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Love AC, Tabb V, Youssef NH, Wilder SM, DuRant SE. Effect of dietary macronutrients and immune challenge on gut microbiota, physiology and feeding behaviour in zebra finches. Mol Ecol 2024:e17428. [PMID: 38837812 DOI: 10.1111/mec.17428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 05/02/2024] [Accepted: 05/16/2024] [Indexed: 06/07/2024]
Abstract
Macronutrients play a vital role in host immunity and can influence host-pathogen dynamics, potentially through dietary effects on gut microbiota. To increase our understanding of how dietary macronutrients affect physiology and gut microbiota and investigate whether feeding behaviour is influenced by an immune threat, we conducted two experiments. First, we determined whether zebra finches (Taeniopygia guttata) exhibit shifts in physiology and gut microbiota when fed diets differing in macronutrient ratios. We found the type and amount of diet consumed affected gut microbiota alpha diversity, where microbial richness and Shannon diversity increased with caloric intake in birds fed a high-fat diet and decreased with caloric intake in birds fed a high protein diet. Diet macronutrient content did not affect physiological metrics, but lower caloric intake was associated with higher complement activity. In our second experiment, we simulated an infection in birds using the bacterial endotoxin lipopolysaccharide (LPS) and quantified feeding behaviour in immune challenged and control individuals, as well as birds housed near either a control pair (no immune threat), or birds housed near a pair given an immune challenge with LPS (social cue of heightened infection risk). We also examined whether social cues of infection alter physiological responses relevant to responding to an immune threat, an effect that could be mediated through shifts in feeding behaviour. LPS induced a reduction in caloric intake driven by a decrease in protein, but not fat consumption. No evidence was found for socially induced shifts in feeding behaviour, physiology or gut microbiota. Our findings carry implications for host health, as sickness-induced anorexia and diet-induced shifts in the microbiome could shape host-pathogen interactions.
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Affiliation(s)
- Ashley C Love
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, Connecticut, USA
- Department of Integrative Biology, Oklahoma State University, Stillwater, Oklahoma, USA
- Department of Biological Sciences, University of Arkansas, Fayetteville, Arkansas, USA
| | - Victoria Tabb
- Department of Integrative Biology, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Noha H Youssef
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Shawn M Wilder
- Department of Integrative Biology, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Sarah E DuRant
- Department of Biological Sciences, University of Arkansas, Fayetteville, Arkansas, USA
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2
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Corsetti V, Notari T, Montano L. Effects of the low-carb organic Mediterranean diet on testosterone levels and sperm DNA fragmentation. Curr Res Food Sci 2023; 7:100636. [PMID: 38045510 PMCID: PMC10689274 DOI: 10.1016/j.crfs.2023.100636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 11/06/2023] [Accepted: 11/07/2023] [Indexed: 12/05/2023] Open
Abstract
The causes of male infertility can vary. Lifestyles, environmental factors, stressful conditions, and socio-economic conditions are significant factors. Diet plays a crucial role in improving a man's reproductive capacity. The appropriate diet should be diverse and ensure the intake of all the necessary nutrients to enhance sperm quality. The Mediterranean diet, which includes high amounts of vegetables and fruits rich in detoxifying and antioxidant substances, as well as polyphenols, flavonoids, carotenoids, and microelements, especially when consumed with organic foods and a lower carbohydrate regimen, are the key aspects addressed in this study. The objective of this research was to modify the diets of 50 subfertile men by providing them with a specific nutritional plan. This plan included consuming 80% organic foods, introducing whole grains and low glycemic load options, eliminating refined carbohydrates, consuming green leafy vegetables and red fruits daily, reducing or eliminating dairy products, consuming primarily grass-fed meat and wild caught seafood, eliminating saturated fats in favor of healthy fats like olive oil, avocado, and nuts. After three months of adhering to the low-carb food plan, testosterone levels significantly increased, while sperm DNA fragmentation decreased in a subgroup of individuals who reduced their carbohydrate intake by 35%.
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Affiliation(s)
- Veronica Corsetti
- Institute of Translational Pharmacology (IFT)-CNR, Via Fosso del Cavaliere 100, 00133, Rome, Italy
| | - Tiziana Notari
- Check Up -Polydiagnostic and Research Laboratory, Andrology Unit, Viale Andrea De Luca 5/c, 84131, Salerno, Italy
| | - Luigi Montano
- Andrology Unit and Service of Lifestyle Medicine in UroAndrology, Local Health Authority (ASL) Salerno, Coordination Unit of the Network for Environmental and Reproductive Health (Eco-Food Fertility Project), “S. Francesco di Assisi Hospital”, 84020, Oliveto Citra, SA, Italy
- PhD Program in Evolutionary Biology and Ecology, University of Rome “Tor Vergata”, 00133, Rome, Italy
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3
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Gomes GK, de Branco FMS, Santos HO, Pereira JL, Orsatti FL, de Oliveira EP. Cholesterol intake and serum total cholesterol levels are not associated with total testosterone levels in men: a cross-sectional study from NHANES 2013-2014. Lipids Health Dis 2023; 22:168. [PMID: 37798611 PMCID: PMC10552423 DOI: 10.1186/s12944-023-01928-7] [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: 05/21/2023] [Accepted: 09/15/2023] [Indexed: 10/07/2023] Open
Abstract
BACKGROUND Testosterone (T) is an anabolic hormone crucial to the structure and function of skeletal muscle. Testosterone is partially synthesized from cholesterol, but little is known about the relationship of cholesterol intake and serum cholesterol with T levels. AIM To investigate whether cholesterol intake and serum total cholesterol (TC) levels are associated with serum total testosterone (TT) levels in men. METHODS A cross-sectional study enrolling 1996 men aged 20 to 80 years from National Health and Nutrition Examination Survey (NHANES) 2013-2014 was carried out. Diet assessment was performed using two 24-h food recalls, and TT levels were measured by liquid chromatography coupled with tandem mass spectrometry. Regression analyses were performed to evaluate whether TT was associated with cholesterol intake and serum TC levels. RESULTS Neither cholesterol intake nor serum TC levels were associated with TT levels in unadjusted and adjusted analyses (adjustment for energy, total fat and alcohol intake, smoking, age, physical activity, family income, marital status, race, educational level, diabetes, hypertension, and body mass index). CONCLUSION Dietary cholesterol intake and TC levels are not associated with TT levels in men from the USA.
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Affiliation(s)
- Gederson K Gomes
- Laboratory of Nutrition, Exercise and Health (LaNES), School of Medicine, Federal University of Uberlandia (UFU), Uberlandia, Minas Gerais, 38400902, Brazil
| | - Flávia M S de Branco
- Laboratory of Nutrition, Exercise and Health (LaNES), School of Medicine, Federal University of Uberlandia (UFU), Uberlandia, Minas Gerais, 38400902, Brazil
| | - Heitor O Santos
- Laboratory of Nutrition, Exercise and Health (LaNES), School of Medicine, Federal University of Uberlandia (UFU), Uberlandia, Minas Gerais, 38400902, Brazil
| | - Jaqueline L Pereira
- Department of Nutrition, School of Public Health, University of São Paulo (USP), São Paulo - SP, Brazil
| | - Fábio L Orsatti
- Exercise Biology Research Group (BioEx), Federal University of Triangulo Mineiro (UFTM), Uberaba, MG, Brazil
- Department of Sport Sciences, Federal University of Triangulo Mineiro, Uberaba, MG, Brazil
| | - Erick P de Oliveira
- Laboratory of Nutrition, Exercise and Health (LaNES), School of Medicine, Federal University of Uberlandia (UFU), Uberlandia, Minas Gerais, 38400902, Brazil.
- School of Medicine, Federal University of Uberlandia (UFU), Uberlandia, Minas Gerais, Brazil.
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4
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West S, Monteyne AJ, van der Heijden I, Stephens FB, Wall BT. Nutritional Considerations for the Vegan Athlete. Adv Nutr 2023; 14:774-795. [PMID: 37127187 PMCID: PMC10334161 DOI: 10.1016/j.advnut.2023.04.012] [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: 02/22/2023] [Revised: 04/19/2023] [Accepted: 04/27/2023] [Indexed: 05/03/2023] Open
Abstract
Accepting a continued rise in the prevalence of vegan-type diets in the general population is also likely to occur in athletic populations, it is of importance to assess the potential impact on athletic performance, adaptation, and recovery. Nutritional consideration for the athlete requires optimization of energy, macronutrient, and micronutrient intakes, and potentially the judicious selection of dietary supplements, all specified to meet the individual athlete's training and performance goals. The purpose of this review is to assess whether adopting a vegan diet is likely to impinge on such optimal nutrition and, where so, consider evidence based yet practical and pragmatic nutritional recommendations. Current evidence does not support that a vegan-type diet will enhance performance, adaptation, or recovery in athletes, but equally suggests that an athlete can follow a (more) vegan diet without detriment. A clear caveat, however, is that vegan diets consumed spontaneously may induce suboptimal intakes of key nutrients, most notably quantity and/or quality of dietary protein and specific micronutrients (eg, iron, calcium, vitamin B12, and vitamin D). As such, optimal vegan sports nutrition requires (more) careful consideration, evaluation, and planning. Individual/seasonal goals, training modalities, athlete type, and sensory/cultural/ethical preferences, among other factors, should all be considered when planning and adopting a vegan diet.
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Affiliation(s)
- Sam West
- Public Health and Sport Sciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, United Kingdom
| | - Alistair J Monteyne
- Public Health and Sport Sciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, United Kingdom
| | - Ino van der Heijden
- Public Health and Sport Sciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, United Kingdom
| | - Francis B Stephens
- Public Health and Sport Sciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, United Kingdom
| | - Benjamin T Wall
- Public Health and Sport Sciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, United Kingdom.
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5
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Kumar S, Voracek M. Effects of caste, birth season, and family income on digit ratios. Am J Hum Biol 2022; 35:e23852. [PMID: 36524699 DOI: 10.1002/ajhb.23852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 12/05/2022] [Accepted: 12/06/2022] [Indexed: 12/23/2022] Open
Abstract
OBJECTIVES The contributions of latitude and ethnicity in the determination of cross-society differences in digit ratios are unclear. In India, different castes (endogamous groups) have been living in the same areas (villages or towns) for the last 1500 years and, therefore, these groups may have different gene pools without a latitude-related difference component. Thus, in the present study, we studied the effect of caste on digit ratios. We also studied the effects of sex, birth season, and family income on digit ratios. METHODS We selected a sample of 301 college students (age: M = 19.9 years, SD = 2.63) in Muzaffarnagar city of western Uttar Pradesh, India, and asked participants for information regarding their birth month, religion, caste, and monthly family income. We measured participants' dorsal and palmar digit lengths (of all fingers, except the thumb, in both hands) using vernier calipers of 0.01 mm accuracy. RESULTS Other backward castes (intermediate castes) had longer digit lengths than general castes (upper castes), scheduled castes (lower castes), and Muslims. However, there was no difference in digit ratios of caste groups (scheduled castes vs. other backward castes vs. general castes vs. Muslims) or specific castes (Chamar-Jatav vs. Jat vs. Pandit-Tyagi). Winter-born women had lower left dorsal 2D:4D and 3D:4D ratios than summer-born women. Family income was related to higher dorsal 2D:4D and 3D:4D ratios among women. Moreover, in dorsal digit ratios, sex difference (men < women) occurred in digit ratios constituting digit 5, whereas, in palmar digit ratios, sex difference occurred in digit ratios constituting digit 2. CONCLUSIONS The present study suggests that endogamy-led genetic difference in ethnic/caste groups is not a determinant, whereas birth season (i.e., the exposure to sunlight) and family income might be determinants of digit ratios. In addition, compared to palmar digit ratios, dorsal digit ratios are better markers of sexual dimorphism.
