Chapter 4: Endocrine Responses to Resistance Exercise Flashcards
complex signaling system in the body that produces hormones to regulate essential functions and support exercise demands and recovery
endocrine system
the endocrine system is important in strength and conditioning due to its critical role in the development of?
training periodization
describes the physiologic changes your body goes through as it responds to stress, occurs through stages
general adaptation syndrome
what is the ultimate goal with the general adaptation syndrome?
promote adaptations and recovery while managing fatigue and stress
increased resistance to stress
adaptation
increased resistance to exercise stress
training adaptation
reapplication of an increased stress
progressive overload
the study of interactions between the nervous and endocrine systems
neuroendocrinology
the study of the connection between the neural, endocrine, and immune systems in the remodeling process of muscle
neuroendocrine immunology
_____ are intimately involved with protein synthesis and degradation mechanisms that are part of muscle adaptations to resistance exercise
hormones
anabolic hormones
hormones that promote tissue building
examples of anabolic hormones
testosterone
growth hormone
IGF-1
insulin
catabolic hormones
hormones used to degrade cell proteins
examples of catabolic hormones
cortisol
epinephrine
norepinephrine
progesterone
what is another important action of anabolic hormones in the building of tissues?
block the negative effects on protein metabolism of catabolic hormones
increased performance following a period of training stress
supercompensation
binding sites on receptors that allow substances other than hormones to enhance or reduce the cellular response to the primary hormone
allosteric binding sites
a receptor partially interacts with other hormones
cross reactivity
reduced ability of a hormone to interact with a receptor
downregulation
maximal amount of protein added to a muscle fiber is an example of what type of downregulation? acute or chronic
acute
what is a primary example of chronic downregulation?
type II diabetes: overstimulation causes insulin resistance
increased ability of a hormone to interact with a receptor
upregulation
three main categories of hormones
steroid
polypeptide
amine
most prominent amine hormones involved with exercise
catecholamines
class of hormones including testosterone, cortisol, and estradiol that can diffuse across the sarcolemma and bind with its receptor to form a HRC
steroid hormones
class of hormones made of amino acid chains including growth hormone and insulin that bind to membrane receptors and act via secondary messengers inside the cell
polypeptide hormones
true or false: hormone responses are tightly linked to the characteristics of the resistance exercise protocol
true
despite having lower levels, why do women better use the amount of testosterone present following a resistance exercise stimulus?
the androgen receptors in females are dynamic and have a faster upregulation than men
primary male androgen that is anabolic AND anti catabolic and binds with skeletal muscle tissue
testosterone
why is ingesting protein and carbohydrates before a workout important in terms of testosterone?
upregulates skeletal muscle androgen content
what has been shown to increase growth hormone response to exercise?
birth control
normal fluctuations in hormone levels throughout the day
diurnal variations
true or false: it is possible to manipulate the endocrine system with resistance training in order to improve performance
true
order of anabolic hormone release in response to resistance exercise
1st: testosterone
2nd: growth hormone
3rd: ICF-1
2 main neuroendocrine hormones
testosterone and growth hormone
what is the primary hormone that influences the nervous system and how does it accomplish this?
testosterone, increases neurotransmitters to increase force production potential (more motor units recruited)
the amount of hormone released after an exercise depends on what 3 things?
amount of muscle tissue activated
load
rest interval
would a back squat or a bicep curl create more hormone secretion?
squat (more muscle tissue activated)
true or false: testosterone has a greater neuromuscular response than growth hormone
true
__________ increases the concentrations, number of receptors, and membrane/receptor sensitivity of anabolic hormones
heavy resistance training
catabolic > anabolic actions
downregulation of receptors
overtraining
when are hormone receptor interactions greatest?
when exercise acutely increase blood concentrations of the hormones
what do acute hormonal secretions tell the body about physiological stress?
amount and type
when are hormone receptors less sensitive?
closer to max genetic potential
chronic elevated levels due to disease
exercise prescription mistakes
which hormone promotes the release of growth hormone?
testosterone
exercising with large muscle groups will result in an acute increase in the concentration of what hormone?
testosterone
how can we maximize testosterone concentration with resistance training?
short rest periods
heavy resistance
moderate to high volume
large muscle groups
more free testosterone is present following resistance training in men or women?
men
on average, how much more testosterone do men have compared to women?
15-20x more
true or false: there is a significant difference in testosterone levels in prepubescent males and females
false
why is strength similar for males and females until the age of 14?
adaptations are neuromuscular, rather than from muscular hypertrophy
at what point in life can we start to see significant changes due to testosterone?
puberty
which hormone stimulates IGF-1 secretion?
growth hormone
when do growth hormone secretions increase?
at night
what can we do to enhance growth hormone secretion?
get adequate sleep
how can we maximize growth hormone concentration with resistance training?
short rest periods
moderate to heavy loads
true or false: men have higher levels of growth hormone in their blood
false
why do the concentrations and responses of growth hormone vary in women more than men?
menstrual cycle
growth hormone concentrations are highest during what phase of the menstrual cycle?
1st phase: menstruation
prior to ovulation
IGF levels in the bloodstream are acutely increased how many hours after exercise/growth hormone secretion?
8-24 hours after
which hormone has been shown to stimulate the secretion of its own binding proteins?
IGF-1
IGF-1 in muscle tissue is referred to as?
mechano growth factor
protein and carbohydrate supplementation before and after training increases the concentration of what hormone?
IGF-1
process of turning blood sugar into stored glycogen
glycogenesis
hormone that is anabolic, released after you eat food, moves glucose out of the bloodstream, and increases glycogen stores
insulin
condition due to low blood glucose levels that can cause dizziness, sweating, and/or nausea following physical activity
hypoglycemia (insulin shock)
if an athlete is experiencing a hypoglycemia attack, what should we tell them to do?
lie down with feet up
drink a sugar drink
glucocorticoid that is catabolic and anti anabolic, promotes protein breakdown, and conserves blood glucose
cortisol
do cortisol levels increase before, during, or after exercise?
during
why is training that stimulates acute cortisol release necessary for the remodeling process?
keeps net muscle protein synthesis positive
how can we maximize cortisol concentration with resistance training?
high volume
short rest periods
large muscle groups
what level of chronically high cortisol can have adverse catabolic effects and may indicate overtraining?
> 800 nmol/L
what are the three main catecholamines?
epinephrine
norepinephrine
dopamine
catabolic hormones that increase energy availability/blood glucose levels by blood vessel vasodilation and anabolic hormone release
catecholamines
catecholamine release reflects the _____ of the exercise
demand
how can we maximize catecholamine concentration with resistance training?
high intensity
short rest periods
high heart rate
why is it so important to create variability within training protocols?
variability allows the adrenal gland to recover, prevent chronic cortisol secretion, and symptoms of overtraining
how can chronic levels of cortisol affect the immune system?
may cause immunosuppression
catecholamine that increases cardiac output, blood sugar, glycogen breakdown, and fat metabolism
epinephrine
catecholamine that has the same properties of epinephrine but is also a vasoconstrictor
norepinephrine
