Pituitary–adrenal responses to arm versus leg exercise in untrained man (original) (raw)
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Trained versus untrained men: different immediate post-exercise responses of pituitary adrenal axis
European Journal of Applied Physiology, 1997
The hypothalamo-pituitary-adrenal axis is involved throughout the exercise-recovery cycle. Nevertheless, differences in hormone responses during early recovery between sedentary and endurance trained subjects are not well known. The aim of this preliminary study was to monitor plasma cortisol and adrenocorticotropic hormone (ACTH) concentrations both during and after the end of running exercise performed by four endurance trained adults (marathon men) compared to four sedentary subjects. Two parameters, i.e. intensity and duration, were changed on 4 consecutive days. The 1 st day (D 0) was spent in the laboratory: all blood samples were obtained at rest to determine diurnal variations of each hormone. On the following days (D 1-D 4) the subjects exercised: D1 and D2 brief (20 min), light (50% maximal heart rate HR max , D 1) or strenuous (80% HR max , D 2), D 3 and D 4 prolonged (120 min), light (D 3) or strenuous (D 4). In both groups, neither brief (D 1 , D 2) nor prolonged light exercise (D 3) induced any significant variation in plasma ACTH or cortisol concentrations. Plasma ACTH and cortisol concentrations increased only if the exercise was intense and prolonged (D 4). The training factor did not modify the intensity or duration thresholds for the activation of the pituitaryadrenocortical response to exercise in the conditions of our experiment. However, during immediate recovery from the four exercise regimens, the plasma ACTH concentrations of the marathon men were constantly above the values of the sedentary subjects, although plasma cortisol concentration remained similar in both groups. As an indirect means of evaluating the relationships between ACTH and cortisol we compared the areas under the cortisol and ACTH curves (AUC) from 0.5 to 3.5h during recovery from D 1 to D 4 compared to D 0 at the same time. Cortisol AUC were similar in the sedentary subjects and marathon men although the ACTH AUC were different in the sedentary subjects and marathon men, suggesting a change in the pituitaryadrenal relationship at some yet indeterminate level. During the immediate recovery from exercise whatever its intensity, the magnitude of the ACTH response was increased in the trained subjects but with a reduced effect upon its target, the adrenal glands. This phenomenon has not been described in the literature. Two non-exclusive phenomena may be involved, i.e. a decreased adrenal sensitivity to ACTH stimulation, and/or a decreased hypothalamo-pituitary axis sensitivity to cortisol negative feedback.
Physiological Research, 2016
Acute exercise-induced changes in cortisol concentration (C) and training related adaptation within hypothalamic-pituitary-adrenal (HPA) axis has been widely examined, but their influence on muscle strength performance is at best uncertain. Twenty four young healthy men were randomly assigned to an endurance training group (ET, n=12) or to a non-exercising controls (CON, n=12). ET performed supervised endurance training on cycle ergometer for 20 weeks. Endurance training program improved exercise capacity (14 % increase in power output generated at peak oxygen uptake-VO2peak), muscle strength performance (increase in MVC-maximal voluntary contraction-by 9 % and in TTF 50 % MVC-time to fatigue at 50 % MVC-by 21 %) and led to a decrease in basal serum C concentration (P=0.006) and an increase in basal testosterone to cortisol (T/C) and free testosterone to cortisol (fT/C) ratios (P=0.01 and P=0.02, respectively). It was found that the decrease in C concentration (ΔC) was positively correlated to the increase in local muscular endurance (ΔTTF 50 % MVC). No significant hormonal changes were seen in CON group. It is concluded that greater decrease in cortisol concentration after the endurance training is accompanied by poorer improvement in skeletal muscle performance in previously untrained subjects.