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Affiliation(s)
- Sanjay Kumar
- Department of Psychology D.A.V. College Muzaffarnagar Uttar Pradesh India
| | - Martin Voracek
- Department of Cognition, Emotion, and Methods in Psychology, Faculty of Psychology University of Vienna Vienna Austria
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Abstract
A recent meta-analysis found low-carbohydrate, high-protein diets (> 3.4 g/kg of bodyweight/day) (g/kg/day) decreased men's total testosterone (∼5.23 nmol/L) [Whittaker and Harris (2022) Low-carbohydrate diets and men's cortisol and testosterone: systematic review and meta-analysis. Nutrition and Health. DOI: 10.1177/02601060221083079]. This finding has generated substantial discussion, however, it has often lacked clarity and context, with the term 'high-protein' being used unqualified. Firstly, diets < 3.4 g/kg/day are not associated with a consistent decrease in testosterone. Secondly, the average protein intake is ∼1.3 g/kg/day, conventional 'high-protein' diets are ∼1.8-3 g/kg/day and the vast majority of athletes are < 3.4 g/kg/day; meaning very few individuals will ever surpass 3.4 g/kg/day. To avoid such confusion in the future, the following definitions are proposed: very high (> 3.4 g/kg/day), high (1.9-3.4 g/kg/day), moderate (1.25-1.9 g/kg/day) and low (<1.25 g/kg/day). Using these, very high-protein diets (> 3.4 g/kg/day) appear to decrease testosterone, however high- and moderate-protein diets (1.25-3.4 g/kg/day) do not.
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Affiliation(s)
- Joseph Whittaker
- The School of Allied Health and Community, 8709University of Worcester, UK
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7
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Holmberg PM, Harrison PW, Jenkins DG, Kelly VG. Factors Modulating the Priming Response to Resistance and Stretch-Shortening Cycle Exercise Stimuli. Strength Cond J 2022. [DOI: 10.1519/ssc.0000000000000728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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You Y, Wang D, Liu J, Chen Y, Ma X, Li W. Physical Exercise in the Context of Air Pollution: An Emerging Research Topic. Front Physiol 2022; 13:784705. [PMID: 35295574 PMCID: PMC8918627 DOI: 10.3389/fphys.2022.784705] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 01/18/2022] [Indexed: 12/12/2022] Open
Abstract
Physical exercise (PE) brings physiological benefits to human health; paradoxically, exposure to air pollution (AP) is harmful. Hence, the combined effects of AP and PE are interesting issues worth exploring. The objective of this study is to review literature involved in AP-PE fields to perform a knowledge-map analysis and explore the collaborations, current hotspots, physiological applications, and future perspectives. Herein, cluster, co-citation, and co-occurrence analysis were applied using CiteSpace and VOSviewer software. The results demonstrated that AP-PE domains have been springing up and in rapid growth since the 21st century. Subsequently, active countries and institutions were identified, and the productive institutions were mainly located in USA, China, UK, Spain, and Canada. Developed countries seemed to be the major promoters. Additionally, subject analysis found that environmental science, public health, and sports medicine were the core subjects, and multidimensional communications were forming. Thereafter, a holistic presentation of reference co-citation clusters was conducted to discover the research topics and trace the development focuses. Youth, elite athletes, and rural population were regarded as the noteworthy subjects. Commuter exposure and moderate aerobic exercise represented the common research context and exercise strategy, respectively. Simultaneously, the research hotspots and application fields were elaborated by keyword co-occurrence distribution. It was noted that physiological adaptations including respiratory, cardiovascular, metabolic, and mental health were the major themes; oxidative stress and inflammatory response were the mostly referred mechanisms. Finally, several challenges were proposed, which are beneficial to promote the development of the research field. Molecular mechanisms and specific pathways are still unknown and the equilibrium points and dose-effect relationships remain to be further explored. We are highly confident that this study provides a unique perspective to systematically and comprehensively review the pieces of AP-PE research and its related physiological mechanisms for future investigations.
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Affiliation(s)
- Yanwei You
- Division of Sports Science and Physical Education, Tsinghua University, Beijing, China
| | - Dizhi Wang
- Division of Sports Science and Physical Education, Tsinghua University, Beijing, China
| | - Jianxiu Liu
- Division of Sports Science and Physical Education, Tsinghua University, Beijing, China
| | - Yuquan Chen
- Institute of Medical Information/Library, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Xindong Ma
- Division of Sports Science and Physical Education, Tsinghua University, Beijing, China
- *Correspondence: Xindong Ma
| | - Wenkai Li
- China Table Tennis College, Shanghai University of Sport, Shanghai, China
- Wenkai Li
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9
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Zamir A, Ben-Zeev T, Hoffman JR. Manipulation of Dietary Intake on Changes in Circulating Testosterone Concentrations. Nutrients 2021; 13:3375. [PMID: 34684376 PMCID: PMC8538516 DOI: 10.3390/nu13103375] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Revised: 09/22/2021] [Accepted: 09/23/2021] [Indexed: 12/22/2022] Open
Abstract
Elevations in the circulating concentration of androgens are thought to have a positive effect on the anabolic processes leading to improved athletic performance. Anabolic-androgenic steroids have often been used by competitive athletes to augment this effect. Although there has been concerted effort on examining how manipulating training variables (e.g., intensity and volume of training) can influence the androgen response to exercise, there has been much less effort directed at understanding how changes in both macronutrient and micronutrient intake can impact the androgen response. Thus, the focus of this review is to examine the effect that manipulating energy and nutrient intake has on circulating concentrations of testosterone and what the potential mechanism is governing these changes.
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Affiliation(s)
| | | | - Jay R. Hoffman
- Department of Physical Therapy, Faculty of Health Sciences, Ariel University, 40700 Ariel, Israel; (A.Z.); (T.B.-Z.)
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10
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Ruiz-Castellano C, Espinar S, Contreras C, Mata F, Aragon AA, Martínez-Sanz JM. Achieving an Optimal Fat Loss Phase in Resistance-Trained Athletes: A Narrative Review. Nutrients 2021; 13:nu13093255. [PMID: 34579132 PMCID: PMC8471721 DOI: 10.3390/nu13093255] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 09/13/2021] [Accepted: 09/15/2021] [Indexed: 12/14/2022] Open
Abstract
Managing the body composition of athletes is a common practice in the field of sports nutrition. The loss of body weight (BW) in resistance-trained athletes is mainly conducted for aesthetic reasons (bodybuilding) or performance (powerlifting or weightlifting). The aim of this review is to provide dietary–nutritional strategies for the loss of fat mass in resistance-trained athletes. During the weight loss phase, the goal is to reduce the fat mass by maximizing the retention of fat-free mass. In this narrative review, the scientific literature is evaluated, and dietary–nutritional and supplementation recommendations for the weight loss phase of resistance-trained athletes are provided. Caloric intake should be set based on a target BW loss of 0.5–1.0%/week to maximize fat-free mass retention. Protein intake (2.2–3.0 g/kgBW/day) should be distributed throughout the day (3–6 meals), ensuring in each meal an adequate amount of protein (0.40–0.55 g/kgBW/meal) and including a meal within 2–3 h before and after training. Carbohydrate intake should be adapted to the level of activity of the athlete in order to training performance (2–5 g/kgBW/day). Caffeine (3–6 mg/kgBW/day) and creatine monohydrate (3–5 g/day) could be incorporated into the athlete’s diet due to their ergogenic effects in relation to resistance training. The intake of micronutrients complexes should be limited to special situations in which there is a real deficiency, and the athlete cannot consume through their diet.
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Affiliation(s)
| | - Sergio Espinar
- Faculty of Health Sciences, UCAM Universidad Católica de Murcia, 30107 Murcia, Spain;
- Correspondence:
| | - Carlos Contreras
- Faculty of Health Sciences, UCAM Universidad Católica de Murcia, 30107 Murcia, Spain;
| | - Fernando Mata
- Centro de Estudios Avanzados en Nutrición (CEAN), 14010 Córdoba, Spain;
| | - Alan A. Aragon
- Department of Family and Consumer Sciences, California State University, Northridge, CA 91330, USA;
| | - José Miguel Martínez-Sanz
- Research Group on Food and Nutrition (ALINUT), Nursing Department, Faculty of Health Sciences, University of Alicante, 03690 Alicante, Spain;
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Wilson JM, Lowery RP, Roberts MD, Sharp MH, Joy JM, Shields KA, Partl JM, Volek JS, D'Agostino DP. Effects of Ketogenic Dieting on Body Composition, Strength, Power, and Hormonal Profiles in Resistance Training Men. J Strength Cond Res 2021; 34:3463-3474. [PMID: 28399015 DOI: 10.1519/jsc.0000000000001935] [Citation(s) in RCA: 70] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Wilson, JM, Lowery, RP, Roberts, MD, Sharp, MH, Joy, JM, Shields, KA, Partl, JM, Volek, JS, and D'Agostino, DP. Effects of ketogenic dieting on body composition, strength, power, and hormonal profiles in resistance training men. J Strength Cond Res 34(12): 3463-3474, 2020-This study investigated the impact of an isocaloric and isonitrogenous ketogenic diet (KD) versus a traditional western diet (WD) on changes in body composition, performance, blood lipids, and hormonal profiles in resistance-trained athletes. Twenty-five college-aged men were divided into a KD or traditional WD from weeks 1 to 10, with a reintroduction of carbohydrates from weeks 10 to 11, while participating in a resistance training program. Body composition, strength, power, and blood lipid profiles were determined at weeks 0, 10, and 11. A comprehensive metabolic panel and testosterone levels were also measured at weeks 0 and 11. Lean body mass (LBM) increased in both the KD and WD groups (2.4% and 4.4%, p < 0.01) at week 10. However, only the KD group showed an increase in LBM between weeks 10 and 11 (4.8%, p < 0.0001). Finally, fat mass decreased in both the KD (-2.2 ± 1.2 kg) and WD groups (-1.5 ± 1.6 kg). Strength and power increased to the same extent in the WD and KD conditions from weeks 1 to 11. No changes in any serum lipid measures occurred from weeks 1 to 10; however, a rapid reintroduction of carbohydrate from weeks 10 to 11 raised plasma triglyceride levels in the KD group. Total testosterone increased significantly from weeks 0 to 11 in the KD diet (118 ng·dl) as compared to the WD (-36 ng·dl) from pre to post while insulin did not change. The KD can be used in combination with resistance training to cause favorable changes in body composition, performance, and hormonal profiles in resistance-trained men.
