Endocrine response to Resistance training Flashcards
What does endocrine refer to?
relating to hormone secreting glands
The whole system is complex information signalling system - slow then nervous system but has longer lasting effects
How do the exo and endocrine systems differ?
endocrine uses glands rather than ducts
Hormone definition
a regulatory substance produce in an organism and transported to biological tissue/fluids to stimulate a specific action in cells/tissues
Where do endocrine hormones act?
travels in circulation to another part of the body
Where do autocrine hormones act?
on the cell they are produced by
Where do paracrine hormones act?
on cells adjacent to production cell
What is hormonal amplification?
hormones only being released after being triggered by another hormone
at each stage the production is amplified
What are the 3 forms of hormone?
Steroid
Peptide
Amine
What are steroid hormones made of and how do they work?
cholesterol
diffuse through cell membrane & attach to receptor within cell
eg Testosterone, Estrogens, Cortisone
What are peptide hormones made of and how do they work?
multiple amino acids
attach to receptor on cell membrane
eg insulin IGF, growth hormone
What are amine hormones made of and how do they work?
single amino acids
attach to receptor on cell membrane
eg Epinephrine, adrenaline noradrenaline
How do steroidal hormones work?
enter cell
bind to receptor in nucleus/cytoplasm
triggers mRNA formation
mRNA directs protein synthesis in cytoplasm
How do non-steroidal hormones work?
bind to receptor on cell membrane
adenylate cyclase activated within cell
cAMP formed
cAMP activates protein kinases which produce cellular changes/hormonal effects
Which hormones are stored and where?
peptides & amines stored in vesicles
steroids released once produced
How does cellular water increase (therefore blood water decrease) effect hormone delivery?
amplifies endocrine effect from blood hormones
How does blood flow re-distribution effect hormone delivery?
more hormones delivered to working muscles
^ CO increases hormone clearance from other tissues
What % of testosterone is produced where in men?
95% leydig cells in testes
5% adrenals
Where is testosterone produced in females?
ovaries & adrenals
Growth hormone & IGF are more important anabolic hormones
What hormones are apparent before resistance training?
adrenaline and noradrenaline
What hormones are apparent during resistance training?
adrenaline, noradrenaline, Growth hormone & testosterone
What hormones are apparent after resistance training?
Growth hormone, testosterone, IGF-1 & insulin (nutrition mediated)
How does testosterone work?
T diffuse across sarcolemma of muscle fibre
binds with receptor
hormone-receptor complex exposes transcriptional units in nucleus
What are base testosterone levels for each gender?
Male 10-35 nmol.L-1
Female <3.5
what is the acute effect of testosterone on muscle tissue?
stimulates neurotransmitter production & calcium release both increase force production
Where is growth hormone secreted from?
Pituitary gland
Where does GH target?
bone, immune cells, skeletal muscle, fat cells & liver cells
what does GH targeting the liver do?
stimulates IGF production
What are basal GH levels like in a normal day
pulsations throughout day highest during sleep
in women GH & exercise responses vary w/ menstrual phase
What is the acute GH response to exercise
exercise (blood lactate) stimulates GH production
conc peaks after exercise
only binds with active muscles
What does IGF-I do?
^ glucose use ^ glylcogen synthesis ^ protein synthesis stimulate cartilage decrease lipolysis
how can ‘anabolic hormones’ acute responses be stimulated to increase
Heavy resistance
large muscle group exercises
shorts rest intervals