Acute Endocrine Responses to Different Strength Exercise Order in Men
Journal of Human Kinetics, 2014
This study compared the effects of order of muscle groups' exercised (larger to smaller muscles vs. smaller to larger muscles) on the acute levels of total testosterone, free testosterone and cortisol during resistance training (RT) sessions. Healthy male participants (n=8; age: 28.8 ± 6.4 years; body mass: 87.0 ± 10.6 kg; body height: 181.0 ± 0.7 cm; BMI: 26.5 ± 4.1) were randomly separated into two experimental groups. The first group (LG-SM) performed an RT session (3 sets of 10 repetitions and a 2 min rest period) of the exercises in following order: bench press (BP), lat pulldown (LP), barbell shoulder press (BSP), triceps pushdown (TP) and barbell cut (BC). The second group (SM-LG) performed an RT session in following order: BC, TP, BSP, LA, BP. Blood was collected at the end of the last repetition of each session. Control samples of blood were taken after 30 min of rest. Significant differences were observed in the concentrations of total testosterone (p < 0.05), free testosterone (p < 0.0001) and cortisol (p < 0.0001) after both RT sessions in comparison to rest. However, when comparing LG-SM and SM-LG, no significant differences were found. The results suggest that, while RT sessions induce an acute change in the levels of testosterone and cortisol, this response is independent of the order of exercising muscle groups.
European Journal of Applied Physiology, 1998
The plasma noradrenaline (NA) and adrenaline (A) concentration responses of seven young male athletes [15 (SD 1) years] and seven adult male athletes [25 (SD 6) years] were investigated together with the serum testosterone (Tes) concentration responses in four dierent half-squatting exercises. The loads, number of repetitions, exercise intensity and recovery between the sets were manipulated such that dierent types of metabolic demand could be expected. However, the amount of work done was kept equal in each kind of exercise. After the most exhausting unit of exercise (E3; two sets of 30 repetitions with 50% of 1 repetition maximum and with 2-min recovery between the sets) the plasma NA concentration was signi®cantly lower in the younger than in the adult subjects [15.7 (SD 7.8) vs 32.7 (SD 13.2) nmol á l A1 , P < 0.05], while the A concentrations were similar. In the other three exercises no dierences in the plasma catecholamine concentration responses among the groups were observed. The postexercise Tes concentrations, however, were signi®cantly lower in the younger than in the adult subjects in every exercise unit. No correlations between the plasma catecholamine and serum Tes concentration responses were observed in any of the exercise units in either group. The results of the present study may suggest reduced sympathetic nervous activity in the younger subjects compared to the adults in response to exhausting resistance exercise. The results may also suggest that the catecholamines were less involved in eliciting an increase in Tes secretion in these resistance exercises.
Decreased pituitary sensitivity to glucocorticoids in endurance-trained men
European Journal of Endocrinology, 2001
OBJECTIVE: Muscular exercise induces hypothalamo-pituitary-adrenal (HPA) axis activation and when regularly repeated, as in endurance training, leads to HPA axis adaptation. To assess whether non-professional endurance-trained (ET) men with a substantial training load and no clinical or biological features of HPA axis overactivity can present subtle alterations of HPA axis sensitivity to glucocorticoid negative feedback, nine ET men were subjected to HPA axis testing using the dexamethasone-corticotrophin-releasing hormone (CRH) test. DESIGN: Nine endurance-trained men and eight healthy age-matched sedentary men were studied. Morning plasma cortisol and 24 h urinary free cortisol (UFC) were determined and a low dose dexamethasone suppression test (LDDST) was performed followed by CRH stimulation (dexamethasone-CRH test). RESULTS: After a day without physical exercise, at 0800 h, plasma ACTH and cortisol concentrations, and the 24 h UFC and UFC/urinary creatinine (UC) ratio were simi...