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Affiliation(s)
| | - Ryan P Lowery
- Applied Science & Performance Institute, Tampa, Florida.,Department of Health and Human Performance, Concordia University Chicago, River Forest, Illinois
| | - Michael D Roberts
- Molecular and Applied Sciences Laboratory, School of Kinesiology, Auburn University, Auburn, Alabama
| | | | - Jordan M Joy
- Department of Nutrition and Food Science, Texas Woman's University, Denton, Texas
| | - Kevin A Shields
- Department of Health Sciences and Human Performance, The University of Tampa, Tampa, Florida
| | - Jeremy M Partl
- Department of Health Sciences and Human Performance, The University of Tampa, Tampa, Florida
| | - Jeff S Volek
- Department of Human Sciences, Kinesiology Program, Ohio State University, Columbus, Ohio; and
| | - Dominic P D'Agostino
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida
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12
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Eljawad MA, Se'eda H, Ghozy S, El-Qushayri AE, Elsherif A, Elkassar AH, Atta-Allah MH, Ibrahim W, Elmahdy MA, Islam SMS. Pornography Use Prevalence and Associated Factors in Arab Countries: A Multinational Cross-Sectional Study of 15,027 Individuals. J Sex Med 2021; 18:539-548. [PMID: 33526399 DOI: 10.1016/j.jsxm.2020.12.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 11/06/2020] [Accepted: 12/17/2020] [Indexed: 11/20/2022]
Abstract
BACKGROUND There has been a tangible increase in pornography consumption during the past decade, with the absence of a large-scale study of Arab countries. AIM The present study aimed to assess the prevalence of pornography viewing and its associated risk factors in Arab countries. METHODS A large cross-sectional online survey was carried out recruiting participants without restrictions on the age, socioeconomic level, job, or educational level. Multivariable logistic regression analysis was performed to identify possible risk factors for viewing porn and results were expressed as odds ratios (ORs) and 95% confidence interval (95% CI). OUTCOMES Main outcomes were pornography viewing (first exposure and frequency), the perceptions of this act, use of spare time, physical activity (exercising), and frequency of psychiatrist visits. RESULTS The final number of participants included in the study was 15027 participants with a mean age ± standard deviation of 23.82 years ± 24.99. Most of the participants were men (84.56%), living with parents (81.71%), and 60.51% university graduates. There were statistically significant differences (P < .001) in the attitude and practice of men compared with women throughout all tested variables. Frequent pornography viewing was associated with male gender (OR [95% CI] = 7.08 [6.43 to 7.81]; P < .001) and age group ≤15 years (OR [95% CI] = 1.33 [1.01 to 1.75]; P = .044). By contrast, higher education was inversely associated with viewing rates reaching the lowest level in PhD awardees (OR [95% CI] = 0.36 [0.26 to 0.51]; P = .003). It was also noted that regular exercising (OR [95% CI] = 0.66 [0.58 to 0.74]; P < .001) was associated with a reduction in pornography viewing rates. CLINICAL IMPLICATIONS Young age, male gender, and lower educational level are all predictors for higher pornography viewing and should be considered when designing public health intervention in a related context. STRENGTHS AND LIMITATIONS This is the first large-scale multi-national survey to be conducted in Arab countries to investigate pornography viewing. The main limitations were the cross-sectional design (cannot indicate causality) and the self-report nature (liable to social desirability and recall bias). CONCLUSION Pornography viewing is common in Arab countries and associated with some personal and behavioral factors. Eljawad MA, Se'eda H, Ghozy S, et al. Pornography Use Prevalence and Associated Factors in Arab Countries: A Multinational Cross-Sectional Study of 15,027 Individuals. J Sex Med 2021;18:539-548.
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Affiliation(s)
- Mohamed Abd Eljawad
- Internal Medicine Department, Jazan Armed Forces Hospital, Jazan, Saudi Arabia; Academic Research Division, The Aware Academy, Cairo, Egypt
| | - Hussien Se'eda
- Academic Research Division, The Aware Academy, Cairo, Egypt; Faculty of Medicine, Minia University, Minia, Egypt
| | - Sherief Ghozy
- Faculty of Medicine, Mansoura University, Mansoura, Egypt.
| | | | - Ahmed Elsherif
- Academic Research Division, The Aware Academy, Cairo, Egypt; Faculty of Medicine, Al-Azhar University, Cairo, Egypt
| | - Ahmed Hussein Elkassar
- Academic Research Division, The Aware Academy, Cairo, Egypt; Faculty of Medicine, Minia University, Minia, Egypt
| | - Mohammed H Atta-Allah
- Academic Research Division, The Aware Academy, Cairo, Egypt; Faculty of Medicine, Ain Shams University, Cairo, Egypt
| | - Wael Ibrahim
- Academic Research Division, The Aware Academy, Cairo, Egypt; Student Counselor, Australian Islamic College, Kewdale, Australia
| | - Mohamed A Elmahdy
- Psychiatry Department, Damietta Faculty of Medicine, Al-Azhar- University, Damietta, Egypt
| | - Sheikh Mohammed Shariful Islam
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Melbourne, Australia
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Bagheri R, Hooshmand Moghadam B, Ashtary-Larky D, Forbes SC, Candow DG, Galpin AJ, Eskandari M, Kreider RB, Wong A. Whole Egg Vs. Egg White Ingestion During 12 weeks of Resistance Training in Trained Young Males: A Randomized Controlled Trial. J Strength Cond Res 2020; 35:411-419. [DOI: 10.1519/jsc.0000000000003922] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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14
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Wrzosek M, Woźniak J, Włodarek D. The Combination of a Diversified Intake of Carbohydrates and Fats and Supplementation of Vitamin D in a Diet Does Not Affect the Levels of Hormones (Testosterone, Estradiol, and Cortisol) in Men Practicing Strength Training for the Duration of 12 Weeks. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:E8057. [PMID: 33139636 PMCID: PMC7662710 DOI: 10.3390/ijerph17218057] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 10/28/2020] [Accepted: 10/30/2020] [Indexed: 12/13/2022]
Abstract
This study aims to verify the extent to which a diversification of carbohydrates and fats intake in a diet, together with the reduction in vitamin D deficiency, impact the levels of hormones (testosterone, estradiol, cortisol) and Sex Hormone Binding Globulin (SHGB) in men doing strength training. The research involved 55 men aged 19-35. The participants were divided into two groups following two interventional diets for 12 weeks: high-fat diet (LCHF) or high-carb diet (LFHC), which were applied to satisfy the caloric requirements of each participant. Moreover, vitamin D supplementation was included. Moreover, both before and after following interventional diets, the level of hormones in participant's blood was examined. After 12 weeks of following interventional diets in both groups, no changes of the levels of testosterone and estradiol, as well as SHGB, were found. The cortisol level in both groups decreased; however, only in the LFHC group was the change statistically significant (p = 0.03) and amounted to -3.5% (the cortisol level on an empty stomach in this group decreased from 14.17 ± 3.35 to 13.93 ± 2.63 mcg/dl). In both groups, the supplementation of vitamin D brought about a significant change in the level of vitamin D metabolite (25 (OH) D) (p = 0.01). In the LCHF group, the level of metabolite increased by 95%, and by 58.3% in the LFHC group. The increase in vitamin D metabolite in blood was higher in the LCHF group than the LFHC group, which might have resulted from the supplementation of this vitamin.
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Affiliation(s)
| | - Jakub Woźniak
- Department of Dietetics, Instutute of Human Nutrition Sciences, Warsaw University of Life Sciences (WULS—SGGW), Nowoursynowska 159 C, 02-776 Warsaw, Poland; (M.W.); (D.W.)
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15
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Nemeth M, Wallner B, Schuster D, Siutz C, Quint R, Wagner KH, Millesi E. Effects of dietary fatty acids on the social life of male Guinea pigs from adolescence to adulthood. Horm Behav 2020; 124:104784. [PMID: 32504693 DOI: 10.1016/j.yhbeh.2020.104784] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 05/29/2020] [Accepted: 05/30/2020] [Indexed: 12/19/2022]
Abstract
Dietary intake of polyunsaturated fatty acids (PUFAs) or saturated fatty acids (SFAs) differently modulates neurophysiological and behavioral functions in response to altered hypothalamic-pituitary-adrenal (HPA)-axis activity and an individual's development. In this context, an individual's social environment, including social interactions and social hierarchies, is closely related to hormone concentrations and possibly interacts with dietary fatty acid effects. We investigated if dietary supplementation with walnut oil (high in PUFAs) and coconut fat (high in SFAs), compared to a control group, affects body mass gain, cortisol and testosterone concentrations, plasma fatty acids, and social behavior in male domestic guinea pigs from adolescence to adulthood. For analyses of cortisol and testosterone concentrations, social interactions were included as covariates in order to consider effects of social behavior on hormone concentrations. Our results revealed that SFAs increased escalated conflicts like fights and stimulated cortisol and testosterone concentrations, which limited body mass gain and first-year survival. PUFAs did not remarkably affect social behavior and hormone concentrations, but enabled the strongest body mass gain, which probably resulted from an energetic advantage. Neither sociopositive nor agonistic behaviors explained age-specific differences in hormone concentrations between groups. However, a high number of subdominant individuals and lower testosterone concentrations were related to increased cortisol concentrations in adult PUFA males. Our findings demonstrate the importance of dietary fatty acids regarding behavioral and endocrine developmental processes and adaptations to the social environment by modulating HPA-axis function and body homeostasis.
