Article

Relationship Between Circulating Cortisol and Testosterone: Influence of Physical Exercise

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Abstract

Human research has shown the administration of cortisol into the circulation at rest will result in reduced blood testosterone levels. Many researchers have used these results to imply that physical exercise induced cortisol increases would perhaps result in subsequent reductions in circulating testosterone levels. Our purpose was to examine this concept and determine what, if any, relationship exists between circulating cortisol (C) and testosterone (T) in men (n = 45, 26.3 ± 3.8 yr) at rest and after exercise. Blood samples were collect at rest (10 hour post-prandial; denoted as 'Resting'; n = 45) and again on the same day at 1.0 hr into recovery from intensive exercise (denoted as 'Exercise Recovery'; n = 45). Approximately 48-96 hr after this initial (Trial # 1) blood collection protocol the subjects replicated the exact procedures again and provided a second Resting and Exercise Recovery set of blood samples (Trial # 2). Blood samples from Trial # 1and Trial # 2 were pooled (Resting, n = 90; Exercise Recovery, n = 90). The blood samples were analyzed by radioimmunoassay for C, total T (TT), and free T (fT). Pearson correlation coefficients for the Resting samples ([TT vs. C] r < +0.01; [fT vs. C] r = +0.06) were not significant (p > 0.05). For the Exercise Recovery samples ([TT vs. C] r = -0.53; [fT vs. C] r = +0.21) correlation coefficients were significant (p < 0.05). The findings indicate that exercise does allow the development of a significant negative relationship between C and TT. Interestingly, a significant positive relationship developed between C and fT following exercise; possibly due to an adrenal cortex contribution of fT or disassociation of fT from sex hormone binding globulin. The detected in vivo relationships between C and T, however, were associative and not causal in nature and were small to moderate at best in strength.

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... Interestingly, although there was a significant, positive relationship between pre-exercise cortisol and testosterone levels (and also between the change in cortisol and testosterone levels), we found that cortisol levels did not significantly change after physical exertion, which contradicts some previous results (Brownlee, Moore, & Hackney, 2005;Elias, 1981;Fry & Lohnes, 2010) but corroborates others (Kraemer et al., 2001). Furthermore, pre-exercise cortisol levels and changes in cortisol levels were negatively correlated, suggesting that higher pre-exercise cortisol levels may be linked to a blunted adrenal response to physical exercise. ...
... The positive relationship between pre-exercise cortisol and testosterone levels probably resulted from physiologically heightened levels and a stronger relationship between the two hormones during morning hours, as shown in previous studies (Gettler, Mcdade, & Kuzawa, 2011). This positive correlation contrasts with the dual-hormone hypothesis (Mehta & Josephs, 2010), which indicates that higher levels of cortisol may blunt a testosterone rise during physical exercise; therefore, a negative relationship between cortisol and testosterone should be expected (Brownlee et al., 2005;Cumming, Quigley, & Yen, 1983). However, previous research showed that cortisol and testosterone were inversely correlated during exercise only when cortisol was highly elevated (~160% above resting levels), suggesting that a critical level of cortisol must be reached in order to substantially influence circulating testosterone levels (Brownlee et al., 2005). ...
... This positive correlation contrasts with the dual-hormone hypothesis (Mehta & Josephs, 2010), which indicates that higher levels of cortisol may blunt a testosterone rise during physical exercise; therefore, a negative relationship between cortisol and testosterone should be expected (Brownlee et al., 2005;Cumming, Quigley, & Yen, 1983). However, previous research showed that cortisol and testosterone were inversely correlated during exercise only when cortisol was highly elevated (~160% above resting levels), suggesting that a critical level of cortisol must be reached in order to substantially influence circulating testosterone levels (Brownlee et al., 2005). In our study, there was no significant increase in cortisol levels. ...
Article
Human male height is one of the most conspicuous sexually dimorphic, phenotypic characteristics that affect how men are perceived both by men and women, impacting mate selection and intra-sexual competition. Testosterone is a key hormone linked to morphological masculinity and advantage in intra-sexual competition. To date, there have been limited studies linking height with testosterone levels. Here, we examined the change in circulating testosterone levels after physical exercise in 97 healthy and physically active men. Our results show that there was a significant relationship between male stature and the change in testosterone levels, whereas there was no such link between body height and circulating testosterone levels. Therefore, our findings provide evidence that height may indicate male’s adaptive capabilities to physiologically mobilize their bodies when it is needed and/or beneficial.
... CORT's metabolic roles are critical for everyday energy expenditure (EE) including responding to levels of physical activity. In U.S.and European-based lab settings, acute CORT increases substantially only in response to intensive physical activity (Brownlee, Moore, & Hackney, 2005). However, CORT's metabolic roles may be more sensitive and responsive during every day physical activity in highly active populations facing energetic constraints, such as in foraging societies (Pontzer et al., 2012). ...
... Yet, most of our knowledge on acute CORT responses to such physical demands comes from a narrow range of study designs and populations in the United States and Europe. For example, exercise physiology research specifically looking at athletes in controlled laboratory settings shows that CORT tends to go up acutely during rigorous workouts (Brownlee et al., 2005). Similarly, many studies have documented that athletes' CORT rises during sporting events, regardless of fasting status (Casto, Elliott, & Edwards, 2014;Maughan et al., 2008). ...
... Contrary to our prediction, we found that males who had greater % MVPA experienced more substantial short-term decreases in CORT during the first 30 min of daily activity (Figure 2). This pattern contrasts with research in clinical/laboratory settings as well as some field settings showing that CORT often rises in response to demanding physical activity (Brownlee et al., 2005;Casto et al., 2014;Trumble et al., 2014). While our findings potentially indicate that intensive physical activity had a dampening effect on short-term CORT production in this setting, there are a number of alternative explanations that could help to account for these observations. ...
Article
Objectives The pooling of energetic resources and food sharing have been widely documented among hunter‐gatherer societies. Much less is known about how the energetic costs of daily activities are distributed across individuals in such groups, including between women and men. Moreover, the metabolic physiological correlates of those activities and costs are relatively understudied. Materials and methods Here, we tracked physical activity, energy expenditure (EE), and cortisol production among Congo Basin BaYaka foragers engaged in a variety of daily subsistence activities (n = 37). Given its role in energy mobilization, we measured overall daily cortisol production and short‐term cortisol reactivity through saliva sampling; we measured physical activity levels and total EE via the wGT3X‐bt actigraph and heart rate monitor. Results We found that there were no sex differences in likelihood of working in common activity locations (forest, garden, house). Across the day, women spent greater percentage time in moderate‐to‐vigorous physical activity (%MVPA) and had lower total EE than men. Females with higher EE (kCal/hr) produced greater cortisol throughout the day. Though not statistically significant, we also found that individuals with greater %MVPA had larger decreases in cortisol reactivity. Discussion BaYaka women sustained higher levels of physical activity but incurred lower energetic costs than men, even after factoring in sex differences in body composition. Our findings suggest that the distribution of physical activity demands and costs are relevant to discussions regarding how labor is divided and community energy budgets take shape in such settings.
... Testosterone is associated with multiple physiological functions in the human body. In males, TES is produced and secreted mainly by the Leydig cells of the testes (Brownlee et al., 2005). In physically active individuals, TES is especially important for the growth and maintenance of skeletal muscles, bones, and red blood cells (Zitzmann & Nieschlag, 2001). ...
... Similarly to COR, TES increases linearly in response to exercise stress once a specific intensity threshold is reached, and its levels generally peak at the end of exercise (Wilkerson et al., 1980). Testosterone and COR levels can increase significantly even during low intensity exercise that is sufficiently prolonged (Brownlee et al., 2005;Väänänen et al., 2002). COR is a catabolic hormone that is secreted by the adrenal cortex in response to physiological stress. ...
... Cumming et al. (1983) reported that an increase in the pharmacological doses of COR decreased TES production in humans. Nindl et al. (2001), Daly et al. (2005) and Brownlee et al. (2005) confirmed the presence of a relationship between COR and TES during sample recovery, which could suggest that a critical concentration of COR has to be achieved in order to substantially influence circulating TES levels. The present study did not reveal any interactions between TES and COR. ...
Article
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The aim of the study was to determine the effect of repeated hot thermal stress and cold water immersion on the endocrine system of young adult men with moderate and high levels of physical activity (PA). The research was conducted on 30 men aged 19–26 years (mean: 22.67 ± 2.02) who attended four sauna sessions of 12 min each (temperature: 90−91°C; relative humidity: 14–16 %). Each sauna session was followed by a 6-min cool-down break during which the participants were immersed in cold water (10−11°C) for 1 min. Testosterone (TES), cortisol (COR), dehydroepiandrosterone sulfate (DHEA-S), and prolactin (PRL) levels were measured before and after the sauna bath. The participants’ PA levels were evaluated using the International Physical Activity Questionnaire. Serum COR levels decreased significantly ( p < .001) from 13.61 to 9.67 µg/ml during 72 min of sauna treatment. No significant changes ( p >.05) were noted in the concentrations of the remaining hormones: TES increased from 4.04 to 4.24 ng/ml, DHEA-S decreased from 357.5 to 356.82 µg/ml, and PRL decreased from 14.50 to 13.71 ng/ml. After sauna, a greater decrease in COR concentrations was observed in males with higher baseline COR levels, whereas only a minor decrease was noted in participants with very low baseline COR values ( r =−0.673, p <.001). Repeated use of Finnish sauna induces a significant decrease in COR concentrations, but does not cause significant changes in TES, DHEA-S, or PRL levels. Testosterone concentrations were higher in men characterized by higher levels of PA, both before and after the sauna bath.
... Testosterone is associated with multiple physiological functions in the human body. In males, TES is produced and secreted mainly by the Leydig cells of the testes (Brownlee et al., 2005). In physically active individuals, TES is especially important for the growth and maintenance of skeletal muscles, bones, and red blood cells (Zitzmann & Nieschlag, 2001). ...
... Similarly to COR, TES increases linearly in response to exercise stress once a specific intensity threshold is reached, and its levels generally peak at the end of exercise (Wilkerson et al., 1980). Testosterone and COR levels can increase significantly even during low intensity exercise that is sufficiently prolonged (Brownlee et al., 2005;Väänänen et al., 2002). COR is a catabolic hormone that is secreted by the adrenal cortex in response to physiological stress. ...
... Cumming et al. (1983) reported that an increase in the pharmacological doses of COR decreased TES production in humans. Nindl et al. (2001), Daly et al. (2005) and Brownlee et al. (2005) confirmed the presence of a relationship between COR and TES during sample recovery, which could suggest that a critical concentration of COR has to be achieved in order to substantially influence circulating TES levels. The present study did not reveal any interactions between TES and COR. ...
Article
The aim of the study was to determine the effect of repeated hot thermal stress and cold water immersion on the endocrine system of young adult men with moderate and high levels of physical activity (PA). The research was conducted on 30 men aged 19–26 years (mean: 22.67 ± 2.02) who attended four sauna sessions of 12 min each (temperature: 90−91°C; relative humidity: 14–16 %). Each sauna session was followed by a 6-min cool-down break during which the participants were immersed in cold water (10−11°C) for 1 min. Testosterone (TES), cortisol (COR), dehydroepiandrosterone sulfate (DHEA-S), and prolactin (PRL) levels were measured before and after the sauna bath. The participants’ PA levels were evaluated using the International Physical Activity Questionnaire. Serum COR levels decreased significantly (p < .001) from 13.61 to 9.67 µg/ml during 72 min of sauna treatment. No significant changes (p >.05) were noted in the concentrations of the remaining hormones: TES increased from 4.04 to 4.24 ng/ml, DHEA-S decreased from 357.5 to 356.82 µg/ml, and PRL decreased from 14.50 to 13.71 ng/ml. After sauna, a greater decrease in COR concentrations was observed in males with higher baseline COR levels, whereas only a minor decrease was noted in participants with very low baseline COR values (r =−0.673, p <.001). Repeated use of Finnish sauna induces a significant decrease in COR concentrations, but does not cause significant changes in TES, DHEA-S, or PRL levels. Testosterone concentrations were higher in men characterized by higher levels of PA, both before and after the sauna bath.
... Cortisol is a hormone that mobilises fuel stores such as carbohydrate and fat and can also suppress the immune system (Armstrong & Vanheest, 2002;Brownlee, Moore, & Hackney, 2005). Greenham, Buckley, Garrett, Eston, & Norton (2018) conducted a systematic review including 42 studies. ...
... Testosterone is a hormone that aids in the growth of skeletal muscle (Brownlee et al., 2005). There was no significant change in blood testosterone in response to intensified training (Garrett et al., 2018). ...