Exercise and the Hypothalamic-Pituitary-Adrenal Axis
The Endocrine System in Sports and Exercise
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Stress-the International Journal on The Biology of Stress, 2010
Exercise is a paradigm of a stress situation. The adaptive response to stressors comprises the activation of the hypothalamicpituitary-adrenal (HPA) axis and components of the autonomic sympathetic system. An aseptic inflammatory reaction is triggered by exercise, involving the stimulation of the so-called proinflammatory cytokines, such as tumor necrosis factor a (TNFa), interleukin-1 (IL-1), and IL-6. The anti-inflammatory cytokines IL-2, IL-8, and IL-10 increase moderately during resistance exercise. To investigate the effect of a short bout of resistance exercise on components of the stress and inflammatory responses during the exercise period, 17 healthy, young, untrained male volunteers were studied during 3 equal consecutive cycles of resistance exercises of 30 min total duration. Blood sampling was performed at baseline and at the end of each cycle. Lactate, cortisol, catecholamines (epinephrine, norepinephrine), IL-1a, IL-1b, IL-2, IL-6, IL-8, IL-10, epidermal growth factor (EGF), and monocyte chemotactic protein-1 (MCP-1) were measured at all time-points. Circulating levels of catecholamines and lactate increased significantly (P , 0.05) whereas cortisol did not. During the time course of the exercise, circulating levels of TNFa, IL-2, and EGF increased, whereas MCP-1 decreased significantly. IL-1a, IL-1b, IL-6, IL-8, and IL-10 levels did not change significantly. Statistically significant positive linear correlations were found between areas under the curve for increases in levels of IL-2 and TNFa, TNFa and cortisol, as well as epinephrine and norepinephrine. We conclude that acute resistance exercise results in catecholaminergic, but not HPA axis stimulation during exercise, in parallel with a mild inflammatory reaction. The absence of a major inflammatory reaction and of a cortisol increase during acute resistance exercise makes this a good candidate for the exercise of sedentary individuals.
Endocrine Response to High-Intensity Exercise: Dose-Dependent Effects of Dexamethasone 1
The Journal of Clinical Endocrinology & Metabolism, 2000
We recently reported that in 30 -50% of healthy men and women the release of ACTH and cortisol stimulated by exercise is not suppressed by prior administration of a 4-mg dose of dexamethasone (DEX). We now explore other potential differences between these subjects and those whose exercise response was suppressed by examining the effect of a smaller, 1-mg, dose of DEX on exercise-stimulated ACTH and cortisol. Men (n ϭ 15) and women (n ϭ 9) were studied during three high intensity exercise tests: one after taking placebo, one after taking 1 mg DEX, and one after taking 4 mg DEX. Before participation, subjects underwent a test for classification as either a high (HR; n ϭ 10) or low (LR; n ϭ 14) reactor and a maximal exercise test to assess maximal aerobic capacity. Distinct dose-related reductions in plasma concentrations of ACTH, cortisol, and dehydroepiandrosterone (DHEA) were noted for HR under the treatment conditions, whereas both doses of DEX blocked ACTH, cortisol, and DHEA release in LR. Furthermore, basal plasma cortisol, DHEA, and DHEA sulfate were significantly higher in HR compared to LR. Thus, there are inherent basal and stress-reactive differences in HR and LR, and these differences may be useful in constructing a model for the mechanisms and physiological regulation of hypothalamic-pituitaryadrenal axis activation. The question of whether these differences in reactivity of the ACTH-cortisol axis between the HR and LR groups have implications for individual short term function or long term health remains to be answered. (J Clin Endocrinol
Journal of Applied Physiology
