Effect of zinc and selenium supplementation on serum testosterone and plasma lactate in cyclist after an exhaustive exercise bout

Do "testosterone boosters" really increase serum total testosterone? A systematic review

Testosterone boosters are heavily marketed on social media and marketplaces to men with claims to significantly increase testosterone. Lax industry regulation has allowed sales of supplements to thrive in the absence of verification of their purported benefits. Our primary objective was to systematically review all data published in the last two decades on testosterone boosters and determine their efficacy. Our outcome of interest was total testosterone increase versus placebo in four different populations: male athletes, men with late-onset hypogonadism infertile men and healthy men. Following search and screening, 52 studies were included in our review, relating to 27 proposed testosterone boosters: 10 studies of cholecalciferol; 5 zinc/magnesium; 4 Tribulus terrestris and creatine; 3 Eurycoma longifolia and Withania somnifera; 2 betaine, D-aspartic acid, Lepidium meyenii and isoflavones; while the remainder were single reports. Our findings indicate that most fail to increase total testosterone. The exceptions were β-hydroxy β-methylbutyrate and betaine, which can be considered effective for male athletes. Eurycoma longifolia, a blend of Punica granatum fruit rind and Theobroma cacao seed extracts (Tesnor™) and purified Shilajit extract (PrimaVie™) can be considered possibly effective for men with late-onset hypogonadism; Eurycoma longifolia and Withania somnifera possibly effective for healthy men; and a non-hormonal aromatase inhibitor (Novadex XT™) possibly effective for male athletes.

Effect of Selenium Supplementation on Biochemical Markers of Women with Polycystic Ovarian Syndrome: A Systematic Review

Polycystic ovary syndrome (PCOS) is a widespread endocrine disorder among fertile women and may be induced by nutritional deficiencies. In this study, we assess the impact of selenium supplementation (SS) on biochemical markers in women with PCOS. To gather relevant literature, we searched the Web of Science, Cochrane Library, Scopus, Embase, and MEDLINE databases from inception up to July 24, 2022. Subsequently, we included all published full-text randomized clinical trials examining the effects of SS versus placebo on biochemical changes in women with PCOS. Review Manager 5.3 was used to collect and analyze data and assess the risk of bias. Seven articles, comprising 413 women, were ultimately involved in the study. According to the results, SS could increase the level of quantitative insulin sensitivity check index [standardized mean difference (SMD)=0.34, 95% confidence interval (CI)=0.04∼0.65], total antioxidant capacity (SMD=0.89 mmol/L, 95% CI=0.52∼1.26), and glutathione (SMD=1.00 μmol/L, 95% CI=0.22∼1.78). Conversely, SS could decrease triglyceride, cholesterol, fasting plasma glucose, insulin, and the homeostasis model of assessment-insulin resistance levels compared with the placebo. Furthermore, there were no significant differences regarding sex hormone-binding globulin level, testosterone level, malondialdehyde, and body mass index between the two groups. In addition, the results suggest that SS improves biochemical markers in women with PCOS and thus is recommended for treating biochemical disorders among these women in addition to standard treatment.

Micronutrient supplement intakes among collegiate and masters athletes: A cross-sectional study

Objective

In our cross-sectional study, we evaluated micronutrient supplementation intake among Collegiate and Masters Athletes.

Methods

We conducted a cross-sectional study to assess micronutrient supplementation consumption in Collegiate and Masters Athletes, comparing sex and sport classification within each respective group. Micronutrient supplement consumption data were measured using a Food Frequency Questionnaire. A two-way analysis of variance was used to explore the differences among Collegiate and Masters Athletes' supplement intakes of the following vitamins and minerals: vitamins A, B6, B12, C, E, D, and calcium, folate, iron, magnesium niacin, riboflavin, selenium, thiamine, and zinc. When significant differences were found, a Bonferroni post hoc test was performed to identify specific group differences. The significance level was set a priori at p < 0.05.

Results

A total of 198 athletes (105 females and 93 males) were included in the study. Participants were 36.16 ± 12.33 years of age. Collegiate male athletes had significantly greater vitamin A [1,090.51 ± 154.72 vs. 473.93 ± 233.18 mg retinol activity equivalents (RAE)/day] (p < 0.036), folate [337.14 ± 44.79 vs. 148.67 ± 67.50 mcg dietary folate equivalents (DFE)/day] (p < 0.027), and magnesium (65.35 ± 8.28 vs. 31.28 ± 12.48 mg/day) (p < 0.031) intakes compared to Collegiate female athletes. Collegiate CrossFit Athletes (940.71 ± 157.54 mg/day) had a significantly greater vitamin C intake compared to Collegiate General Athletes (156.34 ± 67.79 mg/day) (p < 0.005), Collegiate Triathletes (88.57 ± 148.53 mg/day) (p < 0.027), Collegiate Resistance Training Athletes (74.28 ± 143.81 mg/day) (p < 0.020), and Collegiate Powerlifters (175.71 ± 128.63 mg/day) (p < 0.044). Masters females had significantly greater calcium intakes compared to Masters males (494.09 ± 65.73 vs.187.89 ± 77.23 mg/day, respectively) (p < 0.002). Collegiate Runners (41.35 ± 6.53 mg/day) had a significantly greater iron intake compared to Collegiate Powerlifters (4.50 ± 6.53 mg/day) (p < 0.024). Masters Swimmers (61.43 ± 12.10 mg/day) had significantly greater iron intakes compared to Masters General Athletes (13.97 ± 3.56 mg/day) (p < 0.014), Masters Runners (17.74 ± 2.32 mg/day) (p < 0.03), Masters Triathletes (11.95 ± 3.73 mg/day) (p < 0.008), Masters CrossFit Athletes (15.93 ± 5.36 mg/day) (p < 0.043), Masters Rowers (9.10 ± 3.36 mg/day) (p < 0.003), and Masters Cyclists (1.71 ± 9.88 mg/day) (p < 0.011). Masters Powerlifters (47.14 ± 9.65 mg/day) had significantly greater zinc intakes compared to