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Affiliation(s)
- Matthias Nemeth
- Department of Behavioral and Cognitive Biology, Faculty of Life Sciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria.
| | - Bernard Wallner
- Department of Behavioral and Cognitive Biology, Faculty of Life Sciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Daniela Schuster
- Department of Behavioral and Cognitive Biology, Faculty of Life Sciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Carina Siutz
- Department of Behavioral and Cognitive Biology, Faculty of Life Sciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Ruth Quint
- Department of Nutritional Sciences, Faculty of Life Sciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Karl-Heinz Wagner
- Department of Nutritional Sciences, Faculty of Life Sciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Eva Millesi
- Department of Behavioral and Cognitive Biology, Faculty of Life Sciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
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16
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Philip AS, Rajashekhar B, Shekaraiah S, N R. Analysis of Phonatory and Respiratory Functions in Physical Fitness Instructors in Comparison to Controls. J Voice 2020; 35:746-752. [PMID: 32057610 DOI: 10.1016/j.jvoice.2020.01.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 01/16/2020] [Accepted: 01/17/2020] [Indexed: 10/25/2022]
Abstract
OBJECTIVE Professional voice users form an increasing part of our population. Physical fitness instructors listed as professional voice users are at risk for voice problem as they perform vigorous exercises, instruct at the same time and compete vocally with loud background music. Hence, there is a dire need to study the voice problems in this population. The current study was aimed at investigating the phonatory and respiratory functions in physical fitness instructors in comparison to a control group. STUDY DESIGN Cross-sectional study design MATERIALS AND METHODS: Fifty physical fitness instructors (48 males and two females) and 50 controls (45 males and five females) with the age range of 18-40 years were initially enrolled in the study. The phonatory function measures (perceptual, physiological, and acoustic) and respiratory function measures (aerodynamics) were obtained. RESULTS Following the data analysis only for male participants, the majority of the perceptual parameters such as grade, roughness, breathiness, and strain showed significant increase in the clinical group compared to controls (P < 0.05). Similarly, few acoustic parameters such as fundamental frequency (F0) related parameters such as average F0, mean F0, highest fundamental frequency (Fhi) and lowest fundamental frequency (Flo) showed significant decrease in clinical group compared to controls (P < 0.05). CONCLUSIONS Few perceptual and acoustic parameters are sensitive in differentiating the voice problems in physical fitness instructors from the controls. The significant perceptual and acoustic parameters implied that they are at risk for developing voice problems. Hence, early identification and prevention of voice problems in this population is warranted.
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Affiliation(s)
- Anju Susan Philip
- Department of Speech and Hearing, Manipal College of Health Professions (MCHP), Manipal Academy of Higher Education (MAHE), Manipal, Karnataka, India
| | - Bellur Rajashekhar
- Department of Speech and Hearing, Manipal College of Health Professions (MCHP), Manipal Academy of Higher Education (MAHE), Manipal, Karnataka, India
| | - Sheela Shekaraiah
- Department of Speech and Hearing, Manipal College of Health Professions (MCHP), Manipal Academy of Higher Education (MAHE), Manipal, Karnataka, India.
| | - Ravishankar N
- Department of Statistics, MAHE, Manipal, Karnataka, India
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17
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Kang J, Ratamess NA, Faigenbaum AD, Bush JA. Ergogenic Properties of Ketogenic Diets in Normal-Weight Individuals: A Systematic Review. J Am Coll Nutr 2020; 39:665-675. [PMID: 32039654 DOI: 10.1080/07315724.2020.1725686] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Ketogenic diets (KDs) have received increasing attention among athletes and physically active individuals. However, the question as to whether and how the diet could benefit this healthy cohort remains unclear.Purpose: This study was designed to systematically review the existing evidence concerning the effect of KDs on body composition, aerobic and anaerobic capacity, muscle development, and sports performance in normal-weight individuals including athletes.Methods: A systematic search of English literature was conducted through electronic databases including PubMed, EBSCOhost, and Google Scholar. Upon the use of search criteria, 23 full-text original human studies involving non-obese participants were included in this review. For more stratified and focused analysis, these articles were further categorized based on the outcomes being examined including 1) body mass (BM) and %fat, 2) substrate utilization, 3) blood substrate and hormonal responses, 4) aerobic capacity and endurance performance, and 5) strength, power, and anaerobic capacity.Results: Our review indicates that a non-calorie-restricted KD carried out for ≥3 weeks can produce a modest reduction in BM and %fat, while maintaining fat-free mass. This diet leads to augmented use of fat as fuel, but this adaptation doesn't seem to improve endurance performance. Additionally, ad libitum KDs combined with resistance training will pose no harm to developing strength and power, especially when protein intake is increased modestly.Conclusions: It appears that a non-calorie-restricted KD provides minimal ergogenic benefits in normal-weight individuals including athletes, but can be used for optimizing BM and body composition without compromising aerobic and anaerobic performance. Key teaching pointsKetogenic diets have received increasing attention among athletes and physically active individuals.It remains elusive as to whether ketogenic diets could confer ergogenic benefits for those who are normal weight but want to use the diet to improve fitness and performance.An interesting dilemma exists in that ketogenic diets can reduce body mass and %fat and increase fat oxidation, but they can also decrease glycogen stores and limit sports performance.This review concludes that a non-calorie-restricted ketogenic diet provides minimal ergogenic benefits in normal-weight individuals, but can be used to optimize body mass and composition without compromising athletic performance.This finding can be important for esthetic or weight-sensitive athletes because the diet may allow them to reach a target body mass without having to sacrifice athletic performance.The ketogenic diet-induced metabolic adaptations require a state of ketosis, and thus caution should be taken because an excessive increase in ketone bodies can be detrimental to health.
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Affiliation(s)
- Jie Kang
- Human Performance Laboratory, The College of New Jersey, Ewing, New Jersey, USA
| | - Nicholas A Ratamess
- Human Performance Laboratory, The College of New Jersey, Ewing, New Jersey, USA
| | - Avery D Faigenbaum
- Human Performance Laboratory, The College of New Jersey, Ewing, New Jersey, USA
| | - Jill A Bush
- Human Performance Laboratory, The College of New Jersey, Ewing, New Jersey, USA
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18
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Abstract
The popularity of physique sports is increasing, yet there are currently few comprehensive nutritional guidelines for these athletes. Physique sport now encompasses more than just a short phase before competition and offseason guidelines have recently been published. Therefore, the goal of this review is to provide an extensive guide for male and female physique athletes in the contest preparation and recovery period. As optimal protein intake is largely related to one’s skeletal muscle mass, current evidence supports a range of 1.8-2.7 g/kg. Furthermore, as a benefit from having adequate carbohydrate to fuel performance and activity, low-end fat intake during contest preparation of 10-25% of calories allows for what calories remain in the “energy budget” to come from carbohydrate to mitigate the negative impact of energy restriction and weight loss on training performance. For nutrient timing, we recommend consuming four or five protein boluses per day with one consumed near training and one prior to sleep. During competition periods, slower rates of weight loss (≤0.5% of body mass per week) are preferable for attenuating the loss of fat-free mass with the use of intermittent energy restriction strategies, such as diet breaks and refeeds, being possibly beneficial. Additionally, physiological and psychological factors are covered, and potential best-practice guidelines are provided for disordered eating and body image concerns since physique athletes present with higher incidences of these issues, which may be potentially exacerbated by certain traditional physique practices. We also review common peaking practices, and the critical transition to the post-competition period.
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19
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Jensen AE, Arrington LJ, Turcotte LP, Kelly KR. Hormonal balance and nutritional intake in elite tactical athletes. Steroids 2019; 152:108504. [PMID: 31586604 DOI: 10.1016/j.steroids.2019.108504] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 08/14/2019] [Accepted: 09/24/2019] [Indexed: 10/25/2022]
Abstract
Chronic exposure to multifactorial stress, such as that endured by elite military operators, may lead to overtraining syndrome and negatively impact hormonal regulation. In acute settings (<6 mos), military training has been shown to lead to hormonal dysfunction; however, less is known about the consequences of long-term military training. Thus, the purpose of this study was to determine the chronic effects of military operations and training on the hormone profile of elite military operators. A cross-sectional, random sample of active duty elite US military operators (n = 65, age = 29.8 ± 1.0 yrs, height = 178.4 ± 0.7 cm, weight = 85.1 ± 2.0 kg) concomitantly engaged in rigorous physical training were recruited to participate in the study. Following an overnight fast, waking plasma concentrations of luteinizing hormone, total testosterone (TT), free testosterone, sex-hormone binding globulin, cortisol, thyroid stimulating hormone, triiodothyronine, and thyroxine were obtained. Data were analyzed for correlations and compared against normative reference values. There was a significant positive correlation between TT and cortisol (R2 = 0.07; P = 0.038). In addition, 43% of the participants (n = 28) had TT below age-based normative reference ranges. These results indicate that long-term military operations and training may place a large burden on the operators and depress or alter the hypothalamic pituitary, adrenal, gonadal, and thyroid axes.
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Affiliation(s)
- Andrew E Jensen
- Naval Health Research Center, Warfighter Performance Department, 140 Sylvester Road, San Diego, CA 92106, United States; Leidos Inc., 10260 Campus Point Drive, San Diego, CA 92121, United States; University of Southern California, Biological Sciences, Human and Evolutionary Biology, Dornsife College of Letters, Arts and Sciences, 3616 Trousdale Parkway, AHF 247, Los Angeles, CA 90089, United States
| | - Laura J Arrington
- Naval Health Research Center, Warfighter Performance Department, 140 Sylvester Road, San Diego, CA 92106, United States; Leidos Inc., 10260 Campus Point Drive, San Diego, CA 92121, United States
| | - Lorraine P Turcotte
- University of Southern California, Biological Sciences, Human and Evolutionary Biology, Dornsife College of Letters, Arts and Sciences, 3616 Trousdale Parkway, AHF 247, Los Angeles, CA 90089, United States
| | - Karen R Kelly
- Naval Health Research Center, Warfighter Performance Department, 140 Sylvester Road, San Diego, CA 92106, United States; University of Southern California, Biological Sciences, Human and Evolutionary Biology, Dornsife College of Letters, Arts and Sciences, 3616 Trousdale Parkway, AHF 247, Los Angeles, CA 90089, United States.
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20
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Schwartz A, Hunschede S, Lacombe RJS, Chatterjee D, Sánchez-Hernández D, Kubant R, Bazinet RP, Hamilton JK, Anderson GH. Acute decrease in plasma testosterone and appetite after either glucose or protein beverages in adolescent males. Clin Endocrinol (Oxf) 2019; 91:295-303. [PMID: 31055857 DOI: 10.1111/cen.14005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 05/02/2019] [Accepted: 05/03/2019] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Chronic testosterone blood concentrations associate with food intake (FI), but acute effects of testosterone on appetite and effect of protein and glucose consumption on testosterone response have had little examination. METHODS In a randomized, crossover study, twenty-three adolescent (12-18 years old) males were given beverages containing either: (a) whey protein (1 g/kg body weight), (b) glucose (1 g/kg body weight) or (c) a calorie-free control (C). Plasma testosterone, luteinizing hormone (LH), GLP-1 (active), ghrelin (acylated), glucose, insulin and subjective appetite were measured prior (0) and at 20, 35 and 65 minutes after the consumption of the beverage. FI at an ad libitum pizza meal was assessed at 85 minutes. RESULTS Testosterone decreased acutely to 20 minutes after both protein and glucose with the decrease continuing after protein but not glucose to 65 minutes (P = 0.0382). LH was also decreased by both protein and glucose, but glucose had no effect at 20 minutes in contrast to protein (P < 0.001). Plasma testosterone concentration correlated positively with LH (r = 0.58762, P < 0.0001) and negatively with GLP-1 (r = -0.50656, P = 0.0003). No associations with appetite, ghrelin or glycaemic markers were found. Food intake was not affected by treatments. CONCLUSION Protein or glucose ingestion results in acute decreases in both plasma testosterone and LH in adolescent males. The physiological significance of this response remains to be determined as no support for testosterone's role in acute regulation of food intake was found.
