Acute testosterone and cortisol responses to high power resistance exercise

This study examined the acute hormonal responses to a single high power resistance exercise training session. Four weight trained men (X ± SD; age [yrs] = 24.5 ± 2.9; hgt [m] = 1.82 ± 0.05; BW [kg] = 96.9 ± 10.6; 1 RM barbell squat [kg] = 129.3 ± 17.4) participated as subjects in two randomly ordered sessions. During the lifting session, serum samples were collected pre- and 5 min post-exercise, and later analyzed for testosterone (Tes), cortisol (Cort), their ratio (Tes/Cort), and lactate (HLa). The lifting protocol was 10 × 5 speed squats at 70% of system mass (1 RM + BW) with 2 min inter-set rest intervals. Mean power and velocity were determined for each repetition using an external dynamometer. On the control day, the procedures and times (1600–1900 h) were identical except the subjects did not lift. Tes and Cort were analyzed via EIA. Mean ± SD power and velocity was 1377.1 ± 9.6 W and 0.79 ± 0.01 m s⁻¹ respectively for all repetitions, and did not decrease over the 10 sets (p < 0.05). Although not significant, post-exercise Tes exhibited a very large effect size (nmol L⁻¹; pre = 12.5 ± 2.9, post = 20.0 ± 3.9; Cohen’s D = 1.27). No changes were observed for either Cort or the Tes/Cort ratio. HLa significantly increased post-exercise (mmol L⁻¹; pre = 1.00 ± 0.09, post = 4.85 ± 1.10). The exercise protocol resulted in no significant changes in Tes, Cort or the Tes/Cort ratio, although the Cohen’s D value indicates a very large effect size for the Tes response. The acute increase for Tes is in agreement with previous reports that high power activities can elicit a Tes response. High power resistance exercise protocols such as the one used in the present study produce acute increases of Tes. These results indicate that high power resistance exercise can contribute to an anabolic hormonal response with this type of training, and may partially explain the muscle hypertrophy observed in athletes who routinely employ high power resistance exercise.     

Testosterone,cortisol, and human competition

Testosterone and cortisol figure prominently in the research literature having to do with human competition. In this review, we track the history of this literature, concentrating particularly on major theoretical and empirical contributions, and provide commentary on what we see as important unresolved issues. In men and women, athletic competition is typically associated with an increase in testosterone (T) and cortisol (C). Hormone changes in response to non-athletic competition are less predictable. Person (e.g., power motivation, mood, aggressiveness, social anxiety, sex, and baseline levels of T and C) and context (e.g., whether a competition is won or lost, the closeness of the competition, whether the outcome is perceived as being influenced by ability vs. chance, provocations) factors can influence hormone responses to competition. From early on, studies pointed to a positive relationship between T and dominance motivation/status striving. Recent research, however, suggests that this relationship only holds for individuals with low levels of C – this is the core idea of the dual-hormone hypothesis, and it is certain that the broadest applications of the hypothesis have not yet been realized. Individuals differ with respect to the extent to which they embrace competition, but the hormonal correlates of competitiveness remain largely unexplored. Although rapid increases in both T and C associated with competition are likely adaptive, we still know very little about the psychological benefits of these hormonal changes. Administration studies have and will continue to contribute to this inquiry. We close with a discussion of what, we think, are important methodological and mechanistic issues for future research.     

Intensive resistance exercise induces lymphocyte apoptosis via cortisol and glucocorticoid receptor-dependent pathways

Intensive endurance exercise is known to induce lymphocyte apoptosis, which might affect immune function. Less is known about the effects of resistance exercise on apoptosis and its underlying mechanisms. In this study, subjects performed an intensive resistance test (IRT) and a moderate resistance test, and lymphocyte apoptosis, apoptosis-related parameters, and underlying mechanisms were investigated. IRT induced a significant increase of lymphocyte apoptosis 3 h after exercise, which was accompanied by a significant decrease of mitochondrial membrane potential, a reduction of Bcl-2, and an upregulation of the CD95 receptor. Blood lactate, IL-6, C-reactive protein, and cortisol increased significantly 3 h after IRT. A significant correlation was observed between the increase of apoptosis and cortisol levels 3 h after IRT. Incubation of freshly isolated lymphocytes in IRT serum indicated an important role of serum correlates for apoptosis induction. Selective incubation of lymphocytes in concentrations of selected serum parameters corresponding to levels found post in IRT serum demonstrated a major role for cortisol in apoptosis induction. This result was confirmed by attenutation of apoptosis after addition of mifepristone before incubation in IRT serum. In summary, resistance exercise induced lymphocyte apoptosis in an intensity-dependent way. Furthermore, cortisol signaling via glucocorticoid receptors might be an important mechanism for lymphocyte apoptosis after resistance exercise.     