Thesis
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Background: The popularity of endurance running events has rapidly increased in recent years with more recreational runners entering the field. How recreational runners train is not well known. Understanding this and the relationship between training and performance in this group of runners is important for prescribing appropriate training to maximise performance and decrease the risk of injury. This forms the underlying theme throughout this thesis. Aim: The broad aims of this thesis were to better understand the ad libitum training habits of well-trained competitive recreational runners and to determine the relationships between performance, training load, and submaximal heart rate (HR) in this cohort. Methods: Five inter-related studies were performed to: 1) determine relationships between 56-km race performance and pacing (n = 7,327) in competitive recreational runners; 2) determine relationships between 56-km race performance, pacing, and training load in competitive recreational runners (n = 69); 3) determine the accuracy of GPS sport watches in measuring distance (n = 255); 4) develop a feasible and reliable submaximal running test, and 5) determine relationships between performance on a submaximal running test, training load, and submaximal HR in well-trained competitive recreational runners (n = 29). Main findings: A group of well-trained competitive recreational runners performed 44  22 km/week (median  IQR) in a six-month time frame while training ad libitum. This group had a wide range of inter-individual differences in training load performed even when considering participants who had the same relative marathon performance. The same group of well-trained competitive recreational runners maintained most of their training over a six-month period in a range of 0.81 – 1.14 for the acute: chronic workload ratio (ACWR). When the ACWR values reached > 1.50, it was mainly due to participation in endurance running races (> 21-km). When looking at relative weekly changes in training load, the maximum increase was 30% with only two participants having maximum increases of < 10%. The increases in load were predominantly short term (one to two weeks). Submaximal HR had a negative linear relationship with performance in 21% of the study participants. In those participants, poor performances were associated with a higher submaximal HR. Training load was only related to changes in performance in one participant. Conclusion: This thesis confirms that no single variable can provide the necessary information on how to adjust training load to maximise performance. Athletes, coaches, and sports scientists need to have a holistic view of stress exposure and how this affects the body. Although we can only speculate, when the participants had a poor performance it may have been due to factors such as lack of motivation, fatigue, mental stress, dehydration, and/or sleep deprivation. It is important for runners, coaches, and sports scientists to approach the training load – recovery balance as being unique for each athlete. Even in a homogenous group of well-trained competitive recreational runners, their ad libitum training load is widely varied and was not associated with performance or ability level. The balance should be adjusted over time based on the athlete’s symptoms.
... We also explored the possible effect of cortisol activity on the relationship between the 2D:4D and a testosterone response to a physical exertion. Both hormones, testosterone and cortisol, are expected to increase in response to a physical activity [57][58][59] (but see also 60 ), and cortisol has been shown to influence a testosterone www.nature.com/scientificreports www.nature.com/scientificreports/ ...
... secretion and activity [39][40][41] , thus, cortisol may impact the relationship between the 2D:4D and the adult testosterone level or testosterone response to a physical exertion. We found a positive relationship between a testosterone and cortisol change in response to an acute exercise, what was also shown in previous studies [57][58][59] , but we found no link between cortisol, testosterone, a testosterone change, and the 2D:4D. It may be that cortisol increases only in certain situations, perceived as stressful 61 , while our study, although physically demanding, did not elicit a psychologically stressful response. ...
Article
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The digit ratio (2D:4D) is said to be a potential marker of exposure to prenatal sex steroids. Some studies suggest that the 2D:4D is also linked with the testosterone response to challenging situations due to organizational effect of prenatal hormonal milieu on adult endocrine functioning. However, up to date, there were only four studies (conducted on small samples) that examined the 2D:4D and the testosterone response to a challenging situation (i.e. physical exertion or aggressive context). Here, we examined the relationship between the 2D:4D and the testosterone change under an acute exercise among 97 men. We found that the digit ratios (the right 2D:4D, the left 2D:4D, and the right minus left 2D:4D) were neither predictors of pre-exercise testosterone, nor the change in testosterone level after a cycling task. Our results add a contradictory to previous studies evidence in a discussion on the links of the 2D:4D and the testosterone change.
... Testosterone and cortisol exert opposing effects, compete for glucocorticoid-binding sites (Hackney & Walz, 2013), and vary inversely during exercise (Brownlee et al., 2005). Moderate to high-intensity (80% of 1RM, 120 s rest period), high-volume resistance training acutely induces high levels of testosterone in young men (Crewther et al., 2008;Juan, 2019), but also high cortisol in men with metabolic disorders (Gar et al., 2020;Wong & Harber, 2006). ...
... People with metabolic disorders have been shown to have blunted exercise-induced growth hormone response (Wong et al., 2006) and exaggerated cortisol response (Gar et al., 2020) to exercise. Testosterone and cortisol exert opposing effects, compete for glucocorticoid-binding sites (Hackney & Walz, 2013), and vary inversely during exercise (Brownlee et al., 2005). There is evidence that cortisol may be a more important determinant of anabolic status than testosterone (Ratamess et al., 2005). ...
... Cortisol is regulated by the hypothalamus-pituitary-adrenal axis [7,8]. Studies have suggested that an increase in cortisol concentration may have a negative effect on TT concentration [9][10][11], however, initial studies have shown a positive correlation between FT and C levels after physical exercise [11]. ...
... Cortisol is regulated by the hypothalamus-pituitary-adrenal axis [7,8]. Studies have suggested that an increase in cortisol concentration may have a negative effect on TT concentration [9][10][11], however, initial studies have shown a positive correlation between FT and C levels after physical exercise [11]. ...
Article
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Background: Hormones like testosterone play a crucial role in performance enhancement and muscle growth. Therefore, various attempts to increase testosterone release and testosterone concentration have been made, especially in the context of resistance training. Among practitioners, sexual activity (coitus and masturbation) a few hours before training is often discussed to result in increases of testosterone concentration and thus promote muscle growth. However, there is no evidence to support this assumption and the kinetics of the testosterone and cortisol response after sexual activity have not been adequately investigated. Therefore, the aim of this pilot-study was to examine the kinetics of hormone concentrations of total testosterone, free testosterone and cortisol and their ratios after masturbation. In a three-arm single blinded cross-over study, the effects of masturbation with visual stimulus were compared to a visual stimulus without masturbation and the natural kinetics in healthy young men. Results: The results showed a significant between-condition difference in free testosterone concentrations. Masturbation (p < 0.01) and a visual stimulus (p < 0.05) may seem to counteract the circadian drop of free testosterone concentrations over the day. However, no statistical change was observed in the ratios between total testosterone, free testosterone and cortisol. Conclusions: It can be assumed that masturbation may have a potential effect on free testosterone concentrations but not on hormonal ratios. However, additional studies with larger sample sizes are needed to validate these findings.
... Another potential mechanism through which herbs may increase testosterone concentrations in males is by ameliorating cortisol production. Since cortisol, the body's major stress hormone, is inversely correlated with testosterone concentrations (85), reducing its production may elevate testosterone concentrations. In several human trials, ashwagandha supplementation was associated with reduced cortisol concentrations (75,76), potentially contributing to the testosterone-enhancing effects identified in 3 out of 4 studies herein. ...
Article
Testosterone concentrations in males tend to decline with advancing age. Low testosterone, also known as androgen deficiency (AD), is associated with an increased risk of morbidity and mortality. Currently, the primary treatment for AD is testosterone replacement therapy (TRT), which may exacerbate pre-existing medical conditions. Therefore, the use of alternative options, such as herbs, spices, plants, or their extracts, has been explored as a potential treatment option for AD. The aim of this systematic review was to summarize and critically evaluate randomized controlled trials published on the efficacy of single herbal ingredients on testosterone concentrations, in addition to its fractions or binding proteins, in men (≥18 y). From the 4 databases searched, there were 13 herbs identified in 32 studies, published between 2001 and 2019. The main findings of this review indicate that 2 herbal extracts, fenugreek seed extracts and ashwagandha root and root/leaf extracts, have positive effects on testosterone concentrations in men. Also, some evidence exists for another herb and herbal extract, Asian red ginseng and forskohlii root extract. Overall, 9 out of 32 studies demonstrated statistically significant increases in testosterone concentrations. Moreover, 6 studies out of 32 were judged as having a low risk of bias. Current evidence is largely based on young, nonclinical populations, with 16 out of 32 studies using men <40 y of age. Conclusions are moderated by the paucity of research for many herbs, the variation in dosages and extracts used, small sample sizes, and the heterogeneity of study characteristics. Also, further research is required before definitive conclusions on efficacy and safety can be made. This systematic review was registered at PROSPERO as CRD42020173623. Adv Nutr 2020;00:1-22.
... Previous results demonstrate pharmacological levels of cortisol have a highly significant negative effect on circulating testosterone concentrations [27,28]. However, the findings of another study [29] indicated a significant negative relationship between cortisol and total testosterone in exercise and a significant positive relationship between cortisol and free testosterone following exercise; possibly due to an adrenal cortex contribution of free testosterone or disassociation of free testosterone from sex hormone binding globulin. They suggested that the in vivo relationships between cortisol and testosterone were associative and not causal in nature. ...
Article
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Introduction: Women have high anxiety and depression incidence compared to men. In the present study, gender-related differences in correlations among BMI, salivary testosterone and cortisol and depression and alexithymia scores in university students. Methods: A total of 88 Nigerian university students were involved in the study. Participants were 20 men and 68 women who were 17-25 years of age. Salivary assay of cortisol and testosterone were done using Enzyme-linked Immunosorbent Assay Kits. The Self-Reporting Questionnaire (SRQ) 20 adapted from WHO was used to screen for depression. Toronto Alexithymia Scale was used to assess the points associated with alexithymia. Results: In the present study, there was a significant negative correlation between testosterone and depression in only men, but not in the total sample and women. There were significant positive correlations between depression and alexithymia scores in the total sample and women, but not in men. Discussion: The gender difference in the relation of salivary testosterone with depression showed again that gender is a very important factor in behavioral studies including depression. It can be stated that testosterone can be an important hormonal factor to prevent or decrease depression or depressive thoughts in men but not in women. The positive correlations between depression and alexithymia scores suggest that high depression in female university students is related to social and environmental factors, but not low testosterone. Conclusion: These results suggest that high depression in female healthy university students is may be due to social, cultural, and ecological factors, but not hormonal (cortisol and testosterone) factors.
... Previous results demonstrate pharmacological levels of cortisol have a highly significant negative effect on circulating testosterone concentrations [27,28]. However, the findings of another study [29] indicated a significant negative relationship between cortisol and total testosterone in exercise and a significant positive relationship between cortisol and free testosterone following exercise; possibly due to an adrenal cortex contribution of free testosterone or disassociation of free testosterone from sex hormone binding globulin. They suggested that the in vivo relationships between cortisol and testosterone were associative and not causal in nature. ...
... Analysis of blood corticosterone levels indicated that mice subjected to the exercise protocol had higher corticosterone levels than animals without exercise. It is known that exercise stimulates the HPA axis, which results in the release of GCs [65]. By comparing di↵erent studies, some authors speculate a positive correlation between the amount of exercise and blood corticosterone levels [66,67]. ...
Article
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Glucocorticoids (GCs) are critical regulators of energy balance. Their deregulation is associated with the development of obesity and metabolic syndrome. However, it is not understood if obesity alters the tissue glucocorticoid receptor (GR) response, and moreover whether a moderate aerobic exercise prevents the alteration in GR response induced by obesity. Methods: To evaluate the GR response in obese mice, we fed C57BL6J mice with a high-fat diet (HFD) for 12 weeks. Before mice were sacrificed, we injected them with dexamethasone. To assess the exercise role in GR response, we fed mice an HFD and subjected them to moderate aerobic exercise three times a week. Results: We found that mice fed a high-fat diet for 12 weeks developed hepatic GC hypersensitivity without changes in the gastrocnemius or epididymal fat GR response. Therefore, moderate aerobic exercise improved glucose tolerance, increased the corticosterone plasma levels, and prevented hepatic GR hypersensitivity with an increase in epididymal fat GR response. Conclusion: Collectively, our results suggest that mice with HFD-induced obesity develop hepatic GR sensitivity, which could enhance the metabolic effects of HFD in the liver. Moreover, exercise was found to be a feasible non-pharmacological strategy to prevent the deregulation of GR response in obesity.
... One might anticipate that the high-intensity nature of the present combined training could have caused transient changes in absolute hormone concentrations; however, acute responses to training are unlikely to be observed in basal measurements. While the activity of the pituitary-adrenocortical system may be an indicator of training stress or training intensity (Brownlee et al., 2005;Tremblay et al., 2005) and while TES and COR (and their ratio) have been used to indicate overreaching/overtraining and of an anabolic/catabolic state (Häkkinen et al., 1985;Adlercreutz et al., 1986), we should recognize that the observed increase in COR may actually be a favorable adaptation (Viru and Viru, 2004) and that negative training stress may not be fully reflected in basal concentrations of the measured hormones (Kuoppasalmi et al., 1980;Consitt et al., 2002). ...
Article
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Purpose: To examine the potential sex differences in adaptations to combined endurance and strength training in recreationally endurance trained (eumenorrheic) women (n = 9) and men (n = 10). Methods: Isometric (ISOMmax) and dynamic bilateral leg press (1RM), countermovement jump (CMJ), running performance (3,000 m time trial), lean mass and body fat % (LEAN and FAT% determined by dual X-ray absorptiometry) as well as serum testosterone and cortisol (TES and COR, respectively, measured using hormone-specific immunoassay kits) were examined before a control period and pre, mid, and post a supervised 10-week combined high-intensity interval endurance training (4 × 4 min intervals and 3 × 3 × 100 m repeated sprints) and mixed maximal and explosive strength training. No more than 2 weeks separated training and testing for either women or men and all women were tested in the early follicular phase of the menstrual cycle to minimize the possible influence of menstrual cycle phase on performance measures. Results: Absolute and relative changes in 1RM, CMJ, 3,000 m, LEAN, and FAT% were similar between groups. The only statistically significant differences observed between groups were observed at post and included a larger Δ% increase in ISOMmax force in men and a relatively greater Δ% decrease in serum TES in women. Conclusion: Women and men can achieve similar relative adaptations in dynamic maximal strength and CMJ as well as endurance performance gains and body composition over the same high-intensity 10-week combined program, although relative adaptations in TES may differ.
