ES - Neuroendocrine Pys. - Functions of Hormones Flashcards
Physiological functions of testosterone?
Anabolic and anti-catabolic (counter Cortisol’s effects).
Promotes amino acid incorporation into proteins and inhibits protein breakdown, stimulates growth and development and maintenance of male sex characteristics.
How does testosterone affect performance? (5)
- Increased testosterone provides indirect marker of motor unit activation and metabolic demands beyond hemostatic conditions.
- Nervous system development in long-term training by augmenting neural adaptations that occur for strength gains in highly trained str. and pwr. athletes.
- Influences protein synthesis during high-intensity aerobic exercise.
- Can interact w/ receptors on motor neurons, increase amounts of neurotransmitters, and influence structural protein changes; all of these interactions can enhance FORCE PRODUCTION POTENTIAL AND MASS OF THE INNERVATED MUSCLE.
- Important in monitoring for stress/fatigue, as well all the anabolic state of the athlete
Physiological functions related to exercise of Insulin-like Growth Factors 1 (IGF-1)
increase protein synthesis in cells.
Promote the anabolic effects of growth hormones.
How does IGF-1 affect performance?
increased muscle growth and development, as well as recovery.
Physiological affects of glucagon?
stimulate increase in blood glucose concentrations by stimulating breakdown of liver glycogen. Thus, providing glucose to be converted to ATP during exercise.`
Physiological functions of related to exercise of epinephrine
act as central motor stimulators and peripheral vascular dilators (increased cardiac output) and enhance enzyme systems and calcium release in muscle during strength and power exercises.
Increases: blood sugar and glycogen breakdown, and fat metabolism.
How does epinephrine affect performance?
can maintain force output throughout heavy resistance sessions.
Metabolic control
Response mechanisms fro testosterone, GHs, and IGFs)
Training protocols must be varied to allow adrenal gland to…
Engage in recovery processes and to prevent the secondary responses of cortisol, which can have negative effects on the immune system and protein structures.
If training isn’t varied, and continued stress is not keeps the adrenal gland activated, recovery is delayed.
Physiological functions of Growth Hormones (different forms of GH MAY do these things)
Decrease: glucose usage and glycogen synthesis
Increases: amino acid transport, protein synthesis, fatty acid usage, fat breakdown (lipolysis), avail. of glucose and amino acids, collagen synthesis, retention of N, Na, K, and phosphorus, renal plasma flow and filtration.
Enhances immune cell function.
Promotes renal hypertrophy.
Stimulates cartilage growth.
How do growth hormones affect performance?
Concentration increase during breath holding and hyperventilation, as well as hypoxia.
Breakdown of testosterones role in resistance training and its connection to ATP-PCr?
- when elevated, results in boys ability to increase muscle mass through protein synthesis.
- increased muscle mass aids in strength and power development.
- power production is rapid thereby being reliant on the ATP-PCr system.
Growth Hormone increases to stress depend on?
exercise selection and program design; level increase during short rest (1-min) and longer duration (10RM v. 5RM) and a high resistance.
Physiological function of Cortisol
Signal hormone for carb metabolism
Catabolic effects of converting amino acids to carbs (not using blood glucose), increasing levels of proteolytic enzymes (enzymes that breakdown proteins), inhabiting protein synthesis, and suppressing glucose-dependent processes (e.g. Gluconeogenesis and immune cell function).
Promote fat oxidation.
Affect of Cortisol on performance
Greater affect on Type II fibers b/c they have more protein than Type I, but could still cause degradation to Type I.
Mediates nitrogen-wasting effect w/ a net loss of contractile protein, resulting in muscle atrophy w/ associated reductions in force capability.
Chronic high concentrations may have catabolic affects.
Acute increases are helpful in remodeling utilized muscles, allowing for damaged protein removal from muscle; furthering muscle remodeling and enlargement.
Physiological function of insulin (4)
Reduces blood glucose by promoting glucose uptake by cells
Promotes glycogen storage
Suppressed fat oxidation and Gluconeogenesis
Involved in protein synthesis
Physiological function of thyroid hormones
Thyroxine (T4): stimulates glycolytic and oxidative metabolism and cell growth.
Physiological functions of beta-endorphin
Stimulates analgesia (painkiller)
Reduces fatigue
Increases glucose uptake
Effect of training modes and/or programming on testosterone secretion
Increases in response to increasing exercise demands, in which receptors either increase binding.
During resistance exercise and training, muscle androgen receptor content increases, allowing for testosterone usage to be enhanced.
Nutritional intakes before workout can cause unregulated skeletal muscle androgen content increase and are reason why consuming carbs and protein before workout is important.
Effect of training modes and/or programming on growth hormone secretion (***)
To see changes resulting fro resistance training, GH concentration needs to be measured over 2-24 hours to show whether changes occur.
Increases w/ resistance training
Effect of training modes and/or programming on IGF-1 secretion
take 8-24 hours for IGF to be produced and released by liver following stimulation by GH.
During resistance training, if concentrations are low, IGF-1 increase. If high, no change or decrease in levels.
Intake (significantly increases concentrations before calming down) or restriction (slightly increases concentration levels) of food influences resting IGF-1 blood concentrations
Effect of training modes and/or programming on cortisol secretion
Increases w/ resistance training, most dramatically w/ high volume, large muscle groups. and short rest.
Heavy 5RM: increased in men, no change in women.
Acute cortisol responses may reflect metabolic stress.
Choric cortisol response may be involved w/ tissue homeostasis regarding protein synthesis.
Effect of training modes and/or programming on catecholamines secretion
Heavy resistance training increases epinephrine during maximal exercise.
Decrease during low intensity, short duration resistant training.
