![• Pyka et al. (1992) measured serum GH responses to a standardized
circuit of resistance exercise in 12 young subjects (6 men and 6
women; 27 +/- 1.6 yr old) and in 11 elders (6 men and 5 women; 72
+/- 0.8 yr old). Initial assessment of strength [1 repetition maximum
(1RM)] was made of 12 muscle groups using Nautilus equipment.
One week later, subjects carried out the exercise protocol, 3 sets of 8
repetitions for each of the 12 exercises, at 70% of predetermined
1RM values. Venous blood was drawn at baseline, after each
exercise, and every 2 min during 10 min of recovery. It has found
that Exercise increased GH in both groups, but peak values (14.9 +/-
3.5 micrograms/L in young; 2.44 +/- 0.6 micrograms/L in old) were
significantly greater in the young subjects. In the young subjects,
GH responses were nonsignificant at 60% and increased
progressively at 70% and 85% of 1RM. (3)
Shalu Thariwal](https://image.slidesharecdn.com/effectofexerciseonendocrinesystem-200609123644/85/Effect-of-Exercise-on-Endocrine-System-39-320.jpg)
Effect of Exercise on Endocrine System
- 1. Effect of Exercise on Endocrine System Presented by: Shalu Thariwal
- 2. Endocrine system • Pituitary gland • Pineal gland • Thyroid • Parathyroid • Adrenal • Thymus • Pancreas • Gonads • Hypothalamus Shalu Thariwal
- 4. Endocrine system organization • Endocrine system consists of a) Host organ b) Hormone c) Target organ Ductless gland – release hormones into the blood to fulfill cellular functions. Target cell receptors occur either on the plasma membrane and in the cell’s interior(steroid hormones). Shalu Thariwal
- 5. Types of Hormones • Steroid Hormones: – Structure similar to cholesterol –, fat soluble, Can pass through cell membranes – Direct gene activation for ex-Cortisol, Aldosterone, Estrogen, Progesterone, Testosterone • Non-steroid Hormones: – Protein/peptide or amino acid- derived, soluble in blood – Cannot pass through cell membrane – Second messenger activation for ex- Thyroid Hormones,Epinephrine/Norepinephrine Shalu Thariwal
- 6. Hormone target cell specificity • Hormones modify intracellular protein synthesis rate • Stimulate DNA • Change rate of enzyme activity • Alters plasma membrane transport via a 2nd messenger system • Induce secretion Shalu Thariwal
- 7. Feedback Control of Hormone Secretion Negative Feedback: Release of the hormone has a negative effect on its own release, this prevents oversecretion of the hormone. The controlled variable is often the activity of the target tissue. As a result, negative feedback kicks in only when the target tissue displays an appropriate level of activity. Positive feedback: Rare, but in some instances the biological action of a hormone causes additional secretion of the hormone. This occurs until an appropriate concentration is reached, at which point negative feedback is initiated. Ex- Estrogen stimulates secretion of luteinizing hormone (LH), which acts on the ovaries to stimulate more estrogen, etc. Shalu Thariwal
- 8. Hormone-Receptor Binding Upregulation: target cells form more receptors in response to increasing hormonal levels Downregulation: caused by prolonged exposure to high hormone concentrations, causes a desensitizing of target cells so that they respond less vigorously to hormonal stimulation Shalu Thariwal
- 10. Glands, their secretions ,effects • Shalu Thariwal Host glands Hormone Effects Control Hypo and hypersecreti on Exercise effects on hormon es Anterior pituitary Growth hormone(G H) tissue growth, mobilize fatty acid Hypothalami c releasing factor (GHRF) hypo: dwarfism hyper:gigantis m,acromegaly increase with increasing exercise Thyrotropin (TSH) stimulates and production of thyroxine hypothalamic TSH releasing factor hypo: cretinism, myxedema hyper:grave's disease increase Corticotropi n (ACTH) production and release of cortisol, aldosterone and adrenal hormones. hypothalamic ACTH releasing factor hyper: cushing syndrome unknown
- 11. Gonadotro pic (FSH,LH) production of estrogen and progesteron e and testosterone by testes. hypothala mic FSH, LH releasing factor hypo: failure of sexual maturatio n no change Prolactin inhibits testosterone and mobilize fatty acid hypothala mic PRL inhibiting factor hypo: poor milk production hyper: galactorrhe a, ceases menses, impotence in males increase Endorphins blocks pain stress - increase Shalu Thariwal
- 12. Posterio r pituitar y vasopressi n controls water exceretion by kidneys hypoth alamic secreto ry neuron s hypo: diabetes increas e oxytocin stimulates muscles in uterus and breast, birth and lactation same - - Adrenal cortex cortisol, corticosteron e promotes fatty acid, protein catabolism, blood sugar, ACTH, stress hypo: Addison's disease hyper: cushing's syndrome increase Aldosterone retention of Na, K and water renin, angioten sin hypo: Addison's disease, hyper: aldosteronism increase Shalu Thariwal
- 13. Adrenal medulla epinephrin e and nor epinephrin e symp. activity, inc. glycogen catabolism, fatty acid release hypotha lamic, sym. nerves hyper: HTN increase Thyroid Thyroxine(T 4) triiodothyro nine(T3) stimulates metabolic rate TSH hypothyroidism, hyperthyroidism increase Pancreas Insulin dec. blood glucose, promotes fatty acid transport into cells plasma glucose level hypo: diabetes hyper: hypoglycemia decrease Glucagon release of glucose from liver, lipid metabolism same hypo and hyperglycemia increase Shalu Thariwal
