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Casto KV, Cohen DJ, Akinola M, Mehta PH. Testosterone, gender identity and gender-stereotyped personality attributes. Horm Behav 2024; 162:105540. [PMID: 38652981 DOI: 10.1016/j.yhbeh.2024.105540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 03/29/2024] [Accepted: 03/29/2024] [Indexed: 04/25/2024]
Abstract
Sex/gender differences in personality associated with gender stereotyped behavior are widely studied in psychology yet remain a subject of ongoing debate. Exposure to testosterone during developmental periods is considered to be a primary mediator of many sex/gender differences in behavior. Extensions of this research has led to both lay beliefs and initial research about individual differences in basal testosterone in adulthood relating to "masculine" personality. In this study, we explored the relationships between testosterone, gender identity, and gender stereotyped personality attributes in a sample of over 400 university students (65 % female assigned at birth). Participants provided ratings of their self-perceived masculinity and femininity, resulting in a continuous measure of gender identity, and a set of agentic and communal personality attributes. A saliva sample was also provided for assay of basal testosterone. Results showed no compelling evidence that basal testosterone correlates with gender-stereotyped personality attributes or explains the relationship between sex/gender identity and these attributes, across, within, or covarying out sex assigned at birth. Contributing to a more gender diverse approach to assessing sex/gender relationships with personality and testosterone, our continuous measure of self-perceived masculinity and femininity predicted additional variance in personality beyond binary sex and showed some preliminary but weak relationships with testosterone. Results from this study cast doubt on the activational testosterone-masculinity hypothesis for explaining sex differences in gender stereotyped traits and within-sex/gender variation in attributes associated with agency and communality.
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Affiliation(s)
- Kathleen V Casto
- Kent State University, Department of Psychological Sciences, United States of America.
| | - Dale J Cohen
- University of North Carolina Wilmington, Department of Psychology, United States of America
| | - Modupe Akinola
- Columbia University, Columbia Business School, United States of America
| | - Pranjal H Mehta
- University College London, Department of Experimental Psychology, United Kingdom of Great Britain and Northern Ireland
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Grainger A, Comfort P, Twist C, Heffernan SM, Tarantino G. Real-World Fatigue Testing in Professional Rugby Union: A Systematic Review and Meta-analysis. Sports Med 2024; 54:855-874. [PMID: 38114782 DOI: 10.1007/s40279-023-01973-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/12/2023] [Indexed: 12/21/2023]
Abstract
BACKGROUND Professional rugby union is a high-intensity contact sport with position-specific high training and match volumes across a season that may lead to periods of fatigue if above a typically experienced threshold. This study assesses the influence of match play and/or training on fatigue levels in rugby union players. OBJECTIVE We aimed to perform a systematic review and meta-analysis of measures used to assess fatigue status in male professional rugby union players. METHODS Using electronic databases (PubMed, SPORTDiscus, Web of Science, Cochrane Library, EMBASE, and MEDLINE), a systematic review of fatigue testing in rugby union was conducted on (1) neuromuscular, (2) subjective self-report, (3) biochemical, and (4) heart rate-derived measures. RESULTS Thirty-seven articles were included in this systematic review, of which 14 were further included in a meta-analysis. The results of the meta-analysis revealed small, yet not significant, decreases in countermovement jump height immediately after (effect size [ES] = - 0.29; 95% confidence interval [CI] - 0.64 to 0.06), 24 h (ES = - 0.43; 95% CI - 3.99 to 3.21), and 48 h (ES = - 0.22; 95% CI - 0.47 to 0.02) after exposure to rugby union match play or training. Reported wellness (ES = - 0.33; 95% CI - 1.70 to 1.04) and tiredness (ES = - 0.14; 95% CI - 1.30 to 1.03) declined over a period of a few weeks (however, the results were not-statistically significant), meanwhile muscle soreness increased (ES = 0.91; 95% CI 0.06 to 1.75) within the 96 h after the exposure to rugby union match play or training. Finally, while cortisol levels (ES = 1.87; 95% CI - 1.54 to 5.29) increased, testosterone declined (ES = - 1.54; 95% CI - 7.16 to 4.08) within the 24 h after the exposure. However, these results were not statistically significant. CONCLUSIONS Subjective measures of muscle soreness can be used to assess fatigue after match play and training in rugby union players. Within-study and between-study variability for countermovement jump height, biochemical markers, and heart rate-derived measures means the utility (practical application) of these measures to assess fatigue in professional rugby union players after matches and training is unclear. CLINICAL TRIAL REGISTRATION PROSPERO ID: CRD42020216706.
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Affiliation(s)
- Adam Grainger
- Kitman Labs, Dublin, Ireland.