Salivary testosterone and cortisol responses in professional rugby players after four resistance exercise protocols

The acute response of free salivary testosterone (T) and cortisol (C) concentrations to four resistance exercise (RE) protocols in 23 elite men rugby players was investigated. We hypothesized that hormonal responses would differ among individuals after four distinct RE protocols: four sets of 10 repetitions (reps) at 70% of 1 repetition maximum (1RM) with 2 minutes' rest between sets (4 x 10-70%); three sets of five reps at 85% 1RM with 3 minutes' rest (3 x 5-85%); five sets of 15 reps at 55% 1RM with 1 minute's rest (5 x 15-55%); and three sets of five reps at 40% 1RM with 3 minutes' rest (3 x 5-40%). Each athlete completed each of the four RE protocols in a random order on separate days. T and C concentrations were measured before exercise (PRE), immediately after exercise (POST), and 30 minutes post exercise (30 POST). Each protocol consisted of four exercises: bench press, leg press, seated row, and squats. Pooled T data did not change as a result of RE, whereas C declined significantly. Individual athletes differed in their T response to each of the protocols, a difference that was masked when examining the pooled group data. When individual data were retrospectively tabulated according to the protocol in which each athlete showed the highest T response, a significant protocol-dependent T increase for all individuals was revealed. Therefore, RE induced significant individual, protocol-dependent hormonal changes lasting up to 30 minutes after exercise. These individual responses may have important ramifications for modulating adaptation to RE and could explain the variability often observed in studies of hormonal response to RE.     

橘皮素对高强度运动诱发的人体皮质醇应激反应的影响*

目的: 探讨4周橘皮素补充对高强度抗阻运动诱发的皮质醇应激反应的影响。方法: 将24名短跑运动员进行配对,随机分为试验组和对照组。试验组每天补充橘皮素补剂(含橘皮素200 mg),对照组每天补充安慰剂,为期4周。两组运动员均在干预前一日和干预后次日进行抗阻运动激发试验(推举、深蹲、卧推和硬拉,每个动作×4组×10RM)。采集受试者在运动激发试验前即刻(PRE)、试验后即刻(P0)以及第10(P10)、20(P20)和30(P30)分钟时的血液样本,测量血清皮质醇、促肾上腺皮质激素(ACTH)、超氧化物歧化酶(SOD)、白细胞计数(WBC)和血糖,以及PRE和P0时的血乳酸值。结果: 与干预前同期比较,补充橘皮素4周后,试验组在激发试验前PRE的血清皮质醇水平(P=0.017)、激发试验后P10的血清皮质醇水平(P=0.010)、激发试验后P20和激发试验后P30的血清皮质醇水平均显著降低(P＜0.05或 P＜0.01),试验组在激发试验前PRE的WBC、激发试验后P10的ACTH(P=0.037)和激发试验后P30的WBC、ACTH均显著降低(P＜0.05);与对照组比较,试验组在激发试验前PRE和激发试验后P10的血清皮质醇水平显著降低(P＜0.05),激发试验后P30的ACTH和WBC水平显著降低(P＜0.05,P＜0.01)、SOD活性水平显著升高(P＜0.05)。结论: 橘皮素能有效缓解高强度运动诱发的人体皮质醇应激反应,抑制皮质醇过度分泌,提升人体抗氧化能力,加速体内炎症消除,促进身体机能恢复。     