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Affiliation(s)
- Alexander Schwartz
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
- Division of Endocrinology, Department of Paediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Sascha Hunschede
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Russel John Scott Lacombe
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Diptendu Chatterjee
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Diana Sánchez-Hernández
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Ruslan Kubant
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Richard Paul Bazinet
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Jill K Hamilton
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
- Division of Endocrinology, Department of Paediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Gerald Harvey Anderson
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
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21
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Anaerobic Performance after a Low-Carbohydrate Diet (LCD) Followed by 7 Days of Carbohydrate Loading in Male Basketball Players. Nutrients 2019; 11:nu11040778. [PMID: 30987297 PMCID: PMC6520927 DOI: 10.3390/nu11040778] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 03/28/2019] [Accepted: 04/01/2019] [Indexed: 12/22/2022] Open
Abstract
Despite increasing interest among athletes and scientists on the influence of different dietary interventions on sport performance, the association between a low-carbohydrate, high-fat diet and anaerobic capacity has not been studied extensively. The aim of this study was to evaluate the effects of a low-carbohydrate diet (LCD) followed by seven days of carbohydrate loading (Carbo-L) on anaerobic performance in male basketball players. Fifteen competitive basketball players took part in the experiment. They performed the Wingate test on three occasions: after the conventional diet (CD), following 4 weeks of the LCD, and after the weekly Carbo-L, to evaluate changes in peak power (PP), total work (TW), time to peak power (TTP), blood lactate concentration (LA), blood pH, and bicarbonate (HCO3−). Additionally, the concentrations of testosterone, growth hormone, cortisol, and insulin were measured after each dietary intervention. The low-carbohydrate diet procedure significantly decreased total work, resting values of pH, and blood lactate concentration. After the low-carbohydrate diet, testosterone and growth hormone concentrations increased, while the level of insulin decreased. After the Carbo-L, total work, resting values of pH, bicarbonate, and lactate increased significantly compared with the results obtained after the low-carbohydrate diet. Significant differences after the low-carbohydrate diet and Carbo-L procedures, in values of blood lactate concentration, pH, and bicarbonate, between baseline and post exercise values were also observed. Four weeks of the low-carbohydrate diet decreased total work capacity, which returned to baseline values after the carbohydrate loading procedure. Moreover, neither the low-carbohydrate feeding nor carbohydrate loading affected peak power.
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22
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Waldman HS, Krings BM, Basham SA, Smith JEW, Fountain BJ, McAllister MJ. Effects of a 15-Day Low Carbohydrate, High-Fat Diet in Resistance-Trained Men. J Strength Cond Res 2019; 32:3103-3111. [PMID: 29076962 DOI: 10.1519/jsc.0000000000002282] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Waldman, HS, Krings, BM, Basham, SA, Smith, JW, Fountain, BJ, and McAllister, MJ. Effects of a 15-day low carbohydrate, high-fat diet in resistance-trained men. J Strength Cond Res 32(11): 3103-3111, 2018-This study examined the effects of a 15-day isocaloric low carbohydrate (<25% E), high-fat (>50% E) (LCHF) diet on physiological and metabolic alterations in resistance-trained (RT) men. College-aged RT men (n = 11) completed 4 V[Combining Dot Above]O2max tests using treadmill every 5 days during the 15-day trial. Blood was drawn intravenously pre-exercise across each experimental trial for insulin, cortisol, and glucose. Pulmonary data were collected and substrate oxidation (OXI) was calculated during exercise. Body mass decreased (p < 0.04) with no further changes in anthropometric measures. Time to exhaustion was not affected across each day. Insulin dropped below baseline values (p < 0.0005). Cortisol increased from baseline to day 5 (p < 0.004) but returned back to near baseline at day 10, whereas glucose remained within normal range throughout the duration of the study. Carbohydrate (CHO) OXI dropped (p < 0.001) from baseline to day 5, and fat OXI increased from baseline to day 5 (p < 0.0001). Heart rate decreased from baseline to day 5 (p < 0.001) and again from day 10 to 15 (p < 0.02). Oxygen uptake (V[Combining Dot Above]O2) decreased from day 5 to 10 (p < 0.0001). A nonketo LCHF diet appears to favor RT men by altering metabolic markers without decrements in aerobic performance and be a potential diet intervention used by coaches. However, the reported cardiorespiratory responses should be interpreted reasonably because of the possibility the subjects running economy improved over experimental trials.
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Affiliation(s)
- Hunter S Waldman
- Applied Physiology Laboratory, Department of Kinesiology, Mississippi State University, Starkville, Mississippi
| | - Ben M Krings
- Applied Physiology Laboratory, Department of Kinesiology, Mississippi State University, Starkville, Mississippi
| | - Steven A Basham
- Applied Physiology Laboratory, Department of Kinesiology, Mississippi State University, Starkville, Mississippi
| | - John Eric W Smith
- Applied Physiology Laboratory, Department of Kinesiology, Mississippi State University, Starkville, Mississippi
| | - Brent J Fountain
- Department of Food Science, Nutrition, and Health Promotion, Mississippi State University, Starkville, Mississippi
| | - Matthew J McAllister
- Applied Physiology Laboratory, Department of Kinesiology, Mississippi State University, Starkville, Mississippi
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23
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Tsoukos A, Veligekas P, Brown LE, Terzis G, Bogdanis GC. Delayed Effects of a Low-Volume, Power-Type Resistance Exercise Session on Explosive Performance. J Strength Cond Res 2018; 32:643-650. [DOI: 10.1519/jsc.0000000000001812] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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24
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Neto AS, Tobias-Machado M, Wroclawski ML, Fonseca FLA, Pompeo ACL, Del Giglio A. Molecular Oncogenesis of Prostate Adenocarcinoma: Role of the Human Epidermal Growth Factor Receptor 2 (HER-2/neu). TUMORI JOURNAL 2018; 96:645-9. [DOI: 10.1177/030089161009600501] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The potential mechanisms involving the genesis and growth of androgen-independent prostate cancer include super-expression of the androgen receptor (AR), in an attempt to compensate for the low androgenic plasma levels and mutations of this specific receptor, which could determine resistance to anti-androgenic therapy. However, most advanced prostate tumors have no mutations or amplifications of the AR, suggesting a potential role of non-androgenic growth factors, including epidermal growth factor (EGF), transforming growth factor α, insulin-like growth factor (IGF-1) and fibroblast growth factor. More specifically, these factors, and their receptors like EGFR (HER-1) and HER-2/neu, through paracrine and autocrine mechanisms, may contribute to the proliferation and growth of prostate cancer. Free full text available at www.tumorionline.it
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Affiliation(s)
- Ary Serpa Neto
- Urologic Oncology Division, Department of Urology, ABC Medical School (FMABC), Santo André
| | - Marcos Tobias-Machado
- Urologic Oncology Division, Department of Urology, ABC Medical School (FMABC), Santo André
- Research Institute, Albert Einstein Jewish Hospital (IEP-HIAE), São Paulo
| | - Marcelo Langer Wroclawski
- Urologic Oncology Division, Department of Urology, ABC Medical School (FMABC), Santo André
- Research Institute, Albert Einstein Jewish Hospital (IEP-HIAE), São Paulo
| | - Fernando Luiz Affonso Fonseca
- Research Institute, Albert Einstein Jewish Hospital (IEP-HIAE), São Paulo
- Oncology Division, Department of Clinical Oncology and Hematology, ABC Medicine School (FMABC), Santo André, Brazil
| | | | - Auro Del Giglio
- Research Institute, Albert Einstein Jewish Hospital (IEP-HIAE), São Paulo
- Oncology Division, Department of Clinical Oncology and Hematology, ABC Medicine School (FMABC), Santo André, Brazil
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25
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Walker S, Häkkinen K, Haff GG, Blazevich AJ, Newton RU. Acute elevations in serum hormones are attenuated after chronic training with traditional isoinertial but not accentuated eccentric loads in strength-trained men. Physiol Rep 2017; 5:5/7/e13241. [PMID: 28400506 PMCID: PMC5392527 DOI: 10.14814/phy2.13241] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 02/24/2017] [Accepted: 03/11/2017] [Indexed: 12/25/2022] Open
Abstract
It has been proposed that the maintenance of acute hormonal responses reveal an efficacy of a training stimulus to evoke ongoing increases in strength and muscle mass. We previously observed that maximum strength continued to improve throughout a 10-week period in an accentuated eccentric loading group (AEL) but not a traditional isoinertial loading (ISO) group. Therefore, this study investigated whether the magnitude of acute hormonal responses was greater (i.e., maintained) in AEL compared to ISO at the end of the training period. Subjects in AEL (eccentric load = concentric load + 40%) and ISO performed experimental loading tests (three sets of 10 repetitions in the leg press and knee extension exercises) during weeks 2 and 9 of the training period. Blood samples collected during these experimental loadings were analyzed for serum testosterone, growth hormone and cortisol concentrations. Maximum isometric knee extension torque (MVC) and lower-limb lean mass were assessed before and after 5 and 10 weeks of training. Acute testosterone, growth hormone and cortisol responses to traditional isoinertial loading were reduced at the end of the training period but were not reduced after accentuated eccentric load training (P < 0.05‒0.1 between-groups). Increases in MVC and lower-limb lean mass over weeks 6‒10 were greater in AEL compared to ISO (MVC: 7.3 ± 5.4 vs. -0.4 ± 7.2%, P = 0.026 for between-group difference; lower-limb lean mass: 1.6 ± 2.2 vs. -0.2 ± 1.4%, P = 0.063 for between-group difference). The maintenance of acute hormonal responses and continued strength gain in AEL but not ISO are consistent with the hypothesis that maintained acute responses indicate an efficacy of a training stimulus to evoke ongoing adaptation. However, since relationships between hormonal responses and training-induced adaptations were not statistically significant, the data suggest that tracking of acute hormonal responses on an individual level may not provide a sensitive enough guide for decisions regarding program design and periodization.
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Affiliation(s)
- Simon Walker
- Faculty of Sport and Health Science and Neuromuscular Research Center, University of Jyväskylä, Jyväskylä, Finland .,Centre for Exercise and Sports Science Research (CESSR), Edith Cowan University, Joondalup, Australia
| | - Keijo Häkkinen
- Faculty of Sport and Health Science and Neuromuscular Research Center, University of Jyväskylä, Jyväskylä, Finland
| | - Guy Gregory Haff
- Centre for Exercise and Sports Science Research (CESSR), Edith Cowan University, Joondalup, Australia
| | - Anthony J Blazevich
- Centre for Exercise and Sports Science Research (CESSR), Edith Cowan University, Joondalup, Australia
| | - Robert U Newton
- Institute of Human Performance, The University of Hong Kong, Hong Kong, China
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Zhao JL, Zhao YY, Zhu WJ. A high-fat, high-protein diet attenuates the negative impact of casein-induced chronic inflammation on testicular steroidogenesis and sperm parameters in adult mice. Gen Comp Endocrinol 2017; 252:48-59. [PMID: 28743557 DOI: 10.1016/j.ygcen.2017.07.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 06/30/2017] [Accepted: 07/16/2017] [Indexed: 12/16/2022]
Abstract
The interaction between obesity and chronic inflammation has been studied. Diet-induced obesity or chronic inflammation could reduce the testicular functions of males. However, the mechanism underlying the reproductive effects of fattening foods in males with or without chronic inflammation still needs further discussion. This study was aimed to investigate the effects of high-fat, high-protein diet on testicular steroidogenesis and sperm parameters in adult mice under physiological and chronic inflammatory conditions. Because casein can trigger a non-infectious systemic inflammatory response, we used casein injection to induce chronic inflammation in male adult Kunming mice. Twenty-four mice were randomly and equally divided into four groups: (i) normal diet+saline (Control); (ii) normal diet+casein (ND+CS); (iii) high-fat, high-protein diet+saline (HFPD+SI); (iv) high-fat, high-protein diet+casein (HFPD+CS). After 8weeks, there was a significant increase in body weight for groups HFPD+SI and HFPD+CS and a decrease in group ND+CS compared with the control. The serum levels of tumor necrosis factor alpha (TNF-α), interleukin-10 (IL-10) and lipid profiles were increased markedly in groups ND+CS, HFPD+SI and HFPD+CS compared with the control. A remarkable reduction of serum adiponectin level occurred in group HFPD+CS compared with group ND+CS. Sperm parameters (sperm count, viability and abnormality) were also adversely affected in groups ND+CS and HFPD+SI. Groups ND+CS and HFPD+SI showed severe pathological changes in testicular tissues. Semiquantitative RT-PCR, Western blot and immunohistochemical staining also showed significant reductions in both testicular mRNA and protein levels of steroidogenic acute regulatory (StAR) and cytochrome P450scc (CYP11A1) in groups HFPD+SI and HFPD+CS compared with the control, whereas testicular mRNA and protein levels of 3β-hydroxysteroid dehydrogenase (3β-HSD) in groups HFPD+SI and HFPD+CS significantly increased. The mRNA and protein levels of the StAR and 3β-HSD in group HFPD+CS were both higher than those of in group ND+CS. These results indicated that Kunming male mice with high-fat, high-protein diet and casein injection for 8weeks can be used to establish a diet-induced obesity and chronic systemic inflammation. The sperm parameters in groups ND+CS and HFPD+SI decreased accompanied by pathological changes of testicular tissue. This resultant effect of reduced serum testosterone levels was associated with the overproduction of TNF-α and IL-10 and down-regulation of StAR and CYP11A1. Under the same casein-induced chronic inflammation condition, the mice with high-fat, high-protein diet had better testicular steroidogenesis activity and sperm parameters compared with the mice in normal diet, indicating that the mice with casein-induced inflammatory injury consuming a high-fat, high-protein diet gained weight normally, reduced serum adiponectin level and increased testosterone production by an upregulation of 3β-HSD expression. High-fat, high-protein diet attenuated the negative impact of casein-induced chronic inflammation on testicular steroidogenesis and sperm parameters.
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Affiliation(s)
- Jing-Lu Zhao
- Department of Developmental and Regenerative Biology, College of Life Science and Technology, Jinan University, Guangdong, Guangzhou 510632, China
| | - Yu-Yun Zhao
- College of Chemical and Biological Engineering, Hunan University of Science and Engineering, Hunan, Yongzhou 425199, China
| | - Wei-Jie Zhu
- Department of Developmental and Regenerative Biology, College of Life Science and Technology, Jinan University, Guangdong, Guangzhou 510632, China.
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Rogerson D. Vegan diets: practical advice for athletes and exercisers. J Int Soc Sports Nutr 2017; 14:36. [PMID: 28924423 PMCID: PMC5598028 DOI: 10.1186/s12970-017-0192-9] [Citation(s) in RCA: 96] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 09/03/2017] [Indexed: 02/07/2023] Open
Abstract
With the growth of social media as a platform to share information, veganism is becoming more visible, and could be becoming more accepted in sports and in the health and fitness industry. However, to date, there appears to be a lack of literature that discusses how to manage vegan diets for athletic purposes. This article attempted to review literature in order to provide recommendations for how to construct a vegan diet for athletes and exercisers. While little data could be found in the sports nutrition literature specifically, it was revealed elsewhere that veganism creates challenges that need to be accounted for when designing a nutritious diet. This included the sufficiency of energy and protein; the adequacy of vitamin B12, iron, zinc, calcium, iodine and vitamin D; and the lack of the long-chain n-3 fatty acids EPA and DHA in most plant-based sources. However, via the strategic management of food and appropriate supplementation, it is the contention of this article that a nutritive vegan diet can be designed to achieve the dietary needs of most athletes satisfactorily. Further, it was suggested here that creatine and β-alanine supplementation might be of particular use to vegan athletes, owing to vegetarian diets promoting lower muscle creatine and lower muscle carnosine levels in consumers. Empirical research is needed to examine the effects of vegan diets in athletic populations however, especially if this movement grows in popularity, to ensure that the health and performance of athletic vegans is optimised in accordance with developments in sports nutrition knowledge.
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Affiliation(s)
- David Rogerson
- Academy of Sport and Physical Activity, Sheffield Hallam University, S10 2BP, Sheffield, UK
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Bi-stability in type 2 diabetes mellitus multi-organ signalling network. PLoS One 2017; 12:e0181536. [PMID: 28767672 PMCID: PMC5540287 DOI: 10.1371/journal.pone.0181536] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 07/03/2017] [Indexed: 01/21/2023] Open
Abstract
Type 2 diabetes mellitus (T2DM) is believed to be irreversible although no component of the pathophysiology is irreversible. We show here with a network model that the apparent irreversibility is contributed by the structure of the network of inter-organ signalling. A network model comprising all known inter-organ signals in T2DM showed bi-stability with one insulin sensitive and one insulin resistant attractor. The bi-stability was made robust by multiple positive feedback loops suggesting an evolved allostatic system rather than a homeostatic system. In the absence of the complete network, impaired insulin signalling alone failed to give a stable insulin resistant or hyperglycemic state. The model made a number of correlational predictions many of which were validated by empirical data. The current treatment practice targeting obesity, insulin resistance, beta cell function and normalization of plasma glucose failed to reverse T2DM in the model. However certain behavioural and neuro-endocrine interventions ensured a reversal. These results suggest novel prevention and treatment approaches which need to be tested empirically.
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Jones TW, Howatson G, Russell M, French DN. Performance and Endocrine Responses to Differing Ratios of Concurrent Strength and Endurance Training. J Strength Cond Res 2016; 30:693-702. [PMID: 26907840 DOI: 10.1519/jsc.0000000000001135] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The present study examined functional strength and endocrine responses to varying ratios of strength and endurance training in a concurrent training regimen. Thirty resistance trained men completed 6 weeks of 3 d·wk of (a) strength training (ST), (b) concurrent strength and endurance training ratio 3:1 (CT3), (c) concurrent strength and endurance training ratio 1:1 (CT1), or (d) no training (CON). Strength training was conducted using whole-body multijoint exercises, whereas endurance training consisted of treadmill running. Assessments of maximal strength, lower-body power, and endocrine factors were conducted pretraining and after 3 and 6 weeks. After the intervention, ST and CT3 elicited similar increases in lower-body strength; furthermore, ST resulted in greater increases than CT1 and CON (all p ≤ 0.05). All training conditions resulted in similar increases in upper-body strength after training. The ST group observed greater increases in lower-body power than all other conditions (all p ≤ 0.05). After the final training session, CT1 elicited greater increases in cortisol than ST (p = 0.008). When implemented as part of a concurrent training regimen, higher volumes of endurance training result in the inhibition of lower-body strength, whereas low volumes do not. Lower-body power was attenuated by high and low frequencies of endurance training. Higher frequencies of endurance training resulted in increased cortisol responses to training. These data suggest that if strength development is the primary focus of a training intervention, frequency of endurance training should remain low.
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Affiliation(s)
- Thomas W Jones
- 1ASPIRE, Academy for Sports Excellence, Doha, Qatar;2Department of Sport, Exercise, and Rehabilitation, Northumbria University, Newcastle upon Tyne, United Kingdom;3Water Research Group, School of Environmental Sciences and Development, North West University, Potchefstroom, South Africa; and4English Institute of Sport, Sportcity, Manchester, United Kingdom
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Filaire E, Lac G, Pequignot JM. Biological, Hormonal, and Psychological Parameters in Professional Soccer Players Throughout a Competitive Season. Percept Mot Skills 2016; 97:1061-72. [PMID: 15002848 DOI: 10.2466/pms.2003.97.3f.1061] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
We examined changes in the haematological, metabolic, immunological, hormonal, and psychological fields using selected variables in 20 professional soccer players, over the course of a competitive season. The team performance was assessed by computing the winning percentage. A symptom checklist was used to assess the severity of upper respiratory tract infections. A high-intensity training programme induced a significant increase in cortisol and uric acid concentrations. Despite lower glutamine concentrations than the normal range throughout the study, infection occurred only in two of the soccer players. Moreover, the levels of immunological factors IgA, IgG, and IgM, and the haematological parameters were unaltered. Subsequent decreased performance coincided with changes in specific mood states of the team. Our results show some alterations on the metabolic, hormonal, and psychological variables over the five fields studied, suggesting that combined psychological and physiological changes during training are of primary interest to monitor the training stress in relation to performance in team sport.
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Affiliation(s)
- Edith Filaire
- Laboratoire de la Performance Motrice, Bâtiment Biologie, Les Cézeaux, Université Blaise Pascal, France.