- 14. parathy roid parathom one inc. blood calcium, dec. blood phosphate plasma calcium conc. hypocalce mia, hypercalc emia increase Ovary Estrogen, progesteron e Egg production, secondary sexual characteristics - - - Testes Testosteron e Sperm production, secondary sexual characteristics - - - Kidney Renin Increases metabolic rate, promote calcium depostion - - - Shalu Thariwal
- 15. Growth hormone Effects of Growth Hormone • Increased amino acid, transport across cell membranes • Increased protein synthesis • Increased utilization of fatty acids Increased fat breakdown • Increased availability of glucose and amino acids Decreased glucose utilization • Decreased glycogen synthesis Increased collagen synthesis and Stimulate cartilage growth • Increased retention of Nitrogen, Sodium, Potassium, and Phosphorus Enhanced immune function • Increases renal plasma flow, filtration, and hypertrophy Shalu Thariwal
- 16. GH 1.What Stimulates Growth Hormone Secretion? • Decreased blood glucose • Decreased blood free fatty acids • Starvation, protein deficiency, Trauma, stress, excitement • Exercise • Testosterone, estrogen, Deep sleep 2.What Inhibits Growth Hormone Secretion? • Increased blood glucose • Increased blood free fatty acids • Aging,Obesity Shalu Thariwal
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- 18. GH • Short term exercise – sharp rise in GH • Stimulates insulin like growth factors(by liver) which maintain GH effect. • Maintain glucose level by mobilizing free fatty acids- good performance in prolonged exercise. • Researches has shown that GH in sedentary individuals maintains at higher level for several hours after recovery. Shalu Thariwal
- 19. Regulation of Glucose Metabolism • Controlled by Five Hormones: Insulin, Glucagon, Epinephrine, Norepinephrine and Cortisol • During Exercise Blood Glucose is affected by three factors: – Liver release of glucose – Muscle uptake of glucose – Dietary intake of glucose Shalu Thariwal
- 20. Glucagon • Secretion Site: Pancreas • Action: Cause liver glycogen breakdown and glucose release to blood • Exercise Response: Positively correlated to exercise intensity, Effect of Chronic Exercise: at given intensity compared to untrained individual Shalu Thariwal
- 21. Insulin • Secretion Site: Pancreas • Action: Glucose uptake by muscle at rest, regulating blood glucose concentration • Exercise Response: Not released during exercise; receptors more sensitive, thus less insulin required • Effect of Chronic Exercise: No exercise response Shalu Thariwal
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- 23. Cortisol • Secretion Site: Adrenal Cortex • Action: Increase in Protein Catabolism, Increase blood amino acids for gluconeogenesis (making glucose from other substrates) • Exercise Response: Positively correlated to exercise intensity (>80% max effort) but only acts during first 30-45 min • Short Duration Exercise: High intensity = Greater catecholamine release = Greater release of glucose from liver 40-50% increase in blood glucose Replenishes muscle glycogen stores • Long Duration Exercise: Glucose production = demand Liver glycogen stores are a limiting factor, Blood glucose concentration may decrease • Glucagon/Cortisol gluconeogenesis Shalu Thariwal
- 24. Regulation of Fat Metabolism • Controlled by Five Hormones • Fat Metabolism is needed – When exercise depletes glycogen stores (long duration exercise) – When diet depletes glycogen stores (fasting, low CHO dieting, etc.) Shalu Thariwal Insulin Cortisol Epinephrine Nor- epinephrine GH
- 25. Exercise training Hormones Training response GH No effect on resting values Thyrotropin No known training effect ACTH Increased Prolactin Some evidences- lowers resting values FSH,LH, Testosterone In females – low values Testosterone increased in males in long term resistance training. T3, T4 Increased turnover during exercise. Aldosterone No effect Cortisol Slight elevations during exercise Shalu Thariwal
- 26. Epinephrine and norepinephrine Decreased at rest and then normal at absolute intensity exercise. Insulin Decrease during exercise and greatly reduced with training. Glucagon Smaller increase Renin and angiotensin No effect Vasopressin Slight reduced Oxytocin No research available Shalu Thariwal
- 27. • Alghadir et al, (2015)purpose of this study was to evaluate the effect of 4 weeks moderate aerobic exercise on outcome measures of saliva stress hormones and lactate levels in healthy adult 15 to 25 age. • moderate intensity for 4 weeks, three times per week. • It was found that after 4 weeks of exercise, there were significant increases in cortisol, free testosterone levels, and LDH activity along with a significant decrease in the ratios between testosterone and cortisol levels.(1) Shalu Thariwal
- 28. Wheelel et al.(1984)-Runners show significant decrease in testosterone 640 660 680 700 720 740 760 780 800 820 testosterone control runners Shalu Thariwal