Testosterone, cortisol, and mood in a sports team competition

In humans, hormonal responses to winning/losing and their relationships to mood and status change have mostly been examined in individual athletic competitions. In this study, the salivary testosterone (T) and cortisol (C) and mood responses to a real match between two professional basketball teams were investigated. Data about individuals' contributions to outcome, performance appraisal, and attribution of outcome to internal/external factors were also collected. Results did not show statistically significant different T and C responses depending on the outcome. Negative mood was significantly enhanced, especially in the losers, while winners showed a better appraisal of team performance and a more internal attribution. T response did not show a significant relationship with mood changes, but it correlated positively with the "score/time playing" ratio, an indicator of individual participation in the outcome. Furthermore, T response correlated negatively with external attribution in winners and positively in losers. These results indicate that in a real, highly competitive situation, T changes are not directly a response to the outcome, but rather to the contribution the individual makes to it and to the causes he attributes.     

Plasma adrenocorticotropin and cortisol responses to brief high-intensity exercise in humans

The purpose of this study is to examine plasma cortisol and adrenocorticotropin (ACTH) levels following a brief high-intensity bout of exercise. Each subject (n = 6) performed a 1-min bout of exercise on a cycle ergometer at 120% of his maximum O2 uptake. Blood samples were collected at rest, immediately following the exercise bout, and at 5, 15, and 30 min postexercise. Mean (+/- SE) plasma ACTH levels increased significantly (P less than 0.05) from 2.2 +/- 0.4 pmol/l at rest to 6.2 +/- 1.7 pmol/l immediately following exercise. Mean (+/- SE) plasma cortisol levels increased significantly from 0.40 +/- 0.04 mumol/l at rest to 0.52 +/- 0.04 mumol/l at 15 min postexercise. These data show that brief high-intensity exercise results in significant increases in plasma cortisol and ACTH levels. Furthermore, the temporal sequence between the two hormones suggests that the increase in plasma cortisol levels following brief high-intensity exercise is the result of ACTH-induced steroidogenesis in the adrenal cortex.     

Roots,nutrients and their relationship to spatial patterns

Ecosystem sustainability and resilience after a disturbance may be regulated by processes occurring at smaller spatial scales. The matrix of different spatial environments are created by (1) individual plants that accumulate higher concentrations of specific nutrients, trace elements or defensive plant secondary chemicals and thereby modify the chemistry of their ecological space and/or rates of processes, (2) the presence of structures (e.g., coarse woody debris) that may buffer some micro-environments from disturbances by functioning as a hospitable environment or as a reservoir for mycorrhizal fungi to sustain them into the next phase of stand development, and (3) chemical changes in soils during soil development which may result in distinct soil chemical environments. The response of the plants or change in the sustainability of carbon and nutrient cycles may be expressed more strongly at this smaller ecological space of an individual plant and furthermore must be frequently examined separately by the above- and belowground space of that individual.This paper will present three case studies from temperate and tropical forest ecosystems which suggest the importance of studying plant growth and nutrient and trace element cycling by stratifying sampling to encompass the mosaic patterns of existing spatial variability within the ecosystem. The examples show how individual plant species are able to create ecologically distinct spatial environments because of their distribution patterns within the landscape, how nutrient transfers in roots respond to the chemical variations in the soil, and how roots and mycorrhizal fungi are able to maintain themselves in the mosaic of coarse woody debris remaining on a site after the elimination of aboveground tree biomass.     

Glucocorticoid response to exercise as measured by serum and salivary cortisol

Serum and salivary cortisol concentrations were studied in 78 elite athletes engaged in different sports, by subjecting them to high-intensity laboratory exercise. The mean difference in the pre-exercise cortisol concentrations in the seven groups studied were more marked in serum (from 311 to 768 nmol.l-1) than in saliva (from 17.9 to 22.7 nmol.l-1, only one group reaching 40 nmol.l-1). Judging from the correlation coefficients based on total variances, the post-/pre-exercise differences in cortisol concentrations in serum depended chiefly on pre-exercise values, while those in saliva tended to depend more on the postexercise concentrations. The coefficients of correlation between that difference and either the pre- or postexercise values were -0.71 and 0.47, respectively, for serum, and -0.51 and 0.58, respectively, for saliva. This would suggest that salivary cortisol concentration might be a more suitable variable for assessing glucocorticoid activity in exercise than serum cortisol concentration, probably being less sensitive to pre-exercise emotional state.     