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31
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Puggina EF, Tourinho Filho H, Machado DRL, Barbanti VJ. Efeitos do treinamento e de uma prova de triathlon em indicadores de lesão muscular e inflamação. REVISTA BRASILEIRA DE CIÊNCIAS DO ESPORTE 2016. [DOI: 10.1016/j.rbce.2015.10.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Shariat A, Kargarfard M, Danaee M, Bahri Mohd Tamrin S. Intensive resistance exercise and circadian salivary testosterone concentrations among young male recreational lifters. J Strength Cond Res 2016; 29:151-8. [PMID: 25051005 DOI: 10.1519/jsc.0000000000000632] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Strength and morphological adaptations to resistance exercise are mediated in part by anabolic hormones such as testosterone, yet the time course of variability in circadian hormone concentrations is not well characterized. This study, investigated how the circadian rhythm of salivary testosterone is altered by resistance exercise in young men. Twenty healthy young male recreational lifters (age, 18.0 ± 1.3 years) with 2 years of experience in weightlifting were recruited. A randomized controlled trial was conducted, and subjects were randomly assigned to either the resistance exercise group (n = 10), who completed a series of resistance exercise (3 times a week, in the afternoon, 6-7 repetitions, at 85% of 1 repetition maximum for 3 weeks), or a control group (n = 10), who did not exercise during the 3 weeks. Before and after the study, an unstimulated saliva sample (2 ml) was taken every 2 hours for a maximum of 16 hours during each day. A significant decrease was observed in the resistance exercise (44.2%, p = 0.001) and control group (46.1%, p = 0.001) for salivary testosterone at each time point compared with baseline (p = 0.001). There was also no significant difference between the exercise and resting conditions in both groups for salivary testosterone (p > 0.05), except a significantly higher increase by 38.4% vs. -0.02% (p = 0.001), at 1730 hours during exercise sessions in the resistance exercise group compared with the control group. Resistance exercise has no noteworthy effect on circadian secretion of salivary testosterone throughout the 16 waking hours. These results indicate that athletes can undertake resistance exercise in either the morning or afternoon with the knowledge that a similar testosterone response can be expected regardless of the time of day.
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Affiliation(s)
- Ardalan Shariat
- 1Department of Sports Science, Faculty of Educational Studies, University Putra Malaysia, Serdang, Malaysia; 2Department of Environmental and Occupational Health, Faculty of Medicine and Health Sciences, University Putra Malaysia, Serdang, Malaysia; 3Department of Exercise Physiology, Faculty of Physical Education and Sport Sciences, University of Isfahan, Isfahan, Iran; and 4Department of Biotechnology, Faculty of Agriculture, Roudehen Branch, Islamic Azad University, Roudehen, Iran
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33
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Budnar RG, Duplanty AA, Hill DW, McFarlin BK, Vingren JL. The Acute Hormonal Response to the Kettlebell Swing Exercise. J Strength Cond Res 2014; 28:2793-800. [DOI: 10.1519/jsc.0000000000000474] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Al-Asmakh M, Stukenborg JB, Reda A, Anuar F, Strand ML, Hedin L, Pettersson S, Söder O. The gut microbiota and developmental programming of the testis in mice. PLoS One 2014; 9:e103809. [PMID: 25118984 PMCID: PMC4132106 DOI: 10.1371/journal.pone.0103809] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Accepted: 07/03/2014] [Indexed: 01/15/2023] Open
Abstract
Nutrients and environmental chemicals, including endocrine disruptors, have been incriminated in the current increase in male reproductive dysfunction, but the underlying mechanisms remain unknown. The gastrointestinal tract represents the largest surface area exposed to our environment and thereby plays a key role in connection with exposure of internal organs to exogenous factors. In this context the gut microbiome (all bacteria and their metabolites) have been shown to be important contributors to body physiology including metabolism, cognitive functions and immunity. Pivotal to male reproduction is a proper development of the testis, including the formation of the blood-testis barrier (BTB) that encapsulates and protects germ cells from stress induced environmental cues, e.g. pathogenic organisms and xenobiotics. Here we used specific pathogen free (SPF) mice and germ-free (GF) mice to explore whether gut microbiota and/or their metabolites can influence testis development and regulation of BTB. Lumen formation in the seminiferous tubules, which coincides with the development of the BTB was delayed in the testes of GF mice at 16 days postpartum. In addition, perfusion experiments (Evans blue) demonstrated increased BTB permeability in these same mice. Reduced expressions of occludin, ZO-2 and E-cadherin in GF testis suggested that the microbiota modulated BTB permeability by regulation of cell-cell adhesion. Interestingly, exposure of GF mice to Clostridium Tyrobutyricum (CBUT), which secrete high levels of butyrate, restored the integrity of the BTB and normalized the levels of cell adhesion proteins. Moreover, the GF mice exhibited lower serum levels of gonadotropins (LH and FSH) than the SPF group. In addition, the intratesticular content of testosterone was lower in GF compared to SPF or CBUT animals. Thus, the gut microbiome can modulate the permeability of the BTB and might play a role in the regulation of endocrine functions of the testis.
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Affiliation(s)
- Maha Al-Asmakh
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
- Department of Biomedical Science, College of Arts and Sciences, Qatar University, Doha, Qatar
| | - Jan-Bernd Stukenborg
- Department of Women's and Children's Health, Paediatric Endocrinology Unit, Karolinska Institutet and University Hospital, Stockholm, Sweden
| | - Ahmed Reda
- Department of Women's and Children's Health, Paediatric Endocrinology Unit, Karolinska Institutet and University Hospital, Stockholm, Sweden
| | - Farhana Anuar
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Mona-Lisa Strand
- Department of Women's and Children's Health, Paediatric Endocrinology Unit, Karolinska Institutet and University Hospital, Stockholm, Sweden
| | - Lars Hedin
- Sidra Medical and Research Center, Division of Clinical Epidemiology, Doha, Qatar
| | - Sven Pettersson
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
- LKC School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - Olle Söder
- Department of Women's and Children's Health, Paediatric Endocrinology Unit, Karolinska Institutet and University Hospital, Stockholm, Sweden
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35
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Helms ER, Aragon AA, Fitschen PJ. Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation. J Int Soc Sports Nutr 2014; 11:20. [PMID: 24864135 PMCID: PMC4033492 DOI: 10.1186/1550-2783-11-20] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2013] [Accepted: 04/29/2014] [Indexed: 12/19/2022] Open
Abstract
The popularity of natural bodybuilding is increasing; however, evidence-based recommendations for it are lacking. This paper reviewed the scientific literature relevant to competition preparation on nutrition and supplementation, resulting in the following recommendations. Caloric intake should be set at a level that results in bodyweight losses of approximately 0.5 to 1%/wk to maximize muscle retention. Within this caloric intake, most but not all bodybuilders will respond best to consuming 2.3-3.1 g/kg of lean body mass per day of protein, 15-30% of calories from fat, and the reminder of calories from carbohydrate. Eating three to six meals per day with a meal containing 0.4-0.5 g/kg bodyweight of protein prior and subsequent to resistance training likely maximizes any theoretical benefits of nutrient timing and frequency. However, alterations in nutrient timing and frequency appear to have little effect on fat loss or lean mass retention. Among popular supplements, creatine monohydrate, caffeine and beta-alanine appear to have beneficial effects relevant to contest preparation, however others do not or warrant further study. The practice of dehydration and electrolyte manipulation in the final days and hours prior to competition can be dangerous, and may not improve appearance. Increasing carbohydrate intake at the end of preparation has a theoretical rationale to improve appearance, however it is understudied. Thus, if carbohydrate loading is pursued it should be practiced prior to competition and its benefit assessed individually. Finally, competitors should be aware of the increased risk of developing eating and body image disorders in aesthetic sport and therefore should have access to the appropriate mental health professionals.
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Affiliation(s)
- Eric R Helms
- Sport Performance Research in New Zealand (SPRINZ) at AUT Millennium Institute, AUT University, 17 Antares Place, Mairangi Bay, Auckland 0632, New Zealand
| | | | - Peter J Fitschen
- Division of Nutritional Sciences, University of Illinois, Urbana, IL, USA
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Marceau K, Ruttle PL, Shirtcliff EA, Essex MJ, Susman EJ. Developmental and contextual considerations for adrenal and gonadal hormone functioning during adolescence: Implications for adolescent mental health. Dev Psychobiol 2014; 57:742-68. [PMID: 24729154 DOI: 10.1002/dev.21214] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Accepted: 03/03/2014] [Indexed: 12/13/2022]
Abstract
Substantial research has implicated the hypothalamic-pituitary-adrenal (HPA) and hypothalamic-pituitary-gonadal (HPG) axes independently in adolescent mental health problems, though this literature remains largely inconclusive. Given the cross-talk between the HPA and HPG axes and their increased activation in adolescence, a dual-axis approach that examines both axes simultaneously is proposed to predict the emergence and persistence of adolescent mental health problems. After briefly orienting readers to HPA and HPG axis functioning, we review the literature examining associations between hormone levels and changes with behavior during adolescence. Then, we provide a review of the literature supporting examination of both axes simultaneously and present the limited research that has taken a dual-axis approach. We propose future directions including consideration of between-person and within-person approaches to address questions of correlated changes in HPA and HPG hormones. Potential moderators are considered to increase understanding of the nuanced hormone-behavior associations during key developmental transitions.
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Affiliation(s)
- Kristine Marceau
- The Pennsylvania State University, University Park, PA. .,Brown University, Center for Alcohol and Addiction Studies, Providence, RI. .,Department of Psychiatry, Rhode Island Hospital, Providence, RI.
| | - Paula L Ruttle
- Department of Psychiatry, School of Medicine and Public Health, University of Wisconsin, Madison, WI
| | - Elizabeth A Shirtcliff
- Iowa State University, Department of Human Development and Family Studies, New Orleans, LA
| | - Marilyn J Essex
- Department of Psychiatry, School of Medicine and Public Health, University of Wisconsin, Madison, WI
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Gyulai G, Rácz L, Di Giminiani R, Tihanyi J. Effect of whole body vibration applied on upper extremity muscles. ACTA ACUST UNITED AC 2014; 100:37-47. [PMID: 23232701 DOI: 10.1556/aphysiol.99.2012.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The acute residual effect of whole body vibration (WBV) on upper extremity muscles and testosterone secretion was studied. Eight highly (G1), nine moderately trained gymnasts (G2) and seven physically active persons (CG) were recruited for the investigation. The intervention occurred in push-up position with the elbow flexed at 90°. G1 and G2 received 30 s, 30 Hz and 6 mm amplitude vibration repeated five times. Subjects were tested before and after one and ten minutes intervention in push-up movement. Contact time (Tc), fly time (Tf), TF/Tc ratio and impulse was measured from the ground reaction force-time curves recorded during self-selected (SSRM) and full range of motion (FRM). Testosterone level in urine was also determined. Tf increased significantly in SSRM for G1 and decreased in SSRM and FRM for G2. Tf/Tc ratio in FRM and impulse in SSRM increased significantly for G1 only. No significant alteration in testosterone level was observed. We concluded that WBV is a reasonable training modality for influencing dynamic work of upper extremity muscle, but the reaction to WBV is training and individual dependent. It seems that WBV do not influence dynamic work through increased testosterone secretion because of the relatively low mass of the involved muscles.