... The methods used to induce dehydration can also influence these hormonal responses. Additional stressor commonly imposed in the dehydration literature include exercise, heat exposure, and caloric restriction, which can all independently influence hormonal levels [58][59][60]. With dehydration techniques that increase body temperature, the effects of hypohydration alone cannot be determined without sufficient time for cooling [6]. ...
Article
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Evidence synthesizing the effects of acute body water losses on various markers of glycemic regulation, appetite, metabolism, and stress is lacking. Thus, the purpose of this review was to summarize the response of various hormonal changes involved in these physiologic functions to dehydration. A comprehensive literature search for peer-reviewed research in the databases PubMed, Scopus, CINAHL, and SportDiscus was conducted. Studies were included if they contained samples of adults (>18 years) and experimentally induced dehydration as measured by acute body mass loss. Twenty-one articles were eligible for inclusion. Findings suggested cortisol is significantly elevated with hypohydration (standard mean difference [SMD] = 1.12, 95% CI [0.583, 1.67], p < 0.0001). Testosterone was significantly lower in studies where hypohydration was accompanied by caloric restriction (SMD= −1.04, 95% CI [−1.93, −0.14], p = 0.02), however, there were no changes in testosterone in studies examining hypohydration alone (SMD = −0.17, 95% CI [−0.51 0.16], p = 0.30). Insulin and ghrelin were unaffected by acute total body water losses. Acute hypohydration increases markers of catabolism but has a negligible effect on markers of glycemic regulation, appetite, anabolism and stress. Given the brevity of existing research, further research is needed to determine the impact of hydration on glucagon, leptin, peptide YY and the subsequent outcomes relevant to both health and performance.
... It has been suggested that the concurrent training-related interference effect is age-dependent and present in adolescents (13-18 yrs.) but not in children (6-12 yrs.) [2]. In adults, acute hormonal response to concurrent training in the same training session can be metabolically demanding, increasing cortisol concentration and potentially suppressing testosterone post-loading [87]. Moreover, the order of exercise also seems to play a role in exercise-induced hormonal responses. ...
Article
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Background No previous systematic review has quantitatively compared the effects of resistance training, endurance training, or concurrent training on hormonal adaptations in children and adolescents. Objective was to examine the effects of exercise training and training type on hormonal adaptations in children and adolescents. Methods A systematic literature search was conducted in the following databases: PubMed, Web of Science, and EBSCO. Eligibility criteria were: population: healthy youth population sample (mean age < 18 years); intervention: resistance training, endurance training, or concurrent training (> 4 weeks duration); comparison: control group; outcome: pre- and post-levels of hormones and cytokines; and study design: randomized and non-randomized controlled trials. We used a random-effect model for the meta-analysis. The raw mean difference in hormones from baseline to post-intervention was presented alongside 95% confidence intervals (CI). Further, the certainty of evidence quality and the risk of bias were assessed. Results A total of 3689 records were identified, of which 14 studies were eligible for inclusion. Most studies examined adolescents with fewer studies on children (age < 12 years, N = 5 studies) and females (N = 2 studies). Nine exercise training programs used endurance training, five studies used resistance training, and no eligible study used concurrent training. The meta-analysis showed no significant effect of exercise training on testosterone (MD = 0.84 nmol/L), cortisol (MD = − 17.4 nmol/L), or SHBG (MD = − 5.58 nmol/L). Subgroup analysis showed that resistance training significantly increased testosterone levels after training (MD = 3.42 nmol/L) which was not observed after endurance training (MD = − 0.01 nmol/L). No other outcome differed between training types. Exercise training resulted in small and non-significant changes in GH (MD = 0.48 ng/mL, p = 0.06) and IGF-I (MD = − 22.90 ng/mL, p = 0.07). GH response to endurance training may be age-dependent and evident in adolescents (MD = 0.59 ng/mL, p = 0.04) but not when children and adolescents are pooled (MD = 0.48 ng/mL, p = 0.06). Limited evidence exists to conclude on IL-6 and TNF-α effects of exercise training. Assessments of GRADE domains (risk of bias, consistency, directness, or precision of the findings) revealed serious weaknesses with most of the included outcomes (hormones and cytokines). Conclusions This systematic review suggests that exercise training has small effects on hormonal concentrations in children and adolescents. Changes in testosterone concentrations with training are evident after resistance training but not endurance training. GH's response to training may be affected by maturation and evident in adolescents but not children. Further high-quality, robust training studies on the effect of resistance training, endurance training, and concurrent training are warranted to compare their training-specific effects. Registration: PROSPERO: CRD42021241130.
... Cortisol (C) is the main glucocorticoid of the organism, its secretion is produced in the adrenal glands and it is controlled through a negative feedback mechanism by the hypothalamuspituitary-adrenal axis [3]. It is a hormone modulated by circadian rhythms, but factors such as mental stress, dehydration or food can alter its production [4]. ...
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The aim of this study was to determine the possible changes in plasma of several hormones such as Luteinizing Hormone, Testosterone, Cortisol and Insulin in endurance runners during the sports season. Twenty-one high-level male endurance runners (22 ± 3.2 years, 1.77 ± 0.05 m) participated in the study. Basal plasma hormones were measured at four moments during the season (initial, 3, 6 and 9 months), and were analyzed using ELISA (enzyme-linked immunosorbent assay). Testosterone and Luteinizing Hormone (LH) suffered very significant decreases (p < 0.01) at 3 months compared with the beginning and an increase (p < 0.05) at 6 and 9 months compared with 3 months. Insulin level was significantly lower (p < 0.05) at 3, 6 and 9 months compared with the initial test. Insulin and cortisol were associated inversely (r = 0.363; β = −0.577; p = 0.017) and positively (r = 0.202; β = 0.310; p = 0.043), respectively, with the amount of km per week performed by the runners. There was a significant association between km covered at a higher intensity than the anaerobic threshold and I (r = 0.580; β = −0.442; p = 0.000). Our findings indicate that testosterone, LH and insulin were more sensitive to changes in training volume and intensity than cortisol in high-level endurance runners. Basal testosterone and LH concentrations decrease in athletes who perform a high volume of aerobic km in situations of low energy availability.
... Testosterone response may have been conditioned by the cortisol levels observed after the CF workouts. High cortisol levels in response to anaerobic exercise possibly caused a potential for inhibition of testosterone production via steroid inhibition, and thus, cortisol induced a direct suppressive effect on testosterone steroidogenesis [61]. ...
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Background Acute beetroot juice (BJ) intake has shown to enhance aerobic and anaerobic performance. However, no studies have evaluated the effects of BJ intake on CrossFit (CF) performance by linking hormonal, metabolic, and mechanical responses. The purpose of this study was to determine the causal physiological association between hormonal, metabolic and mechanical responses, and CF workouts performance after acute BJ intake. Methods Twelve well-trained male practitioners undertook a CF workout after drinking 140 mL of BJ (~ 12.8 mmol NO 3 ⁻ ) or placebo. The two experimental conditions (BJ or placebo) were administered using a randomized, double-blind, crossover design. The CF workout consisted of repeating the same exercise routine twice: Wall ball (WB) shots plus full back squat (FBS) with 3-min rest (1st routine) or without rest (2nd routine) between the two exercises. A 3-min rest was established between the two exercise routines. Results An interaction effect was observed in the number of repetitions performed ( p = 0.04). The Bonferroni test determined a higher number of repetitions after BJ than placebo intake when a 3-min rest between WB and FBS (1st routine) was established ( p = 0.007). An interaction effect was detected in cortisol response ( p = 0.04). Cortisol showed a higher increase after BJ compared to placebo intake (76% vs. 36%, respectively). No interaction effect was observed in the testosterone and testosterone/cortisol ratio ( p > 0.05). A significant interaction effect was found in oxygen saturation ( p = 0.01). A greater oxygen saturation drop was observed in BJ compared to placebo ( p < 0.05). An interaction effect was verified in muscular fatigue ( p = 0.03) with a higher muscular fatigue being observed with BJ than placebo ( p = 0.02). Conclusions BJ intake improved anaerobic performance only after the recovery time between exercises. This increase in performance in the first routine probably generated greater hypoxia in the muscle mass involved, possibly conditioning post-exercise performance. This was observed with a fall in oxygen saturation and in muscle fatigue measured at the end of the CF workout. The greatest perceived changes in cortisol levels after BJ intake could be attributed to the nitrate-nitrite-nitric oxide pathway.
... Es evidente que la no intervención durante las 6 semanas de competición refleja un menor daño muscular con niveles más bajos de carga fisiológica. Por otra parte, la TL se incrementa linealmente y dicho fenómeno sería en respuesta inducida al ejercicio sobre una intensidad-umbral determinada (Brownlee, Moore, Hackney, 2005). En el estudio de Kraemer y col., (2004), los cuales compararon niveles hormonales en jugadores titulares y suplentes de la Liga Universitaria NCAA, el grupo "suplentes" incrementó significativamente la TL a las siete semanas del período competitivo, aunque el índice T/C se mantuvo estable para ambos grupos. ...
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The aim of this study is to analyze changes of stress-related biochemical markers in Argentine professional soccer players (n = 22) at 3 timepoints during the soccer season: beginning of preseason (E1), beginning of season (E2), and after 6 weeks of competitive season (E3). The sample of players was divided in two groups of 11: starters players during the first seven matches of the season, and substitute players. Concentrations of creatine kinase (CK), lactic-acid dehydrogenase (LDH), testosterone (TL) and cortisol (C) were assayed in serum samples, and testosterone-cortisol ratio (T/C) was also calculated. We observed no significant differences between both groups during preseason (E1-E2), but a higher in-season level of TL and T/C (E3>E2; p< 0.05) was observed in non-starter players. Besides, a decrement of LDH values were determined in this group during the season (E3<E2; p< 0.05). In conclusion, this study shows that soccer players face no significant difference between both groups during preseason, but significant difference in biomarkers of physiologic strain and hormonal stress-related parameters during the season suggest a positive balance in non-starters players. Keywords: professional players; biomarkers; physiologic and hormonal stress; preseason; season.
... higher gains in the EG, with larger effect size values. Once again one could highlight the importance of specific adaptation related to ballistic movements during the ST.33,43,44 All results presented and discussed help to realize that several factors can influence the improvement of swimming performance for swimmers of this level. ...
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Background/objective This study aimed to examine the effects of eight weeks of dry-land strength combined with swimming training on the development of upper and lower body strength, jumping ability, and swimming performance in competitive sprinter swimmers. Methods Twenty (14 men and 6 women) university swimmers of national-level (age: 20.55 ± 1.76 years, body mass: 68.86 ± 7.69 kg, height: 1.77 ± 0.06 m, 100 m front crawl: 71.08 ± 6.71s, 50 m front crawl: 31.70 ± 2.45s) were randomly divided into two groups: experimental group (EG: 11) and control group (CG: 9). In addition to the usual in-water training (3–4 sessions per week of ∼80 min), the EG performed 8 weeks (one session per week) of strength-training (ST). The ST included bench press, full squat, countermovement jumping, countermovement jumping with free-arm movement, and the medical ball throwing. Stroke length, stroke frequency, stroke index, and swimming velocity were recorded during 50 and 100 m front crawl time-trials. Strength and swimming performance were evaluated before and after 8 weeks of training. Results The results showed a significant improvement in sprint performance (50 m: p < 0.01, d = 0.47; 100 m: p < 0.05, d = 0.42), stroke frequency (50 m: p < 0.01, d = 0.90) and stroke index (100 m: p < 0.01, d = 0.29) in the EG. Despite both groups’ increased strength performance, increases in bench press were higher in the EG (p < 0.001, d = 0.75) than CG (p = 0.05, d = 0.34). Conclusions Complementing in-water training with strength training seems to be relevant to improve upper body strength and to optimize 50 m and 100 m swimming performance, adapting technical patterns used during all-out swimming.
... Previous results demonstrate pharmacological levels of cortisol have a highly significant negative effect on circulating testosterone concentrations [27,28]. However, the findings of another study [29] indicated a significant negative relationship between cortisol and total testosterone in exercise and a significant positive relationship between cortisol and free testosterone following exercise; possibly due to an adrenal cortex contribution of free testosterone or disassociation of free testosterone from sex hormone binding globulin. They suggested that the in vivo relationships between cortisol and testosterone were associative and not causal in nature. ...