Testosterone and cortisol concentrations vary with reproductive status in wild female red deer

Although hormones are key regulators of many fitness and life history traits, the causes of individual level variation in hormones, particularly in wild systems, remain understudied. Whilst we know that androgen and glucocorticoid levels vary within and among individuals in mammalian populations, how this relates to key reproductive processes such as gestation and lactation, and their effects on a female''s measurable hormone levels are poorly understood in wild systems. Using fecal samples collected from females in a wild red deer population between 2001 and 2013, we explore how fecal androgen (FAM) and cortisol (FCM) metabolite concentrations change with age and season, and how individual differences relate to variation in reproductive state. Both FAM and FCM levels increase toward parturition, although this only affects FCM levels in older females. FCM levels are also higher when females suckle a male rather than a female calf, possibly due to the higher energetic costs of raising a son. This illustrates the importance of accounting for a female''s life history and current reproductive status, as well as temporal variation, when examining individual differences in hormone levels. We discuss these findings in relation to other studies of mammalian systems and in particular to the relatively scarce information on variation in natural levels of hormones in wild populations.     

Gut microbiota bridges dietary nutrients and host immunity

Dietary nutrients and the gut microbiota are increasingly recognized to cross-regulate and entrain each other, and thus affect host health and immune-mediated diseases. Here, we systematically review the current understanding linking dietary nutrients to gut microbiota-host immune interactions, emphasizing how this axis might influence host immunity in health and diseases. Of relevance, we highlight that the implications of gut microbiota-targeted dietary intervention could be harnessed in orche...     

Testosterone and cortisol jointly regulate dominance: Evidence for a dual-hormone hypothesis

Traditional theories propose that testosterone should increase dominance and other status-seeking behaviors, but empirical support has been inconsistent. The present research tested the hypothesis that testosterone's effect on dominance depends on cortisol, a glucocorticoid hormone implicated in psychological stress and social avoidance. In the domains of leadership (Study 1, mixed-sex sample) and competition (Study 2, male-only sample), testosterone was positively related to dominance, but only in individuals with low cortisol. In individuals with high cortisol, the relation between testosterone and dominance was blocked (Study 1) or reversed (Study 2). Study 2 further showed that these hormonal effects on dominance were especially likely to occur after social threat (social defeat). The present studies provide the first empirical support for the claim that the neuroendocrine reproductive (HPG) and stress (HPA) axes interact to regulate dominance. Because dominance is related to gaining and maintaining high status positions in social hierarchies, the findings suggest that only when cortisol is low should higher testosterone encourage higher status. When cortisol is high, higher testosterone may actually decrease dominance and in turn motivate lower status.     

The effects of mouthpiece use on cortisol levels during an intense bout of resistance exercise

Research has suggested mouthpiece use during exercise results in an increase in muscle strength and endurance. However, the research is difficult to replicate, and the methodology suggested measures that were too subjective to determine a mouthpiece effect. Thus, the purpose of this study was to use an objective measure to determine a possible physiological mechanism occurring during and after exercise with mouthpiece use. A within-subjects design was used in which 28 division I football players, aged 18-22 years, performed 2 identical bouts of a 1-hour intense resistance exercise, with each subject being randomly assigned the use of a custom-fit mouthpiece either during the first or second session. During both exercise sessions, saliva was analyzed for cortisol at the following time points: pre-exercise, 25, 45, and 60 minutes of exercise, and 10 minutes postexercise. The results revealed a significant difference in cortisol levels with the use of a mouthpiece vs. no mouthpiece (p = 0.019) at 10 minutes postexercise. Additionally, although the expected increase in cortisol levels from pre to 10 minutes postexercise was present in the no-mouthpiece group (p = 0.01), no such increase was observed in the mouthpiece group. These observations are most likely because of the decrease in cortisol from post to 10 minutes post (p = 0.04) in the mouthpiece group. These data demonstrate that although cortisol continued to increase in the no-mouthpiece session, there was a significant decrease in cortisol in the no-mouthpiece condition 10 minutes postexercise.     

Testosterone and cortisol jointly regulate dominance: Evidence for a dual-hormone hypothesis

Traditional theories propose that testosterone should increase dominance and other status-seeking behaviors, but empirical support has been inconsistent. The present research tested the hypothesis that testosterone's effect on dominance depends on cortisol, a glucocorticoid hormone implicated in psychological stress and social avoidance. In the domains of leadership (Study 1, mixed-sex sample) and competition (Study 2, male-only sample), testosterone was positively related to dominance, but only in individuals with low cortisol. In individuals with high cortisol, the relation between testosterone and dominance was blocked (Study 1) or reversed (Study 2). Study 2 further showed that these hormonal effects on dominance were especially likely to occur after social threat (social defeat). The present studies provide the first empirical support for the claim that the neuroendocrine reproductive (HPG) and stress (HPA) axes interact to regulate dominance. Because dominance is related to gaining and maintaining high status positions in social hierarchies, the findings suggest that only when cortisol is low should higher testosterone encourage higher status. When cortisol is high, higher testosterone may actually decrease dominance and in turn motivate lower status.     

Hormonal underpinnings of status conflict: Testosterone and cortisol are related to decisions and satisfaction in the hawk-dove game

A contribution to a special issue on Hormones and Human Competition.Testosterone is theorized to influence status-seeking behaviors such as social dominance and competitive behavior, but supporting evidence is mixed. The present study tested the roles of testosterone and cortisol in the hawk-dove game, a dyadic economic decision-making paradigm in which earnings depend on one's own and the other player's choices. If one person selects the hawk strategy and the other person selects the dove strategy, the player who selected hawk attains a greater financial pay-off (status differentiation). The worst financial outcome occurs when both players choose the hawk strategy (status confrontation). Ninety-eight undergraduate students (42 men) provided saliva samples and played ten rounds of the hawk-dove game with another same-sex participant. In support of the hypothesis that testosterone is related to status concern, individuals higher in basal testosterone made more hawk decisions — decisions that harmed the other player. Acute decreases in cortisol were also associated with more hawk decisions. There was some empirical support for the dual-hormone hypothesis as well: basal testosterone was positively related to satisfaction in the game among low basal-cortisol individuals but not among high basal-cortisol individuals. There were no significant sex differences in these hormonal effects. The present findings align with theories of hormones and status-seeking behavior at the individual level, but they also open up new avenues for research on hormone profiles at the collective level. Our results suggest that the presence of two or more high-testosterone members increases the likelihood of status confrontations over a limited resource that can undermine collective outcomes.     

Muscular adaptations to resistance exercise in the elderly

Neuropathic, metabolic, hormonal, nutritional and immunological factors contribute to the development of sarcopenia. This loss of muscle mass associated with ageing, is a main cause of muscle weakness, but the loss of muscle strength typically exceeds that of muscle size, with a resulting decrease in force per unit of muscle cross-sectional area. Recent evidence suggests that, in addition to a reduction in neural drive and in fibre specific tension, changes in muscle architecture contribute significantly to the loss of muscle force through alterations in muscle mechanical properties. Older muscle, however, maintains a high degree of plasticity in response to increased loading since considerable hypertrophy and a reversal of the alterations in muscle architecture associated with ageing are observed with resistive training.     

Twenty-four-hour metabolic responses to resistance exercise in women

Seven nonobese adult females (40 +/- 8 years) were studied in a room calorimeter on a day that resistance exercise (REX) was performed (4 sets of 10 exercises) and on a nonexercise control day (CON). Twenty-four-hour energy expenditure (EE) on the REX day (mean +/- SD, 2,328 +/- 327 kcal.d(-1)) was greater than CON (2,001 +/- 369 kcal.d(-1), p < 0.001). The net increase in EE during and immediately after (30 minutes) exercise represented 76 +/- 12% of the total increase in 24-hour EE. Twenty four-hour RQ on the REX day (0.86 +/- 0.06) did not differ from CON (0.87 +/- 0.02). Twenty four-hour carbohydrate oxidation was elevated on the REX day, but 24-hour fat and protein oxidation were not different. Thus, in women, the increase in EE due to resistance exercise is largely seen during and immediately after the exercise. The increased energy demand is met by increased carbohydrate oxidation, with no increase in 24-hour fat oxidation.