- Institute of Sport and Health, University College Dublin, Dublin, Ireland.
| | - Paul Comfort
- University of Salford, Salford, Greater Manchester, UK
- Edith Cowan University, Joondalup, WA, Australia
| | - Craig Twist
- Research Institute of Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
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Hu X, Baba NT, Philippe K, Jiang D, Boisbluche S, Maurelli O, Prioux J. Effects of preseason training on body composition, running performance, biochemical markers and workload variation in professional rugby union players. Heliyon 2023; 9:e16250. [PMID: 37265613 PMCID: PMC10230214 DOI: 10.1016/j.heliyon.2023.e16250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Revised: 05/02/2023] [Accepted: 05/10/2023] [Indexed: 06/03/2023] Open
Abstract
Few studies have examined the impact of a preseason training intervention through systematic measures in Pro D2 rugby union (RU). Therefore, this study aimed to describe the effects of 12 weeks of preseason training (three blocks) on body composition, running performance, biochemical markers, and workload (WL) variation in professional RU players. Physiological (physical and biochemical) responses to preseason WL were analyzed by examining changes in anthropometric characteristics, Yo-Yo intermittent recovery level 1 (Yo-Yo IR1) test, blood samples (BS), Hooper index (1-7), the 10-Hz global positioning system (GPS), and session rating of perceived exertion (s-RPE) in nineteen elite male players. Changes throughout the preseason were analyzed using the one-way and mixed-model analysis of variance. Significant (p < 0.01) improvements occurred in anthropometry and Yo-Yo IR1 running performance in forwards and backs. Total distance (p < 0.01) and impact (p < 0.05) during the second block were meaningfully higher than the other two blocks, with backs showing higher values than forwards. As expected, WL decreased significantly (p < 0.01) during the last training block. The WL variations were correlated with changes in biochemical markers over the preseason period. The collected data can be used for i) profiling French Pro D2 rugby championships players, ii) establishing effective training strategies, and iii) setting preseason WL expectations.
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Affiliation(s)
- Xiaopan Hu
- Sino-French Joint Research Center of Sport Science, Key Laboratory of Adolescent Health Assessment and Exercise Intervention of Ministry of Education, College of Physical Education and Health, East China Normal University, 200241 Shanghai, China
- Movement, Sport, Health Laboratory, Rennes 2 University, 35170 Bruz, France
- Department of Sports Sciences and Physical Education, École Normale Supérieure de Rennes, 35170 Bruz, France
| | - Noe Thierry Baba
- Department of Physical Education and Sport Science, University of Limerick, V94 XD21 Limerick, Ireland
| | - Kilian Philippe
- Movement, Sport, Health Laboratory, Rennes 2 University, 35170 Bruz, France
- Department of Sports Sciences and Physical Education, École Normale Supérieure de Rennes, 35170 Bruz, France
- Laboratory of Movement, Balance, Performance and Health, University of Pau and Pays de l’Adour, 65000 Tarbes, France
| | - Danyang Jiang
- Ersha Sports Training Center of Guangdong Province, 510105 Guangdong, China
| | - Simon Boisbluche
- Rugby Club Vannes, French Rugby Federation, 56000 Vannes, France
| | - Olivier Maurelli
- Muscle Dynamics and Metabolism Laboratory, University of Montpellier, 34060 Montpellier, France
| | - Jacques Prioux
- Sino-French Joint Research Center of Sport Science, Key Laboratory of Adolescent Health Assessment and Exercise Intervention of Ministry of Education, College of Physical Education and Health, East China Normal University, 200241 Shanghai, China
- Movement, Sport, Health Laboratory, Rennes 2 University, 35170 Bruz, France
- Department of Sports Sciences and Physical Education, École Normale Supérieure de Rennes, 35170 Bruz, France
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Crewther BT, Hecht M, Grillot RL, Eisenbruch AB, Catena T, Potts N, Kilduff LP, Cook CJ, Maestripieri D, Roney JR. Day-to-day coordination of the stress and reproductive axes: A continuous-time analysis of within-person testosterone and cortisol relationships in athletic and healthy men. Physiol Behav 2023; 263:114104. [PMID: 36731761 DOI: 10.1016/j.physbeh.2023.114104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 01/20/2023] [Accepted: 01/28/2023] [Indexed: 02/02/2023]
Abstract
Day-to-day coordination of the stress (i.e., hypothalamic-pituitary-adrenal [HPA]) and reproductive (i.e., hypothalamic-pituitary-gonadal [HPG]) axes is central to allostatic regulation, reproductive success, and survival. Reports of positive, within-person testosterone and cortisol relationships (or coupling) suggest cross-talk of a facilitative nature, but longitudinal evidence is scarce and has methodological and analytical limitations. To address this, we used a continuous-time (CT) model to investigate day-to-day, within-person coupling of testosterone and cortisol in two male cohorts. Salivary testosterone and cortisol fluctuations were monitored in 35 athletic men across two international tournaments (M = 19.3 tests) and in 41 healthy men during normal daily living (M = 27.9 tests). Bayesian CT analysis revealed a diminishing effect of each hormone on itself as time-interval length or lag increased. In both groups, cortisol had a negative lagged effect on testosterone that persisted for around three days. The cortisol effect on testosterone peaked after 0.71 and 0.51 days in athletic (standardized estimate = -0.13) and healthy men (standardized estimate = -0.11), respectively. Further estimates of non-lagged, contemporaneous correlations revealed positive testosterone and cortisol relationships (athlete r = 0.04, healthy r = 0.46). In summary, complex within-person HPA and HPG interplay emerged in two independent male cohorts. Specifically, a rising cortisol concentration was linked to a fall in testosterone concentration at later time points, but concurrently these hormones tended to rise and fall together. Our results suggest that inhibitory and facilitatory hormonal actions coexist on varying timescales, thereby expanding knowledge of HPG and HPA cross-talk in everyday life.
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Affiliation(s)
- Blair T Crewther
- Institute of Sport - National Research Institute, Warsaw, Poland; School of Science and Technology, University of New England, Armidale, Australia; Hamlyn Centre, Imperial College, London, UK.
| | | | - Rachel L Grillot
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, USA
| | | | - Tikal Catena
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, USA
| | - Neill Potts
- Western Australian Institute of Sport, Perth, Australia
| | - Liam P Kilduff
- A-STEM, Faculty of Science and Engineering, Swansea University, Swansea, UK; Welsh Institute of Performance Science (WIPS), Swansea University, Swansea, UK
| | - Christian J Cook
- School of Science and Technology, University of New England, Armidale, Australia; Hamlyn Centre, Imperial College, London, UK
| | | | - James R Roney
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, USA
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Casto KV, Prasad S, Josephs RA, Zilioli S, Welker K, Maslov A, Jones AC, Mehta PH. No Compelling Evidence that Self-Reported Personality Traits Explain Basal Testosterone and Cortisol’s Associations with Status-Relevant Behavior. ADAPTIVE HUMAN BEHAVIOR AND PHYSIOLOGY 2023. [DOI: 10.1007/s40750-023-00210-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/28/2023]
Abstract
Abstract
Objective
A goal of behavioral neuroendocrinology is to understand how basal hormone levels relate to behavior. Studies of human participants sometimes measure self-reported personality traits, in addition to or instead of direct behavioral observation. Although personality traits often predict their respective behaviors, whether personality explains hormone-behavior relationships remains unclear.
Methods
We obtained data from eight previous studies (total N = 985) that examined baseline testosterone and cortisol as predictors of status-relevant behavior (competitiveness, dominance, risk-taking, aggression, affiliation, and social status). We tested whether the previously reported hormone-behavior relationships are mediated by self-reported personality traits (e.g., trait dominance, prestige, extraversion). As a secondary research question, we also tested whether trait dominance moderated the testosterone-behavior relationships.
Results
As expected, self-reported personality traits often predicted status-relevant behaviors, but there was little evidence that traits also correlated with basal testosterone or the testosterone × cortisol interaction. Across all eight studies, personality traits did not significantly mediate hormone-behavior relationships. Indeed, the effect sizes of the hormone-behavior relationships were robust to the inclusion of personality traits as covariates. Further, we did not find strong or consistent evidence that trait dominance moderates the testosterone-behavior association.
Conclusion
Results suggest that basal testosterone and cortisol predict status-related behavior independent of self-reported personality. We discuss how these results may have broader implications for the physiological mechanisms by which testosterone and cortisol influence behavior, a process that could be unconscious and automatic. We also discuss alternative explanations, limitations, and future directions.
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Casto KV, Arthur LC, Hamilton DK, Edwards DA. Testosterone, Athletic Context, Oral Contraceptive Use, and Competitive Persistence in Women. ADAPTIVE HUMAN BEHAVIOR AND PHYSIOLOGY 2021. [DOI: 10.1007/s40750-021-00180-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Casto KV, Edwards DA. Individual differences in hormonal responsiveness to social encounters: Commentary on Félix et al., 2020 and review of pertinent issues. Horm Behav 2021; 129:104921. [PMID: 33428922 DOI: 10.1016/j.yhbeh.2020.104921] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 12/28/2020] [Accepted: 12/30/2020] [Indexed: 01/22/2023]
Abstract
The results of a recent study, Félix et al., 2020, give new information about the behavioral and endocrine correlates of individual differences in the potential for androgen response in male cichlid fish. We think the study raises issues that are pertinent to the study of hormones and competition in other species, particularly humans. Focusing mostly on androgen reactivity to social challenge, we emphasize the importance of inter-individual variability in physiology, personality, and motivation in studies of hormone responses to social encounters. Additionally, we give special attention to matters of "repeatability" and the timing of hormone sampling. We conclude with an appreciation of the value of comparative analysis in behavioral endocrinology.
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Crewther BT, Hecht M, Cook CJ. Diurnal Within-Person Coupling Between Testosterone and Cortisol in Healthy Men: Evidence of Positive and Bidirectional Time-Lagged Associations Using a Continuous-Time Model. ADAPTIVE HUMAN BEHAVIOR AND PHYSIOLOGY 2021. [DOI: 10.1007/s40750-021-00162-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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