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Introduction: In animals, there is a strong positive relationship between testosterone and aggression. However, in humans, especially in adolescents, reports are less consistent. This study aims to investigate the gender related relationships among salivary cortisol and testosterone hormones and self-esteem and aggressiveness in university students. Materials and Method: A total of 91 Nigerian university students were involved in the study. Participants were 23 men and 68 women who were 17-25 years of age. Salivary assay of cortisol and testosterone were done using Enzyme-linked Immunosorbent Assay Kits. The Rosenberg Self-esteem Scale was used to screen for self-esteem. Aggression scale was used to assess the points associated with aggressiveness. Results: Men had higher salivary cortisol, testosterone levels and aggressiveness score compared to women. There were positive correlations between salivary cortisol and salivary testosterone and between salivary testosterone and aggressiveness score in total sample. Also, there was positive correlation between salivary testosterone and aggressiveness in male subjects and there was positive correlation between salivary cortisol and salivary testosterone in female subjects. Conclusion: Low aggressiveness in female subjects can be due to the positive correlation between cortisol and testosterone or the parallel secretion of these two hormones by adrenal cortex. It can be stated that cortisol has a moderating effect on the relationship between testosterone and aggression in especially female subjects. Also, it can be stated that cortisol inhibits the positive enhancing effect of testosterone on aggressiveness in women.
... There are numerous research studies reporting findings of exerciseinduced short-term increases in cortisol levels (see review articles-references (74, 78)), as well as these acute elevations in cortisol from an exercise session being associated with decreases in testosterone (72,80,81). Furthermore, evidence exists for circulating testosterone and cortisol to be negatively associated with athletes even in the resting, basal state (82). In these scenarios the inhibitory effect of cortisol appears twofold; i.e., to impact LH and FSH via GnRH suppression as well as a compromise of Leydig cell function via direct steroidogenesis inhibition (79,83). ...
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For decades researchers have reported men who engaged in intensive exercise training can develop low resting testosterone levels, alterations in their hypothalamic-pituitary-gonadal (HPG) axis, and display hypogonadism. Recently there is renewed interest in this topic since the International Olympic Committee (IOC) Medical Commission coined the term "Relative Energy Deficiency in Sports" (RED-S) as clinical terminology to address both the female-male occurrences of reproductive system health disruptions associated with exercise. This IOC Commission action attempted to move beyond the sex-specific terminology of the "Female Athlete Triad" (Triad) and heighten awareness/realization that some athletic men do have reproductive related physiologic disturbances such as lowered sex hormone levels, HPG regulatory axis alterations, and low bone mineral density similar to Triad women. There are elements in the development and symptomology of exercise-related male hypogonadism that mirror closely that of women experiencing the Triad/RED-S, but evidence also exists that dissimilarities exist between the sexes on this issue. Our research group postulates that the inconsistency and differences in the male findings in relation to women with Triad/RED-S are not just due to sex dimorphism, but that there are varying forms of exercise-related reproductive disruptions existing in athletic men resulting in them displaying a relative hypogonadism condition. Specifically, such conditions in men may derive acutely and be associated with low energy availability (Triad/RED-S) or excessive training load (overtraining) and appear transient in nature, and resolve with appropriate clinical interventions. However, manifestations of a more chronic based hypogonadism that persists on a more permanent basis (years) exist and is termed the "Exercise Hypogonadal Male Condition." This article presents an up-to-date overview of the various types of acute and chronic relative hypogonadism found in athletic, exercising men and proposes mechanistic models of how these various forms of exercise relative hypogonadism develop.
... In the present study, although a significant increase in cortisol levels was observed in all study groups between T1 and T2, only a significant increase in testosterone levels was observed in CrM-HMBG. These changes resulted in a significant decrease of the T/C ratio in PLG, CrMG, and HMBG, which indicates greater accumulated stress/fatigue [67]. The differences in testosterone levels could be due to the duration of the intervention (six weeks in Crowe and O'Connor's study [45] vs. 10 weeks in the present study), given that testosterone requires long-term intervention to produce significant changes [11,12]. ...
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Creatine monohydrate (CrM) and β-hydroxy β-methylbutyrate (HMB) are widely studied ergogenic aids. However, both supplements are usually studied in an isolated manner. The few studies that have investigated the effect of combining both supplements on exercise-induced muscle damage (EIMD) and hormone status have reported controversial results. Therefore, the main purpose of this study was to determine the effect and degree of potentiation of 10 weeks of CrM plus HMB supplementation on EIMD and anabolic/catabolic hormones. This study was a double-blind, placebo-controlled trial where participants (n = 28) were randomized into four different groups: placebo group (PLG; n = 7), CrM group (CrMG; 0.04 g/kg/day of CrM; n = 7), HMB group (HMBG; 3 g/day of HMB; n = 7), and CrM-HMB group (CrM-HMBG; 0.04 g/kg/day of CrM plus 3 g/day of HMB; n = 7). Before (baseline, T1) and after 10 weeks of supplementation (T2), blood samples were collected from all rowers. There were no significant differences in the EIMD markers (aspartate aminotransferase, lactate dehydrogenase, and creatine kinase) among groups. However, we observed significant differences in CrM-HMBG with respect to PLG, CrMG, and HMBG on testosterone (p = 0.006; η 2 p = 0.454) and the testosterone/cortisol ratio (T/C; p = 0.032; η 2 p = 0.349). Moreover, we found a synergistic effect of combined supplementation on testosterone (CrM-HMBG = −63.85% vs. CrMG + HMBG = −37.89%) and T/C (CrM-HMBG = 680% vs. CrMG + HMBG = 57.68%) and an antagonistic effect on cortisol (CrM-HMBG = 131.55% vs. CrMG + HMBG = 389.99%). In summary, the combination of CrM plus HMB showed an increase in testosterone and T/C compared with the other groups after 10 weeks of supplementation. Moreover, this combination presented a synergistic effect on testosterone and T/C and an antagonistic effect on cortisol compared with the sum of individual or isolated supplementation.
... It has been reported that a negative relationship exists between cortisol and testosterone. Elevated cortisol levels were associated with decreased testosterone levels during exercise or even in disease status such as ischemic heart disease [33,34]. Vitamin C supplementation has also been reported to attenuate cortisol responses following psychological or physical stressors [35]. ...
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Purpose: Male fertility is multifaceted and its integrity is as well multifactorial. Normal spermatogenesis is dependent on competent testicular function; namely normal anatomy, histology, physiology and hormonal regulation. Lifestyle stressors, including sleep interruption and even deprivation, have been shown to seriously impact male fertility. We studied here both the effects and the possible underlying mechanisms of vitamin C on male fertility in sleep deprived rats. Methods: Thirty male Wistar albino rats were used in the present study. Rats were divided (10/group) into: control (remained in their cages with free access to food and water), sleep deprivation (SD) group (subjected to paradoxical sleep deprivation for 5 consequent days, rats received intra-peritoneal injections of vehicle daily throughout the sleep deprivation), and sleep deprivation vitamin C-treated (SDC) group (subjected to sleep deprivation for 5 consequent days with concomitant intra-peritoneal injections of 100 mg/kg/day vitamin C). Sperm analysis, hormonal assay, and measurement of serum oxidative stress and inflammatory markers were performed. Testicular gene expression of Nrf2 and NF-κβ was assessed. Structural changes were evaluated by testicular histopathology, while PCNA immunostaining was conducted to assess spermatogenesis. Results: Sleep deprivation had significantly altered sperm motility, viability, morphology and count. Serum levels of cortisol, corticosterone, IL-6, IL-17, MDA were increased, while testosterone and TAC levels were decreased. Testicular gene expression of Nrf2 was decreased, while NF-κβ was increased. Sleep deprivation caused structural changes in the testes, and PCNA immunostaining showed defective spermatogenesis. Administration of vitamin C significantly countered sleep deprivation induced deterioration in male fertility parameters. Conclusion: Treatment with vitamin C enhanced booth testicular structure and function in sleep deprived rats. Vitamin C could be a potential fertility enhancer against lifestyle stressors.
... Moreover, it should be noted that several studies reported a negative correlation between cortisol and testosterone concentrations after physical exertion. An increase of cortisol activity induced by physical exertion may lead to a reduction in testosterone concentration in blood [32][33][34]. The ratio of serum cortisol (catabolic hormone) to free testosterone (anabolic hormone) is a key indicator of physical exertion and anaboliccatabolic homeostasis [35]. ...
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Introduction: In this study, we attempted to examine the effect of pelvic floor muscle training on testosterone and cortisol concentrations in elderly women with stress urinary incontinence. Material and methods: The number of participants included in the analysis was 59: 30 women in the experimental group (EG) and 29 women in the control group (CG). The EG underwent pelvic floor muscle training, whereas the CG did not receive any therapeutic intervention. In the present study the authors measured testosterone and cortisol concentrations as well as body mass index (BMI) in all study participants at the initial and final assessments. Results: The initial and final assessment results were compared and showed a statistically significant decrease in cortisol concentration and an increase in testosterone concentration in the EG. However, no statistically significant differences in the measured variables were observed in the CG at the initial and final assessments. The authors did not report any statistically significant correlations between testosterone and cortisol concentrations and the BMI score in the EG and CG. Also, statistically significant correlations between testosterone and cortisol concentrations in the EG were not apparent. Conclusions: Determination of the concentration of testosterone and cortisol is a method that may help to objectify pelvic floor muscle training outcomes in elderly women with stress urinary incontinence.
... Testosterone response may have been conditioned by the cortisol levels observed after the CF workouts. High cortisol levels in response to anaerobic exercise possibly caused a potential for inhibition of testosterone production via steroid inhibition, and thus, cortisol induced a direct suppressive effect on testosterone steroidogenesis [55]. The T/C ratio has been identi ed as an indicator of anabolic/catabolic status during exercise [56]. ...
Preprint
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Background: Acute beetroot juice (BJ) intake has shown to enhance aerobic and anaerobic performance. However, no studies have evaluated the effects of BJ intake on CrossFit (CF) performance by linking hormonal, metabolic, and mechanical responses. The purpose of this study was to determine the causal physiological association between hormonal, metabolic and mechanical responses, and CF workouts performance after acute BJ intake. Methods: Twelve well-trained male practitioners undertook a CF workout after drinking 140 mL of BJ (~ 12.8 mmol NO3⁻) or placebo. The two experimental conditions (BJ or placebo) were administered using a randomized, double-blind, crossover design. The CF workout consisted of repeating the same exercise routine twice: Wall ball (WB) shots plus full back squat (FBS) with 3-min rest (1st routine) or without rest (2nd routine) between the two exercises. A 3-min rest was established between the two exercise routines. Results: An interaction effect was observed in the number of repetitions performed (p = 0.04). The Bonferroni test determined a higher number of repetitions after BJ than placebo intake when a 3-min rest between WB and FBS (1st routine) was established (p = 0.007). An interaction effect was detected in cortisol response (p = 0.04). Cortisol showed a higher increase after BJ compared to placebo intake (76% vs. 36%, respectively). No interaction effect was observed in the testosterone and testosterone/cortisol ratio (p > 0.05). A significant interaction effect was found in oxygen saturation (p = 0.01). A greater oxygen saturation drop was observed in BJ compared to placebo (p < 0.05). An interaction effect was verified in muscular fatigue (p = 0.03) with a higher muscular fatigue being observed with BJ than placebo (p = 0.02). Conclusions: BJ intake improved anaerobic performance only after the recovery time between exercises. This increase in performance in the first routine probably generated greater hypoxia in the muscle mass involved, possibly conditioning post-exercise performance. This was observed with a fall in oxygen saturation and in muscle fatigue measured at the end of the CF workout. The greatest perceived changes in cortisol levels after BJ intake could be attributed to the nitrate-nitrite-nitric oxide pathway
... Testosterone response may have been conditioned by the cortisol levels observed after the CF workouts. High cortisol levels in response to anaerobic exercise possibly caused a potential for inhibition of testosterone production via steroid inhibition, and thus, cortisol induced a direct suppressive effect on testosterone steroidogenesis [61]. ...
Preprint
Full-text available
Background: Acute beetroot juice (BJ) intake has shown to enhance aerobic and anaerobic performance. However, no studies have evaluated the effects of BJ intake on CrossFit (CF) performance by linking hormonal, metabolic, and mechanical responses. The purpose of this study was to determine the causal physiological association between hormonal, metabolic and mechanical responses, and CF workouts performance after acute BJ intake. Methods: Twelve well-trained male practitioners undertook a CF workout after drinking 140 mL of BJ (~ 12.8 mmol NO3⁻) or placebo. The two experimental conditions (BJ or placebo) were administered using a randomized, double-blind, crossover design. The CF workout consisted of repeating the same exercise routine twice: Wall ball (WB) shots plus full back squat (FBS) with 3-min rest (1st routine) or without rest (2nd routine) between the two exercises. A 3-min rest was established between the two exercise routines. Results: An interaction effect was observed in the number of repetitions performed (p = 0.04). The Bonferroni test determined a higher number of repetitions after BJ than placebo intake when a 3-min rest between WB and FBS (1st routine) was established (p = 0.007). An interaction effect was detected in cortisol response (p = 0.04). Cortisol showed a higher increase after BJ compared to placebo intake (76% vs. 36%, respectively). No interaction effect was observed in the testosterone and testosterone/cortisol ratio (p > 0.05). A significant interaction effect was found in oxygen saturation (p = 0.01). A greater oxygen saturation drop was observed in BJ compared to placebo (p < 0.05). An interaction effect was verified in muscular fatigue (p = 0.03) with a higher muscular fatigue being observed with BJ than placebo (p = 0.02). Conclusions: BJ intake improved anaerobic performance only after the recovery time between exercises. This increase in performance in the first routine probably generated greater hypoxia in the muscle mass involved, possibly conditioning post-exercise performance. This was observed with a fall in oxygen saturation and in muscle fatigue measured at the end of the CF workout. The greatest perceived changes in cortisol levels after BJ intake could be attributed to the nitrate-nitrite-nitric oxide pathway
... Our results support those of past investigations showing that amino acid consumption may play a role in reducing exercise-induced increases in cortisol (33). Cortisol, is a catabolic hormone and basic glucocorticoid form in humans, secreted from the adrenal cortex in response to psychological and physical stress (34). During cortisol elevates in exercise, impacts of this hormone happen after exercise within the early recovery. ...
