Final (Lectures 8-10) Flashcards
What are the 3 main categories of hormones
amine, peptide, steroid
Give 2 peptide hormones
insulin, growth hormone
Give 2 amine hormones
epinephrine, norepinephrine
Give 2 steroid hormones
testosterone, estrogen
What are the 3 primary ways for endocrine gland stimulation
hormonal, humoral, neural
What factors influence hormone potency
Hormone half-life, binding (carrying) proteins, receptor concentration, receptor affinity, 1st pass effect in the liver, exposure
Endurance trained individuals show ____ rise in growth hormone levels at a given exercise intensity
less
What type of training increases the frequency and amplitude of growth hormone secretion
resistance training
Are epinephrine and norepinephrine levels higher or lower in trained individuals?
Lower
Which organ is cortisol released from
adrenal cortex of kidney
True or False: RT in men increases the frequency and amplitude of testosterone secretion, creating a favorable hormonal environment for muscular hypertrophy
True
Acute exercise _____ estrogen levels, chronic exercise _____ estrogen levels in women
increases; decreases
Under what conditions is testosterone increased
high volume training with <1 min rest intervals, heavy RT, activation of large muscle groups
What are two anabolic strategies known to be successful in increasing muscle size and strength
progressive resistance training and androgen supplementation
What are some risks of steroid use in men vs women
men: decreased sperm count, testicular atrophy, gynecomastia (non-cancerous increase of male breast tissue size)
women: facial hair, voice deepening, menstrual irregularities, clitoral enlargement, decreased breast tissue
How does caffeine improve performance (mechanism)
Facilitates use of fat as an exercise fuel instead of using up the body’s limited carbohydrate reserves
What is the proposed direct and indirect mechanisms of caffeine
direct: on adipose and peripheral vascular tissues
indirect: by epinephrine which inhibits adenosine receptors on adipocytes –> activates hormone-sensitive lipases to promote lipolysis
Even though caffeine is a potent diuretic, fluid loss is lessened when caffeine is consumed during exercise because:
1) catecholamine release in exercise greatly reduces renal blood flow
2) exercise enhances renal solute reabsorption and consequently, water conservation
True or False: Pangamic Acid (B15) increases the cell’s ability to use O2 and reduce lactate build-up
False, research has failed to show these purported benefits; illegal to sell
Erythropoietin (EPO) can increase which 2 substances by as much as 12%
hemoglobin and hematocrit
In what type of foods is L-carnitine found
meat and dairy products
What compound facilitates the influx of long-chain fatty acids into the mitochondrial matrix where they enter beta-oxidation during energy metabolism
L-carnitine
What foods does creatine come from
meat, poultry, fish
What are 2 main suggested roles of creatine supplementation
1) delay depletion of creatine phosphate
2) facilitate muscle relaxation and recovery from repeated bouts of intense, brief effort via faster ATP and CrP resynthesis
What substance completely counteracts the ergogenic effect of muscle creatine loading
caffeine
Warm up may improve physical performance due to increases in _____ and muscle and core _______.
blood flow; temperature
This type of reaction captures energy from the breakdown of energy-rich fuel molecules
catabolic
what are the 3 stages of catabolism
1) hydrolysis to simpler building blocks
2) conversion to simple intermediates such as acetyl CoA
3) oxidation of acetyl CoA to CO2
Name the 3 pathways of ATP production
phosphagen system
glycolytic metabolism
mitochondrial respiration
which pathway is the fastest way to regenerate ATP
phosphagen system (creatine phosphate)
what compound does glycolysis start with and what are the important products
begin with glycogen or glucose
products: pyruvate, NADH, ATP
what is the only macronutrient whose stored energy generates ATP anerobically
muscle glycogen
Does catabolism of CHO for energy or energy generation from fatty acid breakdown occur faster?
catabolism of CHO
What do persons with McArdle’s Disease not produce
produce minimal or no lactate with exercise
What deficiency do persons with McArdle’s Disease have
myophosphorylase deficiency
Where is 90% of glucose formed? 10%?
90%: liver 10%: kidneys
True or False: Glucose can be formed in the muscles
False; muscle lacks a few enzymes required for gluconeogenesis (pyruvate carboxylase, glucose 6-phosphate)
What are the main products of mitochondrial respiration
ATP, CO2, NADH, FADH
The production of ATP and water during the electron transport chain is called
oxidative phosphorylation
Approximately how many ATP molecules does one 6-carbon glucose yield
36 ATP
The breakdown of triacylglycerols by lipases to form glycerol and FFA
lipolysis
What is the process of breaking down FFA called
Beta oxidation
Approximately how many ATP molecules are generated from beta oxidation
460 ATP
What are the main amino acids oxidized in skeletal muscle
isoleucine, leucine, valine, glutamine, glutamate
The release of lactate from muscle into the circulation for uptake by the liver and conversion to glucose
Cori cycle
The release of alanine from the muscle into the circulation for uptake by the liver and conversion to glucose
Alanine cycle
The process of combining smaller molecules to form larger molecules using free energy
anabolism
What is the conversion of carbohydrates to fat called?
De Novo Lipogenesis
Where does De Novo Lipogenesis occur (organ) ?
Liver
True or False: Many studies have shown that net DNL is absent or contributes very little to overall fat deposition
True
Excess CHO causes ____ of body fat, despite not being ____ to fat
accumulation; converted
Can fat be converted into carbohydrates in humans?
No; we only have a pathway to convert carbohydrates to fat but not vice versa
What substrate do we utilize predominantly during low-intensity exercise?
lipid
What substrate do we utilize predominantly during increased exercise intensity?
CHO
When CHO becomes low, which substrates do we increase utilization of?
AAs and lipids
What is the Scandanavian regimen for CHO ingestion before exercise? What is the proposed purpose?
taper CHO wk before event –> 3 days before event increase CHO 10% –> no training day before event –> eat final meal 3 hrs before event
purpose: maximize glycogen stores in the body after “depriving” body of CHO during tapering phase
Which is true: 1) CHO in a drink increases the absorption of H2O by the small intestine 2) A drink’s electrolyte content increases CHO delivery to the body
1) CHO in a drink increases the absorption of H2O by the small intestine
Which is more beneficial in increasing blood glucose levels during and after exercise, solid or liquid CHO?
both are equally beneficial
How is protein in CHO beverage after exercise beneficial?
increases the rate of muscle glycogen synthesis
The inability to continue movement or exercise at a given intensity
Fatigue
The fatigue response does not occur until creatine phosphate declines to ___ of its original concentration
less than 50%
ATP concentrations remain steady or decline minimally during intense exercise to muscular fatigue. However, ADP ___ and CrP ____.
increases; decreases
Muscle fibers that are low in glycogen have greater concentration of ____ _____, which indicates increased metabolic strain
inosine monophosphate (IMP)
What metabolites increase as muscle metabolism increases and may be implicated in the development of fatigue?
ammonia, lactate, free protons (H+), Pi, ADP, IMP
True or False: Increased acidosis elicits a systemic response with increased ventilation and feelings of nausea that may contribute to fatigue via central mechanisms
True
What factors contribute to the reduced ability to depolarize and repolarize with repeated intense and rapid contraction?
- efflux of K+ (impairs ATPases necessary to restore Ca2+)
- the negativity of lactate
- diminished neuromuscular function
True or False: triglyceride utilization probably does not contribute to fatigue
True
What are the 4 stressors associated with exercise
Physiological, environmental, social/psychological, artificial (lab)
hormonal regulation of fuel use in exercise; regulation of body fluids during exercise; tissue adaptation to exercise
exercise endocrinology
cortisol increases or decreases during acute exercise
increases
may decrease protein loss during stress by inhibiting protein catabolism
HMB; some studies show positive effects, others show no effects
what does blood doping do
increases RBC count and hemoglobin levels by as much as 8-20%
what type of cells is L-carnitine found in
muscle cells
which energy system is crucial to the muscle’s ability to tolerate increased metabolic demand?
phosphagen system
at what intensity is there complete dependence on CHO catabolism
60-85% of VO2 Max
where are FFA molecules primarily taken from
the blood
does most of our body’s fat come from synthesis or diet?
diet
the energy provided by creatine phosphate and glycolysis that supplements mitochondrial respiration
oxygen deficit
accumulation of acidosis or lactate relates most to muscle and systemic symptoms of fatigue
accumulation of acidosis
what are 7 potential fatigue factors
hyperthermia, dehydration, muscle damage, CNS, electrolyte imbalances, decreased muscle glycogen, hypoglycemia
what are the 3 types of granulocytes
neutrophils, eosinophils, basophils
what are the 3 types of lymphocytes
T cells, NK cells, B cells
the study of the interactions of physical, environmental, and psychological factors on immune function
exercise immunology
what are the physiological stressors associated with exercise
increased oxygen demand, glucose & lipid consumption, lactate production, physical load on musculoskeletal system
what are the environmental stressors associated with exercise
temperature, pressure, humidity, circadian/seasonal variation, pollution
what are the social/psychological stressors associated with exercise
personal achievement, competition, parental/peer pressure, financial consequence
what are the artificial (lab) stressors associated with exercise
electrical shock, unnatural activity, compulsory participation
epinephrine increases or decreases with intensity
increases
what is the connection between epinephrine and cytotoxic T and NK cells
Epi is a potent beta-2 adrenergic agonist; cytotoxic T and NK cells have high numbers of beta-2 adrenergic receptors
how long does cortisol remain elevated after exercise
2 or more hours
what cell action does cortisol inhibit
inhibits T cell proliferation
what type of cell number increases with cortisol
increases neutrophil number
how much do leukocytes increase up to immediately post-exercise
increase 50-100%
how much do NK cells increase immediately post-exercise
150-300%
these cells are the initial line of defense against acute and chronic infections
natural killer cells
which antigenic markers do NK cells specifically express
CD16, CD56
who tend to have higher NK cell activity at rest
athletes than non-athletes
after long duration exercise (marathon running), NK cell concentration drops below pre-exercise levels, persisting 2-4 post-exercise
open window hypothesis
what is the j-curve and risk of upper respiratory tract infection
sedentary people have an average risk for getting sick, the moderate exerciser has a lower risk for getting sick, very high exercises have a very high risk for getting sick
does aerobic exercise or resistance training affect immune function
aerobic exercise
a systemic skeletal disease characterized by low bone mass and microarchitectural changes resulting in fractures
osteoporosis
what are the types of osteoporosis
type 1: post menopausal (loss of trabecular bone)
type 2: senile (loss of cortical and trabecular bone)
risk factors of osteoporosis
race: caucasian, asian
family history
female, fair, small boned, short stature, lean
sedentary life-style, immobilization, alcohol use, smoking
lack of calcium and vitamin D
estrogen and androgen deficiency
med use: glucocorticoids, anticonvulsants, excess thyroids
other chronic diseases: diabetes, RA
by what age is peak bone mass achieved
age 30
how much of bone mass is created by puberty
70%
what are the most common sites for fractures
spine, hip, wrist, ribs
with osteoporosis, the rate of ____ exceeds the rate of _____
resorption, formation
how much bone is loss every year after menopause
1-1.5%
what are estrogen’s actions to prevent osteoporosis
increases calcitonin levels, inhibiting resorption
inhibits parathyroid hormone
inhibits IL-6 which activates osteoclasts
the greatest osteogenic response
high strains, short duration, site- specific, daily repetitions
