Exam 1 Flashcards
2 Primary Groups of Fiber Type Named By The Speed Action due to..
Different Myosin Atpase
Different level of Sacroplasmic Reticulum Development
What does faster myosin removal mean?
Corresponds to Fast Twitch Muscles
How does Sacroplasmic Recticulum relate to fiber type?
Fast twitch have better developed sacroplasmic reticulum. Calcium can be released in a wider area.
What is stored in the Sarcoplasmic Reticulum?
Stores Calcium and releases it.
Slow Twitch Muscle name?
Type I or
Slow Oxidated
Fast Twitch A Name?
Type IIA or
Fast Oxidated Glycolytic
Fast Twitch B Name?
Type IIX or
Fast Glycolytic
How is a fiber type determined?
Muscle Biopsy
What is a Muscle Biopsy?
Small (10-100g) piece of muscle removed. Frozen, sliced, and examined under a microscope.
Type I Contractile Speed?
110 ms
Type II Contractile Speed?
50 ms
Motor Unit Force for Muscle Fibers from smallest to largest?
Type I < Type IIa < Type IIx
Motor Neuron Size from Smallest to Largest?
Type I < Type IIa < Type IIx
Nerve Conduction Velocity from Smallest to Largest?
Type I < Type IIa < Type IIx
Type of Myosin ATPase for Type I?
Slowest
Type of Myosin ATPase for Type II?
Fast
SR Development for Type I?
Least Developed
SR Development for Type II?
Highly Developed?
Speed of Relaxation from Slowest to Fastest?
Type I < Type IIa < Type IIx
Oxidative Capacity from Slowest to Fastest?
Type IIx < Type IIa < Type I
Myoglobin Content from Slowest to Fastest?
Type IIx < Type IIa < Type I
Color of Type I?
Red
Color of Type IIa?
Red to Pink
Color of Type IIx?
White
Mitochondrial Density from Lowest to Highest?
Type IIx < Type IIa < Type I
Capillarization (Area of Contact with Capillaries) from Lowest to Highest?
Type IIx < Type IIa < Type I
Glycogen Stores from Lowest to Highest?
Type I < Type IIa < Type IIx
Glycolytic Capacity from Lowest to Highest?
Type I < Type IIa < Type IIx
Fatigue Resistance from Lowest to Highest?
Type IIx < Type IIa< Type I
Typical Type I Fiber Make Up?
50%
Typical Type IIa Fiber Make Up?
25%
Typical Type IIx Fiber Make Up?
25%
Fiber Type Determinants: Genetic Factors
Determine which a-motor neurons innervate fibers and Fibers differentiate based on a-motor neuron.
Fiber Type Determinants: Training Factors
Can induce small changes in fiber type
Fiber Type Determinants: Aging
Muscles lose type II motor units. They tend to slow down with an increased risk of falling.
Pre-Training of Type II Fibers?
25% Type IIa and 25% Type IIx
Post-Training of Type II Fibers?
35% Type IIa and 15% Type IIx
How many Type II fibers can you change with training?
10% change from IIx to IIa
What is the nickname given to Type IIx fibers?
“Reservoir” Fibers
What percentage of Type I fibers can be converted to Type II?
Only 1-3%. Only Type IIx can be converted to Type I
What fiber type dominates Endurance Athletes?
Type I
What fiber type dominates Sprinters?
Type II
Other predictors of success for fiber types?
Cardiovascular Function
Motivation
Training Habits
Muscle Size
Graded Muscle Response
Controlling force output for a muscle organ to achieve the task at hand
3 Primary Mechanisms to Control Force Output?
Rate Coding within Individual Motor Units
Motor Unit Recruitment
Size Principle
Rate Coding Within Individual Motor Units
Send nerve signals at slow rate. Causes a twitch. We must send APs @ a fast rate. Send them until we’re at a tetanus reaction. This causes Calcium to be released with more Myosin interaction.
Motor Unit Recruitment
Use more motor units. Keep recruiting until we get to peak force.
Size Prinziple
As we recruit, we get different motor units.