... En este estudio, aunque se observó un aumento significativo en los niveles de C en todos los grupos de estudio entre T1 y T2, solo se observó un aumento significativo en los niveles de T en CrM-HMBG. Estos cambios resultaron en una disminución significativa de la relación T/C en PLG, CrMG y HMBG, lo que indica una mayor estés/fatiga acumulada [198]. Las diferencias en los niveles de T podrían deberse a la duración de la intervención (6 semanas en el estudio de Crowe y O'Connor [148] a diferencia de las 10 semanas en el presente estudio), dado que la T requiere una intervención a largo plazo para producir cambios significativos [40,41]. ...
Thesis
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El monohidrato de creatina (CrM) y el β-hidroxi β-metilbutirato (HMB) son suplementos deportivos ampliamente estudiados. Sin embargo, no está claro cómo actúan cuando se utilizan conjuntamente en el ámbito deportivo. Hay que añadir que la incógnita es todavía mayor, cuando hablamos de un deporte de carácter predominantemente aeróbico como el remo. Los objetivos de esta tesis han sido: 1) determinar mediante una revisión sistemática la eficacia de mezclar CrM más HMB en comparación con sus efectos aislados sobre el rendimiento deportivo, la composición corporal, los marcadores de daño muscular inducidos por el ejercicio (EIMD) y las hormonas anabólico-catabólicas. 2) determinar la eficacia y el grado de potenciación de 10 semanas de suplementación con CrM más HMB en el rendimiento deportivo, que se midió mediante una prueba incremental en remeros tradicionales de élite masculinos. 3) determinar el efecto y el grado de potenciación de 10 semanas de suplementación con CrM más HMB en los EIMD y hormonas anabólicas/catabólicas. En base a los objetivos planteados, los principales resultados de la tesis indican que: 1) La combinación de CrM más 3 g/día de HMB durante 1–6 semanas podría producir efectos positivos en el rendimiento deportivo (fuerza y rendimiento anaeróbico) y durante 4 semanas en la composición corporal (aumento de grasa masa libre y disminución de la masa grasa). 2) La ingesta de CrM más HMB durante 10 semanas mostró un efecto sinérgico sobre la potencia aeróbica durante una prueba incremental. 3) La combinación de CrM más HMB presentó un efecto sinérgico sobre la testosterona y la ratio testosterona/cortisol y un efecto antagonista sobre el cortisol en comparación con la suma de la suplementación individual o aislada. Las conclusiones obtenidas en la presente tesis doctoral indican que la combinación de estos dos suplementos puede ser de gran ayuda para los profesionales que rodean al deportista para mejorar el rendimiento aeróbico y la recuperación.
... In many respects, cortisol is biochemically opposed to T, as the administration of exogenous cortisol lowers T (Cumming et al., 1983). Also, environmental stressors such as exercise reciprocally increase cortisol and decrease total testosterone (TT) (Brownlee et al., 2005). Similarly, the reverse relationship between cortisol and chronic disease risk is observed, with higher levels being associated with an increased risk of cardiovascular disease mortality (Vogelzangs et al., 2010). ...
Article
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Background: Low-carbohydrate diets may have endocrine effects, although individual studies are conflicting. Therefore, a review was conducted on the effects of low- versus high-carbohydrate diets on men's testosterone and cortisol. Methods: The review was registered on PROSPERO (CRD42021255957). The inclusion criteria were: intervention study, healthy adult males, and low-carbohydrate diet: ≤35% carbohydrate. Eight databases were searched from conception to May 2021. Cochrane's risk of bias tool was used for quality assessment. Random-effects, meta-analyses using standardized mean differences and 95% confidence intervals, were performed with Review Manager. Subgroup analyses were conducted for diet duration, protein intake, and exercise duration. Results: Twenty-seven studies were included, with a total of 309 participants. Short-term (<3 weeks), low- versus high-carbohydrate diets moderately increased resting cortisol (0.41 [0.16, 0.66], p < 0.01). Whereas, long-term (≥3 weeks), low-carbohydrate diets had no consistent effect on resting cortisol. Low- versus high-carbohydrate diets resulted in much higher post-exercise cortisol, after long-duration exercise (≥20 min): 0 h (0.78 [0.47, 1.1], p < 0.01), 1 h (0.81 [0.31, 1.31], p < 0.01), and 2 h (0.82 [0.33, 1.3], p < 0.01). Moderate-protein (<35%), low-carbohydrate diets had no consistent effect on resting total testosterone, however high-protein (≥35%), low-carbohydrate diets greatly decreased resting (−1.08 [−1.67, −0.48], p < 0.01) and post-exercise total testosterone (−1.01 [−2, −0.01] p = 0.05). Conclusions: Resting and post-exercise cortisol increase during the first 3 weeks of a low-carbohydrate diet. Afterwards, resting cortisol appears to return to baseline, whilst post-exercise cortisol remains elevated. High-protein diets cause a large decrease in resting total testosterone (∼5.23 nmol/L).
... The response to stress activates the hypothalamic-pituitary-adrenal axis and releases cortisol that possibly affected semen quality (Curley et al., 2008). High glucocorticoid levels decrease the production and secretion of testosterone from the Leydig cells and spermatogenesis (Brownlee et al., 2005), a process of division and differentiation of germ cells into spermatozoa (Johnson et al., 2000). Any change in this process has a negative effect on the semen quality such as sperm count, percentage of motile sperm, and percentage of morphologically normal sperm, which is observed in the Rottweiler breed (Janevic et al., 2014;Faeza et al., 2019). ...
Article
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The use of dogs in military work environments has always aroused great interest in the general population and determining the stress levels they go through is extremely important to maintain their welfare. The aim of this research was to evaluate if the work shifts in military working dogs leads to stress conditions and if this working influences on the reproductive performance and life quality. The study was conducted at the Military Police Kennel located at Campinas, Sao Paulo, Brazil. Eight male dogs of four different breeds (German Shepherd, Belgian Malinois Shepherd, Doberman, and Rottweiler) were evaluated during two different shifts: Working Shifts: animals working 12 hours a day with 2 hour-interval; and Control Shifts: animals that were on their day off (36 hours). Saliva samples were collected for cortisol analysis at the control and working shifts. The study was carried out over 60 days and analyzed behavior, physiology, and reproduction quality. Saliva samples, behavior observation of stereotyping, resting and moving activities and semen analysis were collected by digital stimulation (for combined second and third fractions). The salivary cortisol levels during the control and working shifts were between 0.361-0.438 and 0.312-0.592 µg/dL, respectively; the highest values were found at the end of working shifts. The animals were resting during most of the observation period, but few showed stereotypic behaviors. The testicular consistency was firm and semen parameters were within the normal values in German Shepherd, Belgian Malinois Shepherd, and Doberman dogs. However, Rottweiler dogs had a higher rate of sperm abnormalities, higher salivary cortisol levels, and more stereotypic behaviors. Nevertheless this work highlights the importance of further research relating reproduction and cortisol levels in military dogs.
... Moreover, it has been demonstrated that skeletal muscle has the capacity to store, transport and metabolize NO3 − and NO₂ − [68]. Therefore, chronic supplementation with NO precursor supplements (CIT and BR) would increase the levels of NO3 − stored in skeletal muscle that is beneficial for NO production [69]. All these mentioned mechanisms could probably work in a complementary manner by enhancing endogenous recovery. ...
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Simple Summary: Recovery is one of the main elements in achieving adequate athletic performance. Various supplements have been used for this purpose. Citrulline (CIT) and Nitrate-Rich Beetroot Extract (BR) are so-called nitric oxide precursor supplements that have shown an ergogenic effect on sports performance when used on a short-term, individual basis. These supplements appear to have other pathways that may promote athletic performance. The purpose of this study was to assess the effect of a co-supplementation for 9 weeks of 3 g/day of CIT plus 2.1 g/day of BR (300 mg/day of nitrates) on recovery by exercise-induced muscle damage markers (EIMD), anabolic/cat-abolic hormones and distance covered in the Cooper test (CP). Thirty-two male triathletes were randomized into 4 groups of 8 in this double-blind, placebo-controlled trial: placebo group, CIT group, BR group and CIT-BR group. Blood samples and CP were collected at baseline and after 9 weeks. The main conclusions were the combination of 3 g/day of CIT plus 2.1 g/day of BR (300 mg/day of NO3 −) supplementation for 9 weeks did not present any benefit for EIMD. However, CIT-BR improved recovery status by preventing an increase in cortisol and showing an increase in Tes-tosterone/Cortisol ratio and distance covered in the CP. Abstract: Citrulline (CIT) and nitrate-rich beetroot extract (BR) are widely studied ergogenic aids. Nevertheless, both supplements have been studied in short-term trials and separately. To the best of the authors' knowledge, the effects of combining CIT and BR supplementation on recovery status observed by distance covered in the Cooper test, exercise-induced muscle damage (EIMD) and an-abolic/catabolic hormone status have not been investigated to date. Therefore, the main purpose of this research was to assess the effect of the long-term (9 weeks) mixture of 3 g/day of CIT plus 2.1 g/day of BR (300 mg/day of nitrates (NO3 −)) supplementation on recovery by distance covered in the Cooper test, EIMD markers (urea, creatinine, AST, ALT, GGT, LDH and CK) and Citation: Burgos, J.; Viribay, A.; Calleja-González, J.; Fernández-Lázaro, D.; Olasagasti-Ibargoien, J.; Seco-Calvo, J.; Mielgo-Ayuso, J. Publisher's Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons At-tribution (CC BY) license (http://crea-tivecommons.org/licenses/by/4.0/). Biology 2022, 11, 75 2 of 17 anabolic/catabolic hormones (testosterone, cortisol and testosterone/cortisol ratio (T/C)) in male trained triathletes. Thirty-two triathletes were randomized into four different groups of eight triath-letes in this double-blind, placebo-controlled trial: placebo group (PLG), CIT group (CITG; 3 g/day of CIT), BR group (BRG; 2.1 g/day of BR (300 mg/day of NO3 −)) and CIT-BR group (CIT-BRG; 3 g/day of CIT plus 2.1 g/day of BR (300 mg/day of NO3 −)). Distance covered in the Cooper test and blood samples were collected from all participants at baseline (T1) and after 9 weeks of supplementation (T2). There were no significant differences in the interaction between group and time in EIMD markers (urea, creatinine, AST, ALT, GGT, LDH and CK) (p > 0.05). However, significant differences were observed in the group-by-time interaction in distance covered in the Cooper test (p = 0.002; η 2 p = 0.418), cortisol (p = 0.044; η 2 p = 0.247) and T/C (p = 0.005; η²p = 0.359). Concretely, significant differences were observed in distance covered in the Cooper test percentage of change (p = 0.002; η²p = 0.418) between CIT-BRG and PLG and CITG, in cortisol percentage change (p = 0.049; η 2 p = 0.257) and in T/C percentage change (p = 0.018; η 2 p = 0.297) between CIT-BRG and PLG. In conclusion, the combination of 3 g/day of CIT plus 2.1 g/day of BR (300 mg/day of NO3 −) supplementation for 9 weeks did not present any benefit for EIMD. However, CIT + BR improved recovery status by preventing an increase in cortisol and showing an increase in distance covered in the Cooper test and T/C.
... Moreover, it has been demonstrated that skeletal muscle has the capacity to store, transport and metabolize NO3 − and NO₂ − [68]. Therefore, chronic supplementation with NO precursor supplements (CIT and BR) would increase the levels of NO3 − stored in skeletal muscle that is beneficial for NO production [69]. All these mentioned mechanisms could probably work in a complementary manner by enhancing endogenous recovery. ...