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Affiliation(s)
- G Gyulai
- Semmelweis University Department of Gymnastic, RG, Dance and Aerobic, Faculty of Physical Education and Sport Sciences Budapest Hungary
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Marceau K, Shirtcliff EA, Hastings P, Klimes-Dougan B, Zahn-Waxler C, Dorn L, Susman EJ. Within-adolescent coupled changes in cortisol with DHEA and testosterone in response to three stressors during adolescence. Psychoneuroendocrinology 2014; 41:33-45. [PMID: 24495606 PMCID: PMC3938090 DOI: 10.1016/j.psyneuen.2013.12.002] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 12/03/2013] [Accepted: 12/04/2013] [Indexed: 10/25/2022]
Abstract
It is hypothesized that hypothalamic-pituitary-adrenal and hypothalamic-pituitary-gonadal axes function together to maintain adaptive functioning during stressful situations differently in adolescence than the characteristic inverse relations found in adulthood. We examined within-person correlated changes (coupling) in cortisol, DHEA and testosterone in response to parent-adolescent conflict discussion, social performance, and venipuncture paradigms. Data are derived from two samples of boys and girls from the Northeastern US (213 adolescents aged 11-16, M=13.7, SD=1.5 years; 108 adolescents aged 9-14, M=11.99, SD=1.55) using different biological sampling vehicles (saliva and blood). Results consistently show that across samples, vehicles, and contexts, cortisol and DHEA and cortisol and testosterone are positively coupled in response to environmental stimuli. Findings underscore the importance of considering the effects of multiple hormones together in order to further our understanding of the biological underpinnings of behavior, especially during adolescence, as adolescence is a developmental transition period that may be qualitatively different from adulthood in terms of hormone functioning.
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Affiliation(s)
- Kristine Marceau
- The Pennsylvania State University, United States; Division of Behavior Genetics, Rhode Island Hospital Department of Psychiatry, United States; Brown University Center for Alcohol and Addiction Studies, United States.
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West DJ, Cunningham DJ, Finn CV, Scott PM, Crewther BT, Cook CJ, Kilduff LP. The metabolic, hormonal, biochemical, and neuromuscular function responses to a backward sled drag training session. J Strength Cond Res 2013; 28:265-72. [PMID: 23575361 DOI: 10.1519/jsc.0b013e3182948110] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We examined the metabolic, hormonal, biochemical, and neuromuscular function (NMF) responses to a backward sled drag training session (STS) in strength-trained men (n = 11). After baseline collection of saliva (testosterone and cortisol), whole blood (lactate and creatine kinase [CK]), and countermovement jumps (peak power output), participants completed 5 sets of 2 × 20-m (30 second-recovery between drags and 120 second-recovery between sets) maximal backward sled drags (loaded with 75% body mass). Participants were retested immediately, 15 minutes, 1, 3, and 24 hours after STS. Peak power output decreased after STS (baseline, 4,445 ± 705 vs. 0 minute, 3,464 ± 819 W; p = 0.001) and remained below baseline until recovering at both the 3- and 24-hour time points. No changes in CK levels were seen at any time point after STS. Blood lactate increased immediately after STS (baseline, 1.7 ± 0.5 vs. 0 minute, 12.4 ± 2.6 mmol·L-1; p = 0.001) and remained elevated at 60 minutes (3.8 ± 1.9 mmol·L-1; p = 0.004) before returning to baseline at 3 and 24 hours. Testosterone peaked at 15 minutes post (baseline, 158 ± 45 vs. 15 minutes, 217 ± 49 pg·ml-1; p < 0.001) before decreasing below baseline at the 3-hour time point (119 ± 34 pg·ml-1; p = 0.008), but then increased again above baseline at 24 hours (187 ± 56 pg·ml-1; p = 0.04). Cortisol tended to increase at 15 minutes (baseline, 3.4 ± 1.8 vs. 15 minutes, 5.2 ± 2.7 ng·ml-1; p = 0.07) before declining below baseline at 3 hours (1.64 ± 0.93 ng·ml-1; p = 0.012) and returning to baseline concentrations at 24 hours. In conclusion, sled dragging provides an effective metabolic stimulus, with NMF restored after ≤3 hours of recovery. Characterizing the recovery time course after sled training may aid in athlete training program design.
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Affiliation(s)
- Daniel J West
- 1Department of Sport and Exercise Science, School of Life Science, Northumbria University, Newcastle upon Tyne, United Kingdom; 2Health and Sport Portfolio, College of Engineering, Swansea University, Swansea, United Kingdom; 3Hamlyn Center, Institute of Global Health Innovation, Imperial College, London, United Kingdom; and 4Sport and Exercise Science, University of Bath, Bath, United Kingdom
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40
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Macaluso F, Barone R, Catanese P, Carini F, Rizzuto L, Farina F, Di Felice V. Do fat supplements increase physical performance? Nutrients 2013; 5:509-24. [PMID: 23434906 PMCID: PMC3635209 DOI: 10.3390/nu5020509] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Revised: 01/07/2013] [Accepted: 01/31/2013] [Indexed: 01/07/2023] Open
Abstract
Fish oil and conjugated linoleic acid (CLA) belong to a popular class of food supplements known as "fat supplements", which are claimed to reduce muscle glycogen breakdown, reduce body mass, as well as reduce muscle damage and inflammatory responses. Sport athletes consume fish oil and CLA mainly to increase lean body mass and reduce body fat. Recent evidence indicates that this kind of supplementation may have other side-effects and a new role has been identified in steroidogenensis. Preliminary findings demonstrate that fish oil and CLA may induce a physiological increase in testosterone synthesis. The aim of this review is to describe the effects of fish oil and CLA on physical performance (endurance and resistance exercise), and highlight the new results on the effects on testosterone biosynthesis. In view of these new data, we can hypothesize that fat supplements may improve the anabolic effect of exercise.
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Affiliation(s)
- Filippo Macaluso
- Department of Experimental Biomedicine and Clinical Neurosciences, University of Palermo, Palermo, Italy.
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41
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Marceau K, Dorn LD, Susman EJ. Stress and puberty-related hormone reactivity, negative emotionality, and parent--adolescent relationships. Psychoneuroendocrinology 2012; 37:1286-98. [PMID: 22284540 DOI: 10.1016/j.psyneuen.2012.01.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Revised: 01/02/2012] [Accepted: 01/03/2012] [Indexed: 11/28/2022]
Abstract
Hormone reactivity to stressors and hormones that rapidly change at puberty are hypothesized to influence moods, which may in turn affect parent-child relationship quality. The present study investigated whether reactivity of testosterone, DHEA, and cortisol in a clinic setting (venipuncture paradigm) predicted negative emotionality and family problems at Time 1 (0 months), Time 2 (6 months), and Time 3 (12 months) in a sample of 56 boys (M = 12.72, SD = 1.32 years) and 52 girls (M = 11.99, SD = 1.55 years). Reactivity of each hormone, negative emotionality, and family problems were measured at each of three laboratory visits. Testosterone reactivity at the first assessment predicted family problems one year later. DHEA stress reactivity was related to concurrent negative emotionality at six and 12 months. Cortisol reactivity did not predict negative emotionality or family problems. Reactivity of different hormones that change at puberty may play an important role in adolescent moods and family processes during puberty.
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42
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Stanton A. Hormone Replacement in Men. Integr Med (Encinitas) 2012. [DOI: 10.1016/b978-1-4377-1793-8.00034-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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43
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Hakimi M, Mohamadi MA, Ghaderi Z. The effects of glutamine supplementation on performance and hormonal responses in non-athlete male students during eight week resistance training. JOURNAL OF HUMAN SPORT AND EXERCISE 2012. [DOI: 10.4100/jhse.2012.74.05] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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Fragala MS, Kraemer WJ, Denegar CR, Maresh CM, Mastro AM, Volek JS. Neuroendocrine-immune interactions and responses to exercise. Sports Med 2011; 41:621-39. [PMID: 21780849 DOI: 10.2165/11590430-000000000-00000] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
This article reviews the interaction between the neuroendocrine and immune systems in response to exercise stress, considering gender differences. The body's response to exercise stress is a system-wide effort coordinated by the integration between the immune and the neuroendocrine systems. Although considered distinct systems, increasing evidence supports the close communication between them. Like any stressor, the body's response to exercise triggers a systematic series of neuroendocrine and immune events directed at bringing the system back to a state of homeostasis. Physical exercise presents a unique physiological stress where the neuroendocrine and immune systems contribute to accommodating the increase in physiological demands. These systems of the body also adapt to chronic overload, or exercise training. Such adaptations alleviate the magnitude of subsequent stress or minimize the exercise challenge to within homeostatic limits. This adaptive capacity of collaborating systems resembles the acquired, or adaptive, branch of the immune system, characterized by the memory capacity of the cells involved. Specific to the adaptive immune response, once a specific antigen is encountered, memory cells, or lymphocytes, mount a response that reduces the magnitude of the immune response to subsequent encounters of the same stress. In each case, the endocrine response to physical exercise and the adaptive branch of the immune system share the ability to adapt to a stressful encounter. Moreover, each of these systemic responses to stress is influenced by gender. In both the neuroendocrine responses to exercise and the adaptive (B lymphocyte) immune response, gender differences have been attributed to the 'protective' effects of estrogens. Thus, this review will create a paradigm to explain the neuroendocrine communication with leukocytes during exercise by reviewing (i) endocrine and immune interactions; (ii) endocrine and immune systems response to physiological stress; and (iii) gender differences (and the role of estrogen) in both endocrine response to physiological stress and adaptive immune response.
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Affiliation(s)
- Maren S Fragala
- Human Performance Laboratory, Department of Kinesiology, University of Connecticut, Storrs, CT 06269-1110, USA
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45
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Effects of very short rest periods on testosterone to cortisol ratio during heavy resistance exercise in men. ACTA ACUST UNITED AC 2011. [DOI: 10.1016/j.apunts.2011.03.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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46
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The Effects of Whey Protein Supplementation on Performance and Hormonal Adaptations Following Resistance Training in Novice Men. BALTIC JOURNAL OF HEALTH AND PHYSICAL ACTIVITY 2011. [DOI: 10.2478/v10131-011-0008-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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47
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Vingren JL, Kraemer WJ, Ratamess NA, Anderson JM, Volek JS, Maresh CM. Testosterone Physiology in Resistance Exercise and Training. Sports Med 2010; 40:1037-53. [PMID: 21058750 DOI: 10.2165/11536910-000000000-00000] [Citation(s) in RCA: 238] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Jakob L Vingren
- Applied Physiology Laboratories, Department of Kinesiology, Health Promotion and Recreation, University of North Texas, Denton, Texas, USA
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Fry AC, Lohnes CA. Acute testosterone and cortisol responses to high power resistance exercise. ACTA ACUST UNITED AC 2010. [DOI: 10.1134/s0362119710040110] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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49
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50
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Knechtle B, Wirth A, Knechtle P, Rosemann T. Training Volume and Personal Best Time in Marathon, Not Anthropometric Parameters, are Associated with Performance in Male 100-KM Ultrarunners. J Strength Cond Res 2010; 24:604-9. [DOI: 10.1519/jsc.0b013e3181c7b406] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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