- 29. 0 500 1000 1500 2000 2500 3000 3500 rest 60 65 70 75 80 X axis – VO2 max Y axis – plasma norepinephrine m/l untrained trained Shalu Thariwal
- 30. 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 Category 1 Category 2 Category 3 Category 4 Series 1 Series 2 Shalu Thariwal
- 31. Effect on growth hormone • Gibney et al.(2007) study the effects of the GH/IGF-I axis on exercise physiology. Measures of exercise performance including maximal oxygen uptake and ventilatory threshold. Administration of supraphysiological doses of GH to athletes increases fatty acid availability and reduces oxidative protein loss, particularly during exercise, and increases lean body mass. There is evidence that exercise performance and strength are improved by administration of GH and testosterone in combination to elderly subjects.(2) Shalu Thariwal
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- 33. Fig: Schematic representation of the possible association between the GH response to exercise and lipolysis. Shalu Thariwal Endocrine Reviews, Volume 28, Issue 6, 1 October 2007,
- 34. Acute effects of exercise • Moderate exercise: boosts immune functions and host defenses mechanism for several hours. • Increase natural killer cell activity, inactivates virus and tumor cells. • Exhaustive exercise: it severely blunts the body’s defense mechanism. • Increase temp, increase stress related hormones. Shalu Thariwal
- 35. Long term effects of exercise • Limited evidences that shows aerobic exercise training effects on immune functions positively in young and old age. Shalu Thariwal
- 37. Cont…. 2 main hormones that affect by resistance training • GH • Testosterone • A single training session elicits a sharp rise in serum testosterone and decrease cortisol. • Catecholamines also release. • Exercises – dead lifts, squats, heavy resistance exercise- 85 ton 95% 1 RM. • Long term effect- increase resting testosterone levels and improves strength. Shalu Thariwal
- 39. • Pyka et al. (1992) measured serum GH responses to a standardized circuit of resistance exercise in 12 young subjects (6 men and 6 women; 27 +/- 1.6 yr old) and in 11 elders (6 men and 5 women; 72 +/- 0.8 yr old). Initial assessment of strength [1 repetition maximum (1RM)] was made of 12 muscle groups using Nautilus equipment. One week later, subjects carried out the exercise protocol, 3 sets of 8 repetitions for each of the 12 exercises, at 70% of predetermined 1RM values. Venous blood was drawn at baseline, after each exercise, and every 2 min during 10 min of recovery. It has found that Exercise increased GH in both groups, but peak values (14.9 +/- 3.5 micrograms/L in young; 2.44 +/- 0.6 micrograms/L in old) were significantly greater in the young subjects. In the young subjects, GH responses were nonsignificant at 60% and increased progressively at 70% and 85% of 1RM. (3) Shalu Thariwal
- 40. • Tremblay et al. (2004) purpose of this study was to determine the acute anabolic and catabolic hormone response to endurance and resistance exercise bouts of equal volume in subjects with differing training status. Twenty-two healthy men were recruited who were either resistance trained (n = 7), endurance trained (n = 8), or sedentary (n = 7). Three sessions were completed: a resting session, a 40-min run at 50-55% maximal oxygen consumption, and a resistance exercise session. Blood samples were drawn before exercise and 1, 2, 3, and 4 h after the start of the exercise. Androgens increased in response to exercise, particularly resistance exercise, whereas cortisol only increased after resistance exercise. After an initial postexercise increase, there was a significant decline in free and total testosterone during recovery from resistance exercise.(4) Shalu Thariwal
- 41. References • Alghadir AH, Gabr SA, Aly FA. The effects of four weeks aerobic training on saliva cortisol and testosterone in young healthy persons. Journal of physical therapy science. 2015;27(7):2029-33. • ames Gibney, Marie-Louise Healy, Peter H. Sö nksen, The Growth Hormone/Insulin-Like Growth Factor-I Axis in Exercise and Sport, Endocrine Reviews, Volume 28, Issue 6, 1 October 2007, Pages 603–624, https://doi.org/10.1210/er.2006-0052 • Pyka GI, Wiswell RA, Marcus RO. Age-dependent effect of resistance exercise on growth hormone secretion in people. The Journal of Clinical Endocrinology & Metabolism. 1992 Aug 1;75(2):404-7. • Tremblay MS, Copeland JL, Van Helder W. Effect of training status and exercise mode on endogenous steroid hormones in men. Journal of Applied Physiology. 2004 Feb;96(2):531-9. • Katch and katch. Essentials of exercise physiology. 4th ed. Shalu Thariwal
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Editor's Notes
- #33: Lipolysis, estimated from the rate of appearance of glycerol (top panel), and oxidative protein loss, estimated from leucine oxidation (bottom panel) at rest and during and after exercise in endurance-trained athletes (n = 6), before and after 4 wk of treatment with GH, 0.066 mg/kg·d. *, P < 0.05 for the change from baseline. [Adapted from Refs. 182 and 190 with permission. Copyright 2003 and 2006, The Endocrine Society.]