Article
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Simple Summary: Recovery is one of the main elements in achieving adequate athletic performance. Various supplements have been used for this purpose. Citrulline (CIT) and Nitrate-Rich Beetroot Extract (BR) are so-called nitric oxide precursor supplements that have shown an ergogenic effect on sports performance when used on a short-term, individual basis. These supplements appear to have other pathways that may promote athletic performance. The purpose of this study was to assess the effect of a co-supplementation for 9 weeks of 3 g/day of CIT plus 2.1 g/day of BR (300 mg/day of nitrates) on recovery by exercise-induced muscle damage markers (EIMD), anabolic/cat-abolic hormones and distance covered in the Cooper test (CP). Thirty-two male triathletes were randomized into 4 groups of 8 in this double-blind, placebo-controlled trial: placebo group, CIT group, BR group and CIT-BR group. Blood samples and CP were collected at baseline and after 9 weeks. The main conclusions were the combination of 3 g/day of CIT plus 2.1 g/day of BR (300 mg/day of NO3 −) supplementation for 9 weeks did not present any benefit for EIMD. However, CIT-BR improved recovery status by preventing an increase in cortisol and showing an increase in Tes-tosterone/Cortisol ratio and distance covered in the CP. Abstract: Citrulline (CIT) and nitrate-rich beetroot extract (BR) are widely studied ergogenic aids. Nevertheless, both supplements have been studied in short-term trials and separately. To the best of the authors' knowledge, the effects of combining CIT and BR supplementation on recovery status observed by distance covered in the Cooper test, exercise-induced muscle damage (EIMD) and an-abolic/catabolic hormone status have not been investigated to date. Therefore, the main purpose of this research was to assess the effect of the long-term (9 weeks) mixture of 3 g/day of CIT plus 2.1 g/day of BR (300 mg/day of nitrates (NO3 −)) supplementation on recovery by distance covered in the Cooper test, EIMD markers (urea, creatinine, AST, ALT, GGT, LDH and CK) and Citation: Burgos, J.; Viribay, A.; Calleja-González, J.; Fernández-Lázaro, D.; Olasagasti-Ibargoien, J.; Seco-Calvo, J.; Mielgo-Ayuso, J. Publisher's Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons At-tribution (CC BY) license (http://crea-tivecommons.org/licenses/by/4.0/). Biology 2022, 11, 75 2 of 17 anabolic/catabolic hormones (testosterone, cortisol and testosterone/cortisol ratio (T/C)) in male trained triathletes. Thirty-two triathletes were randomized into four different groups of eight triath-letes in this double-blind, placebo-controlled trial: placebo group (PLG), CIT group (CITG; 3 g/day of CIT), BR group (BRG; 2.1 g/day of BR (300 mg/day of NO3 −)) and CIT-BR group (CIT-BRG; 3 g/day of CIT plus 2.1 g/day of BR (300 mg/day of NO3 −)). Distance covered in the Cooper test and blood samples were collected from all participants at baseline (T1) and after 9 weeks of supplementation (T2). There were no significant differences in the interaction between group and time in EIMD markers (urea, creatinine, AST, ALT, GGT, LDH and CK) (p > 0.05). However, significant differences were observed in the group-by-time interaction in distance covered in the Cooper test (p = 0.002; η 2 p = 0.418), cortisol (p = 0.044; η 2 p = 0.247) and T/C (p = 0.005; η²p = 0.359). Concretely, significant differences were observed in distance covered in the Cooper test percentage of change (p = 0.002; η²p = 0.418) between CIT-BRG and PLG and CITG, in cortisol percentage change (p = 0.049; η 2 p = 0.257) and in T/C percentage change (p = 0.018; η 2 p = 0.297) between CIT-BRG and PLG. In conclusion, the combination of 3 g/day of CIT plus 2.1 g/day of BR (300 mg/day of NO3 −) supplementation for 9 weeks did not present any benefit for EIMD. However, CIT + BR improved recovery status by preventing an increase in cortisol and showing an increase in distance covered in the Cooper test and T/C.
... In fact, it has been evidenced that skeletal muscle has the capacity to accumulate, transfer and metabolize NO 3 − and nitrite [67]. Therefore, prolonged supplementation with this type of ergogenic aid (BR) would increase the levels of stored NO 3 − , favourable for the production of NO and, subsequently, associated with long-term adaptations [68]. In this regard, acute or chronic administration of NO 3 − by athletes has also been demonstrated to improve the contractile properties of human skeletal muscle, particularly the twitch force, rate of force development, estimated maximal shortening velocity and maximal power of muscle [28]. ...
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Citrulline (CIT) and nitrate-rich beetroot extract (BR) are ergogenic aids and nitric oxide (NO) precursors. In addition, both supplements seem to have other actions at the level of muscle metabolism that can benefit strength and aerobic power performance. Both supplements have been studied in numerous investigations in isolation. However, scientific evidence combining both supplements is scarce, and to the best of the authors’ knowledge, there is no current study of endurance athletes. Therefore, the main purpose of this study was to determine the effect of 9 weeks of CIT plus BR supplementation on maximal and endurance-strength performance and aerobic power in male triathletes. This study was a randomized double-blind, placebo-controlled trial where participants (n = 32) were randomized into four different groups: placebo group (PLG; n = 8), CIT plus BR group (CIT- BRG; 3 g/kg/day of CIT plus 3 mg/kg/day of nitrates (NO3 −); n = 8), CIT group (CITG; 3 g/kg/day; n = 8) and BR group (BRG; 3 mg/kg/day of NO3−; n = 8). Before (T1) and after 9 weeks (T2), four physical condition tests were carried out in order to assess sport performance: the horizontal jump test (HJUMP), handgrip dynamometer test, 1-min abdominal tests (1-MAT) and finally, the Cooper test. Although, no significant interactions (time × supplementation groups) were found for the strength tests (p > 0.05), the CIT- BRG supplementation presented a trend on HJUMP and 1-MAT tests confirmed by significant increase between two study moments in CIT-BRG. Likewise, CIT-BRG presented significant interactions in the aerobic power test confirmed by this group’s improve estimated VO2max during the study with respect to the other study groups (p = 0.002; η 2p = 0.418). In summary, supplementing with 3 g/day of CIT and 2.1 g/day of BR (300 mg/day of NO3 −) for 9 weeks could increase maximal and endurance strength. Furthermore, when compared to CIT or BR supplementation alone, this combination improved performance in tests related to aerobic power.
... Then, it is not only the psychological experience of challenge or status change that is known to elicit T responses, but also physical effort per se (see [70]). Conversely, physical exertion during athletic competitions can inhibit T responses, possibly mediated through cortisol responses [76]. Consequently, some studies have controlled for physical effort by taking lactate measurements or including a non-competitive condition (e.g., an ergometer test) in the design [59,64]. ...
Article
Two main hypotheses have been formulated to explain short-term testosterone responses to competitions. The challenge hypothesis and the biosocial model of status make different predictions concerning the point of time, direction, and meaning of hormonal changes. This field study investigated whether testosterone reacts to experiences of challenge during the early stages of a competition or to experiences of status change as a consequence of the competition's outcome. Over a period of 28 days, approximately 2000 salivary testosterone samples were collected from 82 football fans (53% men), while they were watching the matches of their favorite national team during the 2014 World Cup. Conducting repeated measurements across seven competitive events (i.e., matches) and over the course of each match allowed us to split vicarious experiences during each competition into phases of challenge and phases of status change. For both sexes, the results revealed discriminable testosterone trajectories depending on whether the fans experienced highly competitive matches or quick victories. By use of a discontinuous change model, maximal testosterone increases were detected during experiences of challenge. In contrast, a return to pre-contest baseline testosterone levels was initiated as soon as a status gain became certain. Testosterone responsiveness was partly moderated by the subjective importance of the competitive event. Thus, this study provides evidence in favor of the challenge hypothesis and emphasizes the value of conducting high-resolution within-subject designs to further explain the adaptive meaning of androgen responses.
... It has been reported that a negative relationship exists between cortisol and testosterone. Elevated cortisol levels were associated with decreased testosterone levels during exercise or even in disease status such as ischemic heart disease [33,34]. Vitamin C supplementation has also been reported to attenuate cortisol responses following psychological or physical stressors [35]. ...
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Background The prevalence of hypertension and obesity has increased significantly in recent decades. Hypertension and obesity often coexist, and both are associated with increased cardiovascular mortality. Obese hypertensive patients usually require special anti-hypertensive treatment strategy due to the increased risk of treatment resistance. Molecules that can target both obesity and hypertension underlying pathologies should get more attention. Herein, we evaluated the therapeutic effects of telmisartan, with special interest in visceral adipose tissue dysfunction, in obesity-related hypertension rat model. Methods Thirty male Wistar rats weighing 150–200 g were equally divided into: 1—Control group (fed normal laboratory diet for 24 weeks), 2—Diet-induced obesity group (DIO, fed high fat diet for 24 weeks), and 3—Diet-induced obesity treated with telmisartan group (DIO + Tel, fed high fat diet and received telmisartan for 24 weeks). At the end of the study, anthropometrical parameters were evaluated. Systolic blood pressure and heart rate were measured. Blood samples were collected for the measurement of serum lipids, adipokines, cardiac, renal, inflammatory, and oxidative stress biomarkers. Kidneys were removed and used for histopathological studies, and visceral adipose tissue was utilized for histopathological, immunohistochemical and RT-PCR studies. Results High fat diet resulted in obesity-related changes in anthropometrical parameters, elevation of blood pressure, increase in heart rate, higher serum levels of cardiac, inflammatory and kidney function biomarkers, with altered serum lipids, adipokines and oxidative stress markers. Morphological changes (H&E and PAS-stained sections) were noticed in kidneys and visceral adipose tissue. Immunohistochemistry and RT-PCR studies confirmed adipose tissue dysfunction and over-expression of inflammatory and oxidative stress proteins. Telmisartan countered obesity-induced alterations in cardiovascular, renal, and adipose tissue functions. Conclusion Adipose tissue dysfunction could be the core pathophysiology of obesity-related hypertension. Besides its anti-hypertensive effect, telmisartan had profound actions on visceral adipose tissue structure and function. Attention should be given to polymodal molecules targeting adipose tissue-related disorders.
... Blood samples were collected between 9:30 and 11:00. Previous research has shown no effect of this collection time on individual differences in testosterone levels (e.g., Brownlee et al., 2005;Borráz-León et al., 2018, 2019. Testosterone levels were assessed using an in-house competitive chemiluminescent enzyme immunoassay with commercially available kits . ...
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The development of costly traits such as immune function and secondary sexual traits is constrained by resource availability. The quality of developmental conditions and the availability of resources in ontogeny may therefore influence immune system functions and other biological traits. We analyzed causal pathways between family socioeconomic position, strength of immune response, and five physiological biomarkers in young Latvian men (n = 93) using structural equation modeling. Men from wealthier families had higher testosterone levels (r = 0.280), stronger immune response (r = 0.551), and higher facial attractiveness (r = 0.300). There were weak, non-significant correlations between family income, body fat percentage (r = -0.147), and fluctuating asymmetry (r = -0.159). Testosterone partially (33.8%) mediated the effect of family income on facial masculinity. Testosterone (positively) and adiposity (negatively) partially (4%) mediated the relationship between family income and immune function. Higher facial masculinity, higher facial symmetry, and lower adiposity were reliable and independent cues of better immune function (R² = 0.238) in a larger sample of young Latvian men (N = 146). Resource availability in ontogeny has an important role for the development of immune function and physical appearance, and it is a key parameter to be included in human eco-immunological research.
... Cortisol (C) is a catabolic hormone regulated by the hypothalamus-hypophysis-adrenal axis that facilitates the mobilization of substrates during exercise to improve athletic performance [14], and its concentrations can be kept high up to 48 h after exhaustive long-term exercise, interfering with the recovery process [1]. Few studies relating TM with this hormone were found; Soria et al. found that increases in C concentrations in trained athletes positively correlated with increases in Zn and Se levels, which suggests that it occurs because of the participation of these elements in the prevention of oxidative stress [15]. ...
... Cortisol (C) is a catabolic hormone regulated by the hypothalamus-hypophysis-adrenal axis that facilitates the mobilization of substrates during exercise to improve athletic performance [14], and its concentrations can be kept high up to 48 h after exhaustive long-term exercise, interfering with the recovery process [1]. Few studies relating TM with this hormone were found; Soria et al. found that increases in C concentrations in trained athletes positively correlated with increases in Zn and Se levels, which suggests that it occurs because of the participation of these elements in the prevention of oxidative stress [15]. ...
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Several essential trace minerals play an important role in the endocrine system; however, toxic trace minerals have a disruptive effect. The aim of this research was to determine basal concentrations and the possible correlations between trace minerals in plasma and several plasma hormones in runners. Sixty high-level male endurance runners (21 ± 3 years; 1.77 ± 0.05 m; 64.97 ± 7.36 kg) participated in the present study. Plasma hormones were analyzed using an enzyme-linked immunosorbent assay (ELISA) and plasma trace minerals were analyzed with inductively coupled plasma mass spectrometry (ICP-MS). Correlations and simple linear regression were used to assess the association between trace minerals and hormones. Plasma testosterone concentrations were inversely correlated with manganese (r = −0.543; β = −0.410; p < 0.01), selenium (r = −0.292; β = −0.024; p < 0.05), vanadium (r = −0.406; β = −1.278; p < 0.01), arsenic (r = −0.336; β = −0.142; p < 0.05), and lead (r = −0.385; β = −0.418; p < 0.01). Plasma luteinizing hormone (LH) levels were positively correlated with arsenic (r = 0.298; β = 0.327; p < 0.05) and cesium (r = 0.305; β = 2.272; p < 0.05), and negatively correlated with vanadium (r = −0.303; β = −2.467; p < 0.05). Moreover, cortisol concentrations showed significant positive correlations with cadmium (r = 0.291; β = 209.01; p < 0.05). Finally, insulin concentrations were inversely related to vanadium (r = −0.359; β = −3.982; p < 0.05). In conclusion, endurance runners living in areas with high environmental levels of toxic minerals should check their concentrations of anabolic hormones.
... Testosterone response may have been conditioned by the cortisol levels observed after the CF workouts. High cortisol levels in response to anaerobic exercise possibly caused a potential for inhibition of testosterone production via steroid inhibition, and thus, cortisol induced a direct suppressive effect on testosterone steroidogenesis [61]. ...
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Background: Acute beetroot juice (BJ) intake has shown to enhance aerobic and anaerobic performance. However, no studies have evaluated the effects of BJ intake on CrossFit (CF) performance by linking hormonal, metabolic, and mechanical responses. The purpose of this study was to determine the causal physiological association between hormonal, metabolic and mechanical responses, and CF workouts performance after acute BJ intake. Methods: Twelve well-trained male practitioners undertook a CF workout after drinking 140 mL of BJ (~ 12.8 mmol NO3⁻) or placebo. The two experimental conditions (BJ or placebo) were administered using a randomized, double-blind, crossover design. The CF workout consisted of repeating the same exercise routine twice: Wall ball (WB) shots plus full back squat (FBS) with 3-min rest (1st routine) or without rest (2nd routine) between the two exercises. A 3-min rest was established between the two exercise routines. Results: An interaction effect was observed in the number of repetitions performed (p = 0.04). The Bonferroni test determined a higher number of repetitions after BJ than placebo intake when a 3-min rest between WB and FBS (1st routine) was established (p = 0.007). An interaction effect was detected in cortisol response (p = 0.04). Cortisol showed a higher increase after BJ compared to placebo intake (76% vs. 36%, respectively). No interaction effect was observed in the testosterone and testosterone/cortisol ratio (p > 0.05). A significant interaction effect was found in oxygen saturation (p = 0.01). A greater oxygen saturation drop was observed in BJ compared to placebo (p < 0.05). An interaction effect was verified in muscular fatigue (p = 0.03) with a higher muscular fatigue being observed with BJ than placebo (p = 0.02). Conclusions: BJ intake improved anaerobic performance only after the recovery time between exercises. This increase in performance in the first routine probably generated greater hypoxia in the muscle mass involved, possibly conditioning post-exercise performance. This was observed with a fall in oxygen saturation and in muscle fatigue measured at the end of the CF workout. The greatest perceived changes in cortisol levels after BJ intake could be attributed to the nitrate-nitrite-nitric oxide pathway
Article
Background Aging is often associated with low-grade systemic inflammation and reduced anabolic hormone levels. To investigate whether lifelong exercise training can decrease the age-related low-grade inflammation and anabolic hormone levels, we examined hormonal and inflammatory parameters among highly-trained male masters athletes and age-matched non-athletes. Methods From 70 elite power and endurance master athletes – EMA (51.3 ± 8.0 yr), 32 young controls - YC (23.7 ± 3.9 yr) and 24 untrained age-matched controls - MAC (47.2 ± 8.0 yr) venous blood was drawn to measure inflammatory parameters (interleukin-6 [IL-6], tumor necrosis factor-α [TNF-α] and interleukin-10 [IL-10]) and circulating hormones (luteinizing hormone [LH], total testosterone, estradiol, sex hormone-binding globulin [SHBG] and free androgen index [FAI]). Results EMA showed a better anti-inflammatory status than MAC (higher IL-10 and IL-10/IL-6 ratio and lower IL-6), but a lower anti-inflammatory status than YC (higher TNF-α) (p < 0.05). The MAC group had lower testosterone levels compared to the YC and EMA group (p < 0.05), and lower estradiol levels and testosterone/LH ratio compared to YC (p < 0.05). In the control groups (MAC and YC), testosterone correlated negatively with age and proinflammatory parameters, and positively with anti-inflammatory parameters. Conclusion Elite master athletics elevated levels of anti-inflammatory cytokines above that seen in non-athlete peers and mitigated the age-related reduction in testosterone levels.
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Cortisol is involved in a broad range of physiological processes and enables animals to adapt to new situations and challenges. Diurnal fluctuations in circulating cortisol concentrations in elephants have been demonstrated based on samples from urine and saliva. The aims of this study were to demonstrate diurnal cortisol fluctuations based on blood samples and compare concentrations between seasons, species, and changes in reproductive hormone concentrations. Nine African (Loxodonta africana) and three Asian (Elephas maximus) elephants at two facilities in the United States were included in this study. Blood samples were collected every 2-3 h at one location and every 1-6 h at another. Peak serum concentrations of cortisol averaged 28 ng/ml for both African and Asian elephants, and diurnal cycles included a fivefold decrease from morning peak to evening nadir concentrations. Diurnal cortisol profiles varied uniquely among individual elephants. During the winter, nadir concentrations of cortisol were slightly higher, and the timing of peak concentrations was less predictable. There was no correlation between diurnal serum concentrations of progesterone and cortisol; however, a significant correlation (p = .02) was identified between serum concentrations of testosterone and cortisol when a time lag of ~2-3 h was considered. The physiological significance of the positive correlations between diurnal serum concentrations of cortisol and testosterone in male elephants remains to be determined. If cortisol concentrations are being used to evaluate elephant health or welfare, samples should be obtained at the same time each day to minimize variation due to diurnal fluctuations, and ideally seasonal variations and individuality in diurnal profiles should also be considered.
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β‐hydroxy β‐methylbutryate (HMB) is a metabolite of leucine amino acid and it has several ergogenic benefits. Previous studies also showed that it may affect beneficially the testosterone and cortisol concentration in athletes. Due to the contradiction results between studies, we aimed to conduct this meta‐analysis to assess the HMB supplementation effect on testosterone and cortisol in trained athletes. Scopus, Medline, and Google scholar were systematically searched up to August 2021. The Cochrane Collaboration tool for evaluating the risk of bias was applied for assessing the studies' quality. Random‐effects model, weighted mean difference (WMD), and 95% confidence interval (CI) were used for estimating the overall effect. Between‐study heterogeneity was evaluated applying the chi‐squared and I2 statistic. Seven articles were included in the meta‐analysis. Although the meta‐analysis generally showed that HMB consumption did not have any effect on the cortisol and testosterone concentration (p > .05), subgroup analysis based on the exercise type showed a significant decrease in the cortisol concentration in resistance training exercises (WMD = −3.30; 95% CI: −5.50, −1.10; p = .003) and a significant increase in the testosterone concentration in aerobic and anaerobic combined sports (WMD = 1.56; 95% CI: 0.07, 3.05; p = .040). The results indicate that HMB supplementation in athletes can reduce the concentration of cortisol in resistance exercises and increase the concentration of testosterone in aerobic and anaerobic combined exercises. Nevertheless, more studies are required to confirm these results. The efficacy of HMB has not been distinctly established regarding hormonal responses; thus, this systematic review and meta‐analysis provided comprehension into the potential benefits conferred by HMB supplementation to help athletes to make aware decisions on its usage and impact. In this systematic review and meta‐analysis of 7 studies (235 participants), we found that HMB consumption led to a significant decrease in cortisol and increase in testosterone concentrations after resistance exercises and aerobic and anaerobic combined activities, respectively.
Chapter
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Chapter
Several medicinal plants are traditionally used in different regions of Africa for the treatment of male infertility, sexual asthenia, erectile dysfunction, and impotency or used as an aphrodisiac. Scientific studies, mostly conducted in vitro or in animals, have proven the acclaimed traditional use of these plants to enhance sexual activities or sperm concentration, motility, and viability. Some of the mechanisms of actions associated with these plants include increased level of testosterone and the relaxation of the smooth cavernosal muscles. However, some plants were also shown to have detrimental effects on the male reproductive system. This may be due to the varying modes of plant extraction, duration of treatment, experimental design, dosage used, quality of the plant, or toxic effects. There is a need to standardize the protocols as well as to better understand the mechanism of actions of the respective plants. Further studies should be conducted using human subjects.
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Eight men were studied during graded (47, 77 and 100% of maximal oxygen uptake) and prolonged (76%) exhaustive treadmill running. Plasma catecholamine levels increased progressively with intensity and duration of exercise. Serum concentrations of thyroid-stimulating hormone (TSH) increased with increasing work loads and were 107 (58--243)% (P less than 0.001) above resting values after maximal work. Thyroxine, triiodothyronine and luteinizing hormone in serum never changed significantly. While a small increase in testosterone concentrations (13 [1--24]%) after maximal exercise probably could be explained by changes in plasma volume, a definite increase (31 [14--56]%) occurred after 40 min of prolonged exercise. During continued exercise testosterone concentrations then gradually declined. Testicular stimulation by the increased catecholamine concentrations possible contributed to the rise in testosterone concentrations, but no evidence was found for a direct catecholamine induced increase in the activity of the thyroid gland. The exercise induced increase in TSH levels possibly explians the increased thyroid hormone secretion rate, which previously has been found in individuals participating in physical training programs.
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1. Six well-trained cyclists and six untrained subjects were studied during and immediately after four successive 7 min periods of exercise at 30, 45, 60 and 75% of their maximal work capacity. 2. Venous blood samples were taken at rest, at the end of each exercise period and 5 min following the end of exercise, for estimation of metabolites in blood and plasma insulin, growth hormone, cortisol and catecholamines. 3. The results showed significant differences in the mobilization and utilization of muscle fuels between the athletically fit cyclists and the untrained group. In the cyclists, glucose, glycerol and free fatty acid concentrations were higher, but lactate, pyruvate and alanine were lower than in the untrained subjects during exercise. 4. Plasma catecholamines rose in both groups during exercise but the rise was significantly less in the racing cyclists. Plasma insulin was depressed to a greater extent in the untrained subjects during exercise and plasma glucagon rose to a greater extent during strenuous exercise and remained elevated after the end of exercise in the untrained group. Plasma human growth hormone rose to a greater extent during exercise and remained elevated after the end of exercise in the untrained group. Plasma cortisol fell at low and moderate exercise rates in both groups, but to a smaller extent in the cyclists. Cortisol values rose at higher workloads and were significantly higher in the cyclists at the end of exercise. 5. It is concluded that there are significant differences in the metabolic and hormonal responses to exercise between athletically trained and untrained individuals, even when the physically fit subjects work at the same percentage of their maximal capacity as the unfit subjects.
Article
Androgenic hormones were investigated during two separate 5-day military endurance training courses, with physical activities around the clock corresponding to a daily energy consumption of about 40,000 kilojoules, but with an intake of only 2,000 kilojoules. Altogether, the cadets slept for 1-3 h in the 5 days. Eleven male cadets participated in course I, and 10 in course II. Plasma levels of testosterone, free testosterone, dehydroepiandrosterone, 17 alpha-hydroxyprogesterone, and androstenedione decreased by 60-80% during the course. In contrast, plasma cortisol, aldosterone, progesterone, and dehydroepiandrosterone sulfate increased. LH, FSH, and ACTH decreased to about 50-80% of precourse levels. Weak correlations between plasma levels of hypophyseal and levels of adrenal and testicular hormones indicate a multifactorial regulation. In conclusion, both adrenal and testicular androgens decrease during prolonged physical strain combined with energy and sleep deficiency.
Article
The serum levels of testosterone, free testosterone, prolactin, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) were measured at rest, during 45 min of exercise on a bicycle ergometer at 50% of the subjects' previously determined maximal oxygen uptake (VO2max), and during a 30-min recovery period. Ten healthy, untrained males were used as subjects. Mean serum testosterone levels increased significantly (P less than .05) over resting values at 15 min of exercise. Mean peak serum testosterone and free testosterone were significantly (P less than .01) increased during the exercise period as compared to resting values. No significant changes were measured for serum levels of LH, FSH, or prolactin during exercise. It appeared that bicycle exercise of moderate intensity significantly increased both free and total testosterone in untrained males.
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Ten subjects exercised on a motor driven treadmill at work loads varying from 36 to 90% of their maximum aerobic power (VO2max). Plasma cortisol (F), cardiac frequency (fH), tympanic temperature (Tty), and oxygen intake (VO2) were measured during rest, exercise, and recovery periods. At the highest work load that could be maintained for 1 hr (65% to 90% VO2max) a rise in F was found of the order of 7.02±4.88 μg/100 ml (P<0.001; and a further increase (3.62 μg/100 ml) of F was observed during the first 10 min of recovery. At lower work loads, the response of F to 1 hr of exercise was variable but analysis of all the data suggests that at work levels below 50% of VO2max F usually decreased (3.74±2.27 μg/100 ml; P<0.05) and that before F began to rise a critical level of about 60% of the subject's VO2max had to be exceeded. The Tty corresponding to this work load was 37.2±0.13°C. Cortisol [1,2 3H](10 μCi) was administered to 2 subjects 30 min before a 1 hr period of exercise at 77 and 85% VO2max, respectively. The specific activity of their F continued to decline during exercise showing that the increase in F observed was due mainly to an increase in the rate of secretion and not to a decrease in the rate of removal of cortisol from the plasma. During the recovery period the specific activity of F remained nearly constant indicating the probable cessation of F secretion.
