fat does he have?
Original weight: 210 lbs
Original BF%: 20%
Desired BF%: 13%
Bodyfat lbs: 42 lbs (= 210 lbs x 20%)
(MAINTAIN) Lean mass lbs: 168 lbs
Goal weight: 192 (= 168 lbs / 87%)
100% - 13% of desired BF% = 87% FFM
Goal fat loss lbs: 18 (= 210 lbs - 192 lbs)
New BF lbs at goal weight: 25 lbs (= 13% x 192)
126
What is fat-free mass? How does it affect sport performance?
Fat-free mass (FFM): includes muscle
– Important variable for athletes to know
– ↑ Good for power, strength, muscle endurance
– But bad for aerobic endurance (more mass to carry)
127
What is relative body fat? What are some of the exceptions, sport-wise, in having a relative body fat?
Relative body fat/Fat mass (FM): percent body fat
– Fat: dead weight but useful energy store
– Less fat usually = better performance
– Exceptions: sumo wrestler, swimmer, weight lifter
128
How much is 1 pound of fat equal to?
3,500 kcals
129
What is basal metabolic rate?
Basal metabolic rate: aka resting metabolic rate; how much fat is burned if one was to simply lay down
130
What is the basal metabolic rate for men and women?
* Males
– 1600 – 1800 Kcal/day
* Females
– 1200 – 1400 Kcal/day
131
What should we avoid when we want to achieve our optimal weight? Why?
Avoid fasting and crash diets
– Cause more water and muscle loss, less fat loss
– Ketosis (diet w/o carb) accelerates water loss; store carb = store water
~ Reduction in glycogen+carbs causes the loss of water weight first
~ However, when carb is reintroduced in diet, the water gain will increase
132
What are some things we can do if we want to achieve optimal weight loss? (3)
Optimal weight loss: ↓ fat mass, ↑ FFM
- Moderate caloric restriction + exercsie
- Caloric deficit ~200 to 500 kcal/day
- Lose no more than 0.5 to 1lb/week
- When near goal, slow weight loss further
133
What does 1 gram of carbohydrates, protein, and fat equal to?
CHO = 4KCAL
PRO = 4 KCAL
FAT = 9KCAL