Size Principle - Which is the fastest/strongest?
Type IIx is the fastest and strongest.
Size Principle - What is recruited first?
Type I first (slow)
Size Principle - Why do we use Type IIx?
For Sprinting, Lifting. This is activated last so we don’t fatigue. Take’s a lot of power to turn on.
Where is the Central Pathway Generator Found?
Found in the Spinal Cord. Control of voluntary movements.
What do the Muscles and Skeleton do?
Muscle spindles are sensory receptors that let us know how to move.
Coactivation of Antagonistic Muscles
Normal part of movement in humans; helps control movement/
What does Antagonist muscle contraction improve?
Control allowing for smooth motion.
What happens of too much antagonist muscle contraction occurs?
WIll decrease net torque in the intended direction of movement. (Reciprocal Inhibition)
What is Reciprocal Inhibition?
Need to keep antagonist contraction under control to allow appropriate net torque in direction of intended movement.
Do muscle units need to be contracted in size order or all at one time?
Neither
Asynchronous Motor Unit Recruitment
Allows for relatively constant force output while allowing fibers time to rest to prolong the activity. We tend to fire different motor units @ different times. We alternate between them.
What type of adaptations occur first in Strength Training?
Neural Adapatations
How many Neural Adapatations occur in Strength Training?
Five
What types of Neural Adaptations occur in Strength Training?
- Increased number of motor units recruited -> Decreased central governor
- Increase Reciprocal Inhibition
- Increased Synchrony of MU’s
- Increased Firing Rates
- Decreased Autogenetic Inhibition -> GTO Sensitivity Decreased
Neural Adaptions - Increased # Motor Units Recruited
Body only allows access to 80% of motor units. Can increase to 88% in extreme situations.
Neural Adaptions - Increased Reciprocal Inhibition
Teaching other muscles to resist firing
Neural Adaptions - Increased Synchrony of MU’s
Learning how to fire at the same time
Neural Adaptions - Increased Firing Rates
If they increase firing rate, they are able to then generate more foce
Neural Adaptions - Decreased Autogenetic Inhibition -> GTO sensitivity decreased
If the body not developed to be stronger, golgi tendon organ realizes they won’t rip tendon in training and allows then to use more force.
When do Neural Changes occur??
2-3 months later, you’ll see significant increase. Can’t get bigger yet because of neurological changes
What are the two possible mechanisms for growth of muscle tissue?
Hypertrophy
Hyperplasia
Hypertrophy
The most common, done at the end of puberty
They take the number of cells we have and simply make them bigger.
HYperplasia
*Usualy doesn’t happen past puberty.
Number of cells divide and bind to similar cells.
Types of Muscle Hypertrophy?
Acute/Transient Hypertrophy
Chronic Hypertrophy
Acute/Transient Hypertrophy
“Pump” (To get bigger muscles)
Fluid accumulation in muscle organ
Chronic Hypertrophy
*Actual adaptation of increasing muscle cells.
Occurs after months of training
Increase in protein synthesis that is reversible.
Simple definition of Catabolism?
Energy-yielding metabolism
Simple definition of Anabolism?
Biosynthetic Metabolism
What three things can Catabolism produce?
Heat
Utilizable Energy
Metabolic Products
What does Utilizable Energy lead to?
ATP
In Anabolism, what is ATP used for
External Nutrients
Intracellular Precursor Pool
Biosynthetic Intermediates
Biopolymers
What physical changes occur with Muscle Cell Hypertrophy?
More Myofibrils
More Actin, Myosin Filaments
More Sacroplasm (Change it. Cells bigger so we make more)
More CT (Connect to tendon, which helps muscle growth)
What are the control mechanisms of muscle growth that excite protein synthesis? (1-3)
Activity (Can get big very easily. Resistance Training) Growth Factors (Hormone Deficiancy) Amino Acids (Need to build new proteins)
What are the control mechanisms of muscle growth that prohibit protein synthesis? (4-6)
SIRT1 / AMPK
High Fat Diet
Alcohol (Inhibits Muscle Growth when broken down)
Oxidation (A lot of diseases lead to inhibition)
What does Endurance Activities do in relation to Muscle Growth?
Running doesn’t hurt this. Some people can go for runs and get msucle. It just takes a while. Extreme running inhibits muscle growth.
What is mTOR?
Causes a chemical response, leading to protein synthesis.
What does 1-5 reps focus on?
Increase neuromuscular efficiency
What does 6-8 reps focus on?
Myofibilar Hypertrophy
What does 9-15 reps focus on?
Sacroplasmic Hypertrophy
Hypertrophy Training
Typically >65% of 1RM
Focuses on ~90 b/w sets
Eccentric Loading (What causes damage to muscles)
Failure? (We need to fatigue all muscles)
What does Resistance Training do to protein synthesis?
Increases it
How many grams of protein needed after resistance exercise for muscle growth?
20-25 grams/
How many grams of protein needed for increasing muscle masss?
1.6-1.7 grams protein / kg body weight / day
Whats the recommendation for protein synthesis?
Small doses (20g) every 2-3 hours
Causes of DOMS?
Structural Damage Chemical Mediators (Inflammatory makers)
How can you cope with DOMS?
Limit eccentric contractions when starting training
Start low intensity and progress (muscles are new)
Ice/Rolling Out/Massage (try for yourself)
DOMS - Anti-Inflammatories
May reduce swelling therefore DOMS
May interfere with recovery/adaptation
This is a sign of repair occurring in the muscles
What contains larger glycogen storese?
Type II
What has slower myosin ATPase?
Type I
What contains larger amount of myoglobin?
Type I
What contains a smaller fiber diameter?
Type I
What has a lower oxidative energy production capacity?
Type II
What is the most fatigue resistant?
Type I
What is the maximum percentage of total skeletal muscles fibers that can be converted from Type IIx fibers to type IIa with training?
10
An increase in the number of excitatory signals sent per second in a motor unit leading to greater force output
Rate Coding
Activating multiple motor units to produce greater forces
Motor Unit Recruitment
Activating motor units in s sequential order from slow to fast twitch fibers as greater force is required
Size Principle
(T/F) The average human fibers total type distribution is 50% Type IIa and 50% Type IIx
False
____ fibers are recruited first due to the ___ size of the cell body of the alpha motor neuron in the motor unit
Type I, Smaller
An inhibitory graded potential can make cells more negative due to
Potassium leaving the cell, chloride entering the cell
Strength gains observed in the first month of training can be attributed to all of the following EXCEPT:
Increase in the total number of motor units recruited
Decrease in Reciprocal Inhibition
Increase motor unit synchrony
Decrease in Autogenic Inhibition
Decrease in Reciprocal Inhibition
(T/F) Motor units are fired asynchronously during prolonged low intensity activities in order to limit fatigue of muscle fibers
True
How long does Phosphocreatine last for?
10-15 seconds
How long does Anaerobic Glycolysis last for?
1-2 minutes
How long does Aerobic Metabolism of Fats last for?
Hours
How long does Aerobic Metabolism of Carbohydrates last for?
~ 90 minutes
Which of the following is a rate limiting enzyme as well as the only enzyme needed to complete ATP production in its energy pathway?
Creatine Kinase
What is the net number of ATP produced by the enzymes of anaerobic glycolysis when metabolizing 1 glucose molecule?
2
Where do humans house the vast majority of carbohydrate stores?
Muscle
Where in the cell are Kreb’s cycle enzymes located?
Mitochronidra
The difference in contraction velocity between Type I and Type II fibers is attributed, in part, to which of the follow __
Different ATPase
(T/F) Type I fibers have a more developed sarcoplasmic reticulum which allows calcium to spread through sacromere faster, in turn making this fiber type faster than other fiber types
False
The Margaria - Kalamen Test involves which motion?
Stair running
Which of the three tests takes the longest to compete?
Winggate Anaerbic Test
Vertical Jump
Margaria - Kalamen
Wingate Anaerobic Test
(T/F) The power output achieved during a Wingate test represents a participants aerobic power
False
What is the mode of exercise used for the Forestry Exercise Test?
Stepping
In the Forestry and Astrand Tests, what is the common physiological variable that is directly measured?
HR
(T/f) The Astrand Cycling Test is a shorter more intense test than the Wingate Cycling Test
False
Where are Carbohydrates primarily stored?
Muscle Glycogen
Where are Fats primarily stored?
Subcutaneous and Visceral
What are carbohydrates converted to?
Glucose
Energy of Carbohydrates?
4.1 kcal/g
Whats the main purpose of Carbohydrates?
Primary ATP substrate for muscles, brain
Where is extra glucose stored?
Stored as Glycogen in liver, muscles
Glycogen store limits?
2,500 kcal. Must rely on dietary carbohydrates to replenish
Fats main thing?
Efficient Substrate, Efficient Storage
Energy of Fats?
9.4 kcal/g
What are Fats used for?
Energy substrate for prolonged, less intense exercise.
ATP - Fats
High net ATP yeild but slow ATP production
Fats - Broken down into
Must be broken down into free fatty acids (FFAs) and Glycerol
Fats- What’s used to make ATP?
FFAs only used to make ATP
Protein basic description?
Energy substrate during starvation
Protein Energy Conversion?
4.1 kcal/g. Must be converted into another form to be used in energy production.
What can Protein be converted into?
Glcose (When needed)
FFAs (Lipogenesis) (For energy storage and celllar energy substrate)
What is a Rate Limiting Enzymes?
Control the rate of enzymatic energy pathways
What can Rate Limiting Enzymes do?
Can create bottleneck at an early step
Activey influenced by negative feedback
Slows overall reaction, prevents runaway reaction
How much ATP is stored?
Only for a few seconds of energy
Three ATP Synthesis Pathways?
ATP-PCr System (Anaerobic Metabolism) Glycolytic System (Anaerobic Metabolism) Oxidative System (Aerobic Metabolism)
ATP-PCr System name and description?
Phospho-Creatine System
Anaerobic, Substrate Level Metabolism
ATP-PCr ATP Yield?
1 ATP : 1 PCr
ATP-PCr Duration?
10-15 seconds
What is ATP-PCr used for?
To quickly restore ATP production
Where does ATP-PCr occur?
In the cytoplasm
PCr Rate Limiting Enzyme?
Creatine Kinase controls rate of ATP production; a negative feedback system
What does Creatine Kinase do?
Decrease ATP (Increase ADP) –> Increase CK Activity
Increase ATP –> Decrease CK Activity
How is ATP-PCr formed?
Phosphate stolen from Creatine and Attaches to ADP
PCr Byproducts?
Creatine and ATP
How much weight put on in first couple weeks because of Pcr?
6-8 lbs, mainly water weight
What happens when exercising with PCr?
More creaine means PCr will be raised higher, allowing the duration to last longer while slowly depleting ATP as well.
What type of reaction is the Glycolytic System?
Anaerobic?
Glycolytic System ATP yield
2-3 mol ATP / 1 mol Substrate
Glycolytic System Duration
15s - 2 min (1 min - 2 min in healthy individuals)
Glycolytic System Breakdown?
Breakdown of Glucose (2 ATP) or Glycogen (3 ATP) via Glycolsys
How many enzymes involves in Glycolytic System?
10-12 Enzymes
Glycolysis Rate Limiting Enzyme?
Phosphofructokinase (PFK)
What does Phosphofructokinase do?
Decrease ATP (Increase ADP) –> Increase PFK Activity
Increase ATP –> Decrease PFK Activity
Regulated by products of Krebs Cycle
By products of Glycolytic System?
2-3 ATP
2 Pyruvate (Aerobic Continues ON)
2 Lactate + H+ (anaerobic)
What are the fates of Lactate?
Taken into Mitochondria
Release from cells to be used by other cells
Release from cell and taken up by liver sent through gluconeogensis
Pros of Glycolysis?
Allows muscles to contract when O2 is limited
Permits shorter-term, higher-intensity exercise than oxidative metabolism can sustain
Cons of Glycolysis?
Low ATP yield, inefficicent use of substrate
Lack of O2 converts pyruvic acid to lactic acid
H+ impairs glycolysis, muscle contraction
Why do we produce Lactate?
Produced to allow NAD to be recycled, allowing glycolysis to continue.
Aerobic Energy Production begins with ATP production from….
Fats
What kinda of reaction is Oxidative Metabolism?
Aerobic
Oxidative Metabolism - ATB Yield
Per Glucose: 32-33 ATP
Per FFA: 100+ ATP
Oxidative Metabolism Duration
Steady supply for hours
How complex is Oxidative Metabolism?
Most complex of three bio-energetic systems
Where does Oxidative Metabolism occur?
Occurs in the Mitochondria, not cytoplasm
Krebs Cycle First Step?
1 Molecule Glucose = 2 Acetyl - CoA
1 Molecule Glucose -> 2 Complete Krebs Cycles
Kreb Cycle Produces
2 Acetyl-CoA -> 2 GTP -> 2 ATP
NADH, FADH, H+
Kreb Cycle; What of too many H+ in cell?
Too Acidic
Kreb Cycle; Where is H+ moved to?
Electron TRansport Chain
Kreb Cycle: H+ and Electrons carried to and how?
ETC via NADH, FADH molecules
What happens as H+ and electrons travel down the chain?
H+ combines with O2 (Neutralized, forms H20)
Electrons + O2 Help Form ATP
ETC: ATP per NADH?
2.5
ETC: ATP per FADH?
1.5
Total ATP Yield from Aerobic Breakdown of Carbohydrates?
1 Glucose = 32 ATP
1 Glycogen = 33 ATP
Rate Limiting Enzyme for all Oxidative Cycles?
Isocitrate Dehhydrogenease
Similar to PFK for Glycolysis. Inhibited by ATP, Activated by ADP. Regulates Krebs and ETC
FInal byproducts of aerobic CHO Metabolism?
ATP, H20, CO2
Other byproducts is recycled and used in next Kreb cycle turn.
Fat Metabolism Basic Information
Features Triglycerides: Major Fat Energy Source
Fat Metabolism: What are Triglycerides broken into?
1 Glycerol and 3 FFAs
Lipolysis carried out by lipases
Yield for Fat Metabolism?
Yields ~3 to 4 times more ATP than Glucose.
Is Fat Metabolism slower than Glucose Oxidation?
Yes
How is Fatty Acid Transported into the Mitochondria?
By using membrane transporter to enter the muscle cell where it is activated. Combines with carnitine to enter the mitochondria.
What is Beta Oxidation?
Process of converting FFAs to Acetyl-CoA before entering Krebs Cycle
Cost of Beta Oxidation to start?
2 ATP
Beta Oxidation: How much does 16-carbon FFA yield?
8 acetyl-CoA
Beta Oxidation: How much does 1 glucose yield?
2 acetyl-CoA
Beta Oxidation: What does Fat Oxidation requires?
Requires more O2 but yields far more ATP later.
Total ATP yield from Oxidation of 16 carbon fatty acid?
116 ATP
Beta Oxidation Rate Limit?
Limited by FFA Availability in musclce and Kreb’s Speed
All three Energy Systems interact for all activities but…
not one system contributes 100% but one system often dominates for a given task.
Byproducts of one system can…….
affect another systems function. Citrate produced in the Krebs cycle can inhibit PFK and slow glycolysis sparing muscle glycogen.
Order of Maximal Rate of ATP Generation?
Fat Oxidation < CHO Oxidation < Glycolysis < PCr
Order of Maximal Available Energy?
PCr < Glycolysis < CHO Oxidation < Fat Oxidation
Oxygen Consumption Abbrevition?
VO2 - Volume of Oxygen Consumed
Rate of Oxygen Consumed by the body
Typically reported as an amount per minute.
Absolute Oxygen Consumption
Oxygen consumed per min (L/min)
Relative Oxygen Consumption
Oxygen consumed per minute relative to body mass (ml/kg/min)
VO2 Max
(Plateau) Max rate of oxygen consumption
Point at which O2 consumption doesn’t increase with further increase in intensity
VO2 Peak
(No Plateau)
Highest measurement of VO2 with no observable plateau. They could drop off after they reach the peak.
How much Relative VO2 Max consumed depends on Ab. VO2 and Body Mass. How do you know if you have a good amount burned?
The individual who burns a higher amount per ml/kg/min.
VO2 Max Norms for Average Fit
Male - 45 ml/kg/min
Female - 40 ml/kg/min
VO2 Max Norms for Elite
Male - >70 ml/kg/min
Female - >60 ml/kg/min
VO2 Max for Couch Potato
= 30 ml/kg/min
VO2 Max for End Stage COPD
~15 ml/kg/min
Order from highest to lowest VO2
Running
Cycling
Cross Country Skiing
Cross Country Skiing
Running
Cycling
What is the Lactate Threshold (LT)?
Point/Intensity at which blood lactate accumulation increases markedly.
Lactate production rate > Lactate Clearance Rate.
Lactate Threshold Interaction between
Aerobic and Anaerobic Systems. Formally called the anaerobic threshold.
Measure of anaerobic threshold.
Lactate Threshold usually expressed as ..
percentage of VO2 Max
Lactate Threshold for Training and Untrained
Untrained - 55-65% of VO2 Max
Trained - 80-90% of VO2 Max
How much can VO2max increase in untrained?
15-20%
Training Effects on Vo2 MAx and LT affected by
Genetics (Amount of Type I)
Weight at Start of Training
Initial Fitness
Causes of increase for VO2max and LT
Increase Oxidative Enzymes Increase Mitochondrial Content and Density Increase Capillary Density Increase Myoglobin Content Conversion of Type IIx to Type IIa
Lactate threshold can increase to
90% of VO2 Max
Causes of increases for Lactate?
Increase Oxidative Capacity (Increase oxidative enzymes and increase mitochondrial content and density)
Increase number of transporter around body
PhosphoCreatine Alternative Name
Creatine Phosphate
Glycolysis Alternative Name
Anaerobic Glycolysis
Oxidative Alternative Name
Aerobic Metabolism
PhosphoCreatine Substrate/Fuel Entering Pathway
Phosphocreatine
Glycolysis Substrate / Fuel Entering Pathway
Glucose
Glycogen
Oxidative Substrate / Fuel Entering Pathway from Glycolysis
Pyruvate/Lactate
Acetyl CoA, NADH
Oxidative Substrate / Fuel Entering Pathway from Beta Oxidation
Acetyl CoA
NADH & FADH
PhosphoCreatine Relative Speed of ATP Production
Fastest
Glycolysis Relative Speed of ATP Production
~ 2 Times slower the PCr
Oxidative Relative Speed of ATP Production
4-7 Times Slower than PCr
Phosphocreatine By-Products
ATP
Creatine
Glycolysis By-Products
ATP
Pyruvate & NADH/Lactate + H+
OxidativeBy-Products
ATP
H20
CO2
Recycled Intermediate
Phosphocreatine Location of Pathway Within Cell
Cytosol
Glycolysis Location of Pathway Within Cell
Cytosol
Oxidative Location of Pathway Within Cell
Mitochondria
PhosphoCreatine Time Limit
~10-15 seconds
Glycolysis Time Limit
~1-2 minutes
Oxidative Time Limit
Hours
PhosphoCreatine Control Of Rate
Increase Rate means Decrease ATP
And Vice Versa
Glycolysis Control of Rate
Increase Rate means Decrease ATP
And Vice Versa
Oxidative Control of Rate
Increase Rate means Decrease ATP
And Vice Versa
PhosphoCreatine Rate Limiting Enzyme
Creatine Kinase
Glycolysis Rate Limiting Enzyme
Phosphofructokinase
OXidative Rate Limiting Enzyme
Isocitrate Dehydrogenase