Article
The direct effects of glucocorticoids on testicular LH receptor content and steroidogenesis were studied in vivo and in vitro. Immature hypophysectomized rats were treated with varying doses of dexamethasone, corticosterone, or a synthetic progestin, 17,21-dimethyl-19-nor-pregna-4,9-diene-3,20-dione (R5020). Some animals were also treated concomitantly with FSH to prevent the hypophysectomy-induced decrease in testis functions. At the end of 5 days of treatment, testicular LH/hCG receptor content was measured by [125I]hCG binding assay while steroidogenic responsiveness was measured by in vitro incubation of testes. Dexamethasone decreased testicular LH receptor in control and FSH-treated hypophysectomized rats in doses as low as 10 microgram/day, whereas corticosterone (10 microgram/day) decreased testicular LH receptor in the FSH-treated rats but had no effect in rats not treated with FSH. In contrast, R5020 had no effect on testicular LH receptor content. In vivo treatment of hypophysectomized rats with FSH increased both basal and hCG-stimulated production of androstanediol in vitro. In contrast, concomitant treatment with dexamethasone, but not R5020, decreased both basal and hCG-stimulated testicular androstanediol production. The direct effect of glucocorticoids on testicular steroidogenic potentials was also studied in primary culture of testicular cells obtained from adult hypophysectomized rats. Treatment of cultured testicular cells wtih hCG increased testosterone production. The addition of various natural and synthetic glucocorticoids, but not R5020, to hCG-treated cells decreased testosterone production in a dose- and time-related manner (triamcinolone greater than or equal to dexamethasone greater than cortisol greater than or equal to corticosterone). A 40% decrease in testosterone production was apparent at 6 h after addition of 10(-7) M dexamethasone to hCG-treated cells. These results demonstrate the direct inhibitory effect of glucocorticoids on testicular LH receptor content and steroidogenesis, suggesting the adrenal glucocorticoids may regulate testis functions.
Article
The mechanism whereby glucocorticoids directly inhibit gonadotropin-stimulated testosterone production was studied by using primary cultures of testicular cells from adult hypophysectomized rats. Testicular cells were maintained in serum-free media with hormone treatments administered on Day 8 and media collected 48 h later for steroid and cAMP measurement. Highly purified human chorionic gonadotropin (hCG) increased testosterone production relative to controls. Concomitant administration of either natural (cortisone greater than deoxycorticosterone = aldosterone) or synthetic (dexamethasone greater than or equal to prednisolone) corticosteroids inhibited hCG-stimulated testosterone production in a dose-dependent manner. Dexamethasone at 10(-7) M decreased testosterone production by approximately 50-60% and this inhibitory effect was reversible upon removal of the glucocorticoid. In the presence or absence of a phosphodiesterase inhibitor, dexamethasone decreased hCG-stimulated cAMP production by approximately 60%. Dexamethasone also decreased testosterone production induced by cholera toxin and (Bu)2 cAMP by 43 and 63%, respectively. The dexamethasone suppression of testosterone production was accompanied by marked decreases in androstenedione (80% decrease) and 17 alpha-hydroxyprogesterone (57%) production, with a lesser effect on progesterone production (28% decrease) and no effect on pregnenolone production. Exogenous progesterone and 17 alpha-hydroxyprogesterone augmented hCG-stimulated testosterone production. Dexamethasone reduced the conversion of exogenous progesterone to testosterone by 33% but did not affect the conversion of 17 alpha-hydroxyprogesterone to androstenedione and testosterone, suggesting a specific inhibition of 17 alpha-hydroxylase. These results suggest that glucocorticoids directly suppress Leydig cell steroidogenesis by decreasing gonadotropin stimulation of cAMP production and the activity of 17 alpha-hydroxylase.
Article
The effect of acute activation of the ACTH-adrenal axis on circulating testosterone (T) levels was investigated. Elevation of circulating cortisol resulting from insulin-induced hypoglycemia or the administration of hydrocortisone was followed by a rapid decrease in serum T levels, without accompanying changes in LH or PRL. These findings suggest that hypercortisolism of endogenous or exogenous sources suppresses T secretion by a direct action on the testis. This adrenal-testicular axis may have biological implications on the reproductive adaptation to stress.
Article
Five male volunteers performed 20 min of steady-state submaximal exercise on a motor-driven treadmill at five intensities (30, 45, 60, 75, and 90% VO2 max) as well as several maximal aerobic capacity tests. Peripheral venous plasma testosterone concentrations increased above resting values in proportion to exercise intensity. However, this increase in plasma testosterone concentration was virtually equal in magnitude to the decrease in plasma volume observed consequent to the exercise bouts, resulting in no change in total testosterone contents. There was an unexpected anticipatory elevation in resting preexercise control testosterone concentration and content with increasing work intensity. The possibility that testosterone has a direct role in the organism's response to whole-body exercise is questioned.
Article
In the literature the use of plasma levels of cortisol and the testosterone and testosterone: cortisol ratio for training management is encouraged. Decreased levels of testosterone and increased levels of cortisol are suggested to be indicative for a disturbance in the anabolic-catabolic balance, which may express itself in decreased performance. The purpose of the study was to examine if the acute hormonal response to a bout of exercise and the resting levels of testosterone, luteinizing hormone (LH) and cortisol are correlated to performance in cyclists. In addition, the effect of training on this correlation was studied. Ten professional cyclists participated and measurements took place before and after a defined period of training. Maximum workload (Pmax), determined on a cycle-ergometer with a slowly increasing protocol, increased by 30 watt (p < 0.001). Workload at a lactate level of 4 mmol/l (P4) increased by 18 watt (p < 0.05). Post training, resting testosterone levels decreased from 28.8 +/- 74 nmol/l to 24.6 +/- 90 nmol/l (p < 0.05). Resting cortisol levels increased from 272 +/- 110 nmol/l pre training to 379 +/- 242 nmol/l post training (p < 0.05). These results indicate an increased catabolic state. The acute hormonal response and the resting levels of LH were not changed post training. The resting levels of testosterone and cortisol and the acute response to exercise showed no correlation with performance pre and post training. In spite of an increased catabolic state post training there was an increase in performance. These results suggest that in endurance trained cyclists, decreased testosterone levels, increased cortisol levels and a decreased testosterone: cortisol ratio does not automatically lead to a decrease in performance or a state of overtraining.
Article
Concomitant effects of temperature and pH on changes in the magnitude of the free, unbound fraction of cortisol in human serum were studied at temperatures and pH ranging from 36 to 39 degrees C and from 6.9 to 7.4, respectively. Free fraction increased with increasing temperature and decreasing pH, the two factors acting synergically: a rise in temperature from 36 to 39 degrees C caused an about 30% increase in the free fraction at pH = 7.4, and at pH 6.9--over 2.2-fold. At highest temperature-acidity combination, i.e. at 39 degrees C, pH = 6.9, the free fraction was as much as 2.5-fold higher, relative to standard conditions (ph 7.4, 37 degrees C). This implies that in vivo the free, biologically active fraction of cortisol may increase due to e.g. hyperthermia and acidosis at a constant total concentration of this hormone.
The response of total testosterone (T), free testosterone (fT), sex hormone-binding globulin (SHBG) and non-SHBG-bound testosterone (NST) to the same exercise protocol was evaluated in two different experiments on long distance runners. The first experiment was performed in the morning at 0900 hours with nine athletes, while the second was carried out in the afternoon at 1500 hours with seven athletes. During each experiment, each athlete ran for 1 h at the previously determined speed corresponding to 2 mmol.l-1 blood lactate concentration. Three venous blood samples were collected in each experiment: before exercise, at the end of running and after 1 h of recovery. Total T and SHBG showed similar responses: in the first experiment they had decreased after exercise, while in the second they had increased at the end of running. A positive correlation between total T and SHBG concentrations was found at the end of exercise. In both experiments, NST and fT had increased after exercise and decreased to initial concentrations during recovery. The results would suggest the existence of a compensatory mechanism which maintains adequate concentrations of biologically active T when total T concentrations decrease.
Article
Siberian dwarf hamsters form monogamous male-female pair bonds. Disruption of the pair bond results in increases in body mass and behavioral alterations similar to profiles seen in human atypical depression. We examined behavioral and neuroendocrine correlates associated with separation of the male from his mate. Animals were paired (n = 28 pairs) for 3 weeks, then 15 pairs were separated and 13 pairs remained as controls. Behaviors of the males were observed in a novel environment following 3 weeks of pairing and 4 weeks of separation. The 5-min behavioral test monitored exploratory, territorial behavior, and locomotor activity. Separated males showed a significant increase in body mass (p < 0.01). paralleled by an increase in food consumption (p < 0.01). Separated males had decreased seminal vesicle mass (p < 0.05) and testicular mass (p < 0.05). Behavioral analysis revealed that separated males showed no significant differences in grooming, scent-marking, alert on 2 feet, or escape behavior when compared to paired males. Separated males did show significant increases in inactivity (p < 0.05). Plasma cortisol levels were significantly increased in separated animals (p < 0.05), but there were no significant effects on testosterone. Resting levels of plasma norepinephrine and epinephrine were less in separated males, but this was significant only for norepinephrine (p < 0.05). In conclusion, separation stress was accompanied by increased hypothalamic-pituitary-adrenal axis function and decreased peripheral sympathetic nervous system activity and decreased reproductive profiles.
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Dehydroepiandrosterone (DHEA) and its sulfated metabolite DHEA-S are endogenous hormones secreted by the adrenal cortex in response to adrenocorticotrophin (ACTH). Much has been published regarding potential effects on various systems. Despite the identification of DHEA and DHEA-S more than 50 years ago, there is still considerable controversy as to their biological significance. This article reviews the metabolism and physiology of DHEA and DHEA-S, the influence of age and gender on concentrations, and changes in endogenous concentrations associated with disease states and other factors, including diet and exercise. This article is unique in that it also summarizes the influence of drugs on DHEA and DHEA-S concentrations, as well as concentrations of DHEA and DHEA-S observed after the administration of DHEA by various routes. Sections of the article specifically address DHEA and DHEA-S concentrations as they relate to stress, central nervous system function and psychiatric disorders, insulin sensitivity, immunological function, and cardiovascular disorders.
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The aim of this study was to characterize and describe the cortisol responses in athletes over a 24-h period on different days involving multiple exercise sessions of varied intensity. Seventeen endurance athletes volunteered to undergo three experimental treatment conditions: (a) a control day involving no exercise; (b) an exercise day with two sessions of high-intensity exercise; and (c) an exercise day with two sessions of moderate-intensity exercise. Significant changes (P < 0.01) were found owing to the influence of both types of exercise during the daytime (high-intensity exercise producing a greater cortisol response than moderate intensity). At night after the moderate-intensity exercise (at selected times), cortisol response was significantly less than during the control condition at corresponding times (P < 0.05). After high-intensity exercise (at selected times), cortisol levels were significantly less (P < 0.05) than in the control condition at corresponding times. Additionally, certain night-time responses after the high-intensity exercise were significantly less than the moderate-intensity exercise responses at similar time points. The results indicate that daytime multiple exercise sessions produce suppressed cortisol levels at night, and the magnitude of this effect is dependent upon the intensity at which the daytime exercise is performed. The physiological mechanism inducing this effect upon cortisol levels at night is unclear from the present data.
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We propose that there is a link between muscle protein synthesis and breakdown that is regulated, in part, through maintenance of the free intracellular pool of essential amino acids. For example, we propose that muscle protein breakdown is paradoxically elevated in the anabolic state following resistance exercise in part because the even greater stimulation of synthesis would otherwise deplete this pool. Thus, factors regulating muscle protein breakdown must be evaluated in the context of the prevailing rate of muscle protein synthesis. Further, the direct effect of factors on breakdown may depend on the physiological state. For example, local hyperinsulinemia suppresses accelerated muscle protein breakdown after exercise, but not normal resting breakdown. Thus, factors regulating muscle protein breakdown in human subjects are complex and interactive.
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This study examined intra-individual change in testosterone, cortisol, and hormone-behavior relationships in response to a rowing ergometer competition. Forty-six members (23 females) of a university crew team provided saliva samples before, 20- and 40-min post-competition, as well as baselines on a non-competition day. Behavioral assessments included measures of previous rowing experience, dominance, competitiveness, bonding with teammates, pre- and post-competition mental state and performance. Men's and women's endocrine responses to this competitive setting were more different than alike and varied by level of competitive experience, the specific phase of the competitive event, and the particular hormone measured. Inter-individual differences in testosterone and cortisol were differentially associated with social affiliation with teammates but rarely with dominance or competitiveness. Theoretically, the findings support the integration of features of the 'tend and befriend' model with the biosocial model of status, and suggest future research directions that may lead to clarification and refinement of those ideas.
Ineffective training, free-radical formation and low protein diet in Polish sportsman
  • A Matuszkiewicz
  • J Kaczor
  • W Ratkowski
  • J Popingis
  • A C Hackney
Matuszkiewicz, A,, Kaczor, J., Ratkowski, W., Popingis, J. and Hackney, A.C. (2001) Ineffective training, free-radical formation and low protein diet in Polish sportsman. Medycyna Sportowa 17, S21.
Endocrine responses to exercise and training
  • R G Mcmurray
  • A C Hackney
McMurray, R.G. and Hackney, A.C. (2000) Endocrine responses to exercise and training. In: Exercise and Sport Science. Eds: Garrett, W.E. and Kirkendall, D.T. Philadelphia: Lippincott Williams & Wilkins. 135-156.