Exercise-dependent growth hormone release is linked to markers of heightened central adrenergic outflow. J Appl Physiol 89: [629][630][631][632][633][634][635] 2000.-To test the hypothesis that heightened sympathetic outflow precedes and predicts the magnitude of the growth hormone (GH) response to acute exercise (Ex), we studied 10 men [age 26.1 Ϯ 1.7 (SE) yr] six times in randomly assigned order (control and 5 Ex intensities). During exercise, subjects exercised for 30 min (0900-0930) on each occasion at a single intensity: 25 and 75% of the difference between lactate threshold (LT) and rest (0.25LT, 0.75LT), at LT, and at 25 and 75% of the difference between LT and peak (1.25LT, 1.75LT). Mean values for peak plasma epinephrine (Epi), plasma norepinephrine (NE), and serum GH concentrations were determined [Epi: 328 Ϯ 93 (SE), 513 Ϯ 76, 584 Ϯ 109, 660 Ϯ 72, and 2,614 Ϯ 579 pmol/l; NE: 2.3 Ϯ 0.2, 3.9 Ϯ 0.4, 6.9 Ϯ 1.0, 10.7 Ϯ 1.6, and 23.9 Ϯ 3.9 nmol/l; GH: 3.6 Ϯ 1.5, 6.6 Ϯ 2.0, 7.0 Ϯ 2.0, 10.7 Ϯ 2.4, and 13.7 Ϯ 2.2 g/l for 0.25, 0.75, 1.0, 1.25, and 1.75LT, respectively]. In all instances, the time of peak plasma Epi and NE preceded peak GH release. Plasma concentrations of Epi and NE always peaked at 20 min after the onset of Ex, whereas times to peak for GH were 54 Ϯ 6 (SE), 44 Ϯ 5, 38 Ϯ 4, 38 Ϯ 4, and 37 Ϯ 2 min after the onset of Ex for 0.25-1.75LT, respectively. ANOVA revealed that intensity of exercise did not affect the foregoing time delay between peak NE or Epi and peak GH (range 17-24 min), with the exception of 0.25LT (P Ͻ 0.05). Within-subject linear regression analysis disclosed that, with increasing exercise intensity, change in (⌬) GH was proportionate to both ⌬NE (P ϭ 0.002) and ⌬Epi (P ϭ 0.014). Furthermore, within-subject multiple-regression analysis indicated that the significant GH increment associated with an antecedent rise in NE (P ϭ 0.02) could not be explained by changes in Epi alone (P ϭ 0.77). Our results suggest that exercise intensity and GH release in the human may be coupled mechanistically by central adrenergic activation. catecholamines; epinephrine; norepinephrine ALTHOUGH AN ACUTE BOUT OF exercise of appropriate intensity will evoke a large increase in serum GH con-Address for reprint requests and other correspondence: A. Weltman, Exercise Physiology Laboratory, Memorial Gymnasium, University of Virginia, Charlottesville, VA 22903 (E-mail: alw2v@ virginia.edu).
The Effects of Accute Submaximal Exercise on Some Stress Hormone Level
In the study, it is aimed to examine influence of Acute Submaximal exercise in the sportsmen and sedentary individuals who sport regularly on epinephrine and cortisol levels. Material and method: In the study 20 student subjects were used who were average 17-20 year old and 65-75 weight of 10 healthy male sportsmen from the Higher School of Physical Education and Sports and also 10 healthy boy students studying in other faculties. Subjects were divided into 2 groups: Sedentary group (S) and Exercise Group (E). Blood samples of both groups were taken; the first one before (OD) the specified exercise test and the second (ES) right after the completion of test. The third (E2S) blood sample was taken 2 hours after the exercise and the fourth (E24S) one 24 hours after the exercise Result: It was seen that Epinephrine OD values of the Group S significantly increased after exercise (P<0.05), while E2S value was indifferent to ES value and E24S value significantly decreased (P>0.05). It was seen found that Epinephrine OD values of the Group E significantly increased after exercise (P<0.05), while there was no significant change in ES and E2S levels, and E24S values significantly decreased (P<0.05) than the values after exercise (ES, E2S). It was found that cortisol OD values of Group S significantly increased after exercise (P<0.05). Although ES2 value was lower than the ES value, it was seen that they were statistically identical and levels of ES, E2S and E24S were significantly higher than OD level (p<0.05). E24S value significantly decreased than ES value (P<0.05). It was found that Cortisol OD values of Group E significantly increased (p<0.05) after the exercise and E2S and ES values were identical while E2S level was found significantly (P<0.05) higher than E24S level. E24S value was found significantly lower than ES value (P<0.05). E24S value was determined to be significantly higher than OD level. When epinephrine and cortisol levels were compared between two groups, any important difference was not seen. Discussion and conclusion: It was found that there is an important influence of submaximal exercised applied in this study in moderate intensity on Epinephrine and Cortisol levels