Unit 3 Exam Flashcards
two mechanisms of strength gain
hypertrophy and atrophy
neural adaptations
which mechanisms are responsible for early gains in strength
neural adaptations (learning effect)
4 potential neural adaptions
synchronization of motor units
motor unit recruitment
motor nerve firing rates
removal of neural inhibition
2 additional neural factors
coactivation of antagonists and agonists
morphology of the neuromuscular junction
transient hypertrophy
occurs during or after a workout and disappears within hours
due to edema formation from plasma fluid
chronic hypertrophy
reflects an actual structural change in the muscles (long-term)
what type of training maximizes hypertrophy to induce muscle damage
eccentric training
the primary stimulus for chronic muscle hypertrophy
tension
recommended intensity for max hypertrophy
60% of 1RM
recommended intensity for muscular strength
50% of 1RM
how is muscle fiber hypertrophy accomplished
increase in # of myofilaments, # of myofibrils, sarcoplasm, and supporting connective tissue
current evidence for muscle fiber hyperplasia
unlikely in humans, but common in animals
only certain individuals under certain conditions
when does hypertrophy become a major factor contributing to strength gains
resistance training = increases protein synthesis
which muscle fiber type is most affected by immobilization
type I
what is the most common fiber type transition
type IIx to type IIa
how much protein is recommended immediately after resistance exercise
20-25g
daily RDA of protein to increase muscle mass
1.6g / kg of body mass
RDA is .8g / kg of body mass
resistance training for kids
safe under certain conditions
can gain both strength and mass
resistance training for the elderly
helps restore lost muscle mass
improves the quality of life and health
prevents falls
strengths due to neural adaptions
how does aerobic training influence the cardiovascular fick equation
increase VO2max = increase SVmax * HRmax * increase (a-v)O2 dif
how does aerobic training influence heart size
increases heart size
how does aerobic training influence SV
increase SV
how does aerobic training influence HR
max HR has no significant change
HR recovery is quicker
decrease resting HR
how does aerobic training influence cardiac output
untrained: 5 L/m rest; 20-25 L/m max
trained: 5 L/m rest; 40 L/m max
how does aerobic training influence blood flow to active and inactive muscles
increase capillary recruitment to active muscles
decrease blood flow to inactive muscles
how does aerobic training influence total blood volume
prevents any decrease in venous return as a result of more blood in the capillaries
increase in total blood volume
how does aerobic training influence blood pressure
decrease BP
SV of a trained individual
resting: 100 mL
max: 200 mL
cardiac output (Q) of a trained individual
resting: 5 L/m
max: 40 L/m
(a-v)O2 difference of a trained individual
resting: 5mL/100mL blood
max: 15mL/100mL blood
how does aerobic training influence pulmonary ventilation
decrease at submaximal
increase at max
how does aerobic training influence (a-v)O2 difference
increase because of the increase in O2 extraction
how does aerobic training influence fiber type
increase the size and # of type I fibers
how does aerobic training influence capillary supply
increase # of capillaries
how does aerobic training influence myoglobin
increase content by 75-80%
supports the increase of oxidative capacity
how does aerobic training influence mitochondria
increase size and #
how does aerobic training influence oxidative enzymes
increase activity with training
enhanced glycogen sparing
how does aerobic training influence VO2 max
increase 20-25%
resting is unchanged
how does aerobic training influence lactate threshold
increase to a higher % of VO2 max
decrease lactate production = increase lactate clearance
how does aerobic training influence RER
increases dependency on fat, decrease dependency on glucose
the gold standard for measuring anaerobic power
Wingate test
which metabolic pathway is most susceptible to adaption with anaerobic training
ATP-PCr
what limits exercise performance at altitude
reduced PO2
at what altitudes can performance be restored by acclimatization
low altitude (500-2000m)
how does O2% change with altitude
%O2 stays the same by PO2 decreases with an increase in altitude
how does acute exposure to altitude influence ventilation
increase ventilation (hyperventilation) increases pH
how does the pH change affect the oxyhemoglobin dissociation curve
shifts to the left
how does altitude influence oxygen transport
decrease alveolar PO2 = decrease in hemoglobin saturation
= decrease gas exchange at the muscle
how does acute altitude exposure influence plasma volume
short term decrease in plasma volume = increase in hematocrit
how does acute altitude exposure influence RBC count
increase RBC after weeks or months
long term increase in hematocrit
how does acute altitude exposure influence SV
decrease SV due to decrease plasma volume
how does acute altitude exposure influence HR
decrease HRmax due to decrease SNS responsiveness
increase overall HR
how does acute altitude exposure influence cardiac output
cardiac output increases
how does acute altitude exposure influence (a-v)O2 difference
increased
how does acute altitude exposure influence values for cardiac output, SV, and HR at the maximal level
everything is reduced at the maximal level
average time to acclimatize to moderate altitude
3 weeks
how does chronic exposure to altitude affect ventilation
increase ventilation at rest and during submaximal exercise
how does chronic exposure to altitude affect hematocrit
increase RBC and hematocrit
how does chronic exposure to altitude affect plasma volume
decreases then increase due to an increase in SV and Q
how does chronic exposure to altitude affect muscle CSA
cross-sectional area decreases
decreases muscle mass due to weight loss
how does chronic exposure to altitude affect the metabolic potential
decrease muscle metabolic potential
mitochondria and glycolytic enzymes decrease
oxidative capacity decrease
what is the best strategy to use for altitude living and training
live high and train low, passive acclimation and training not compromised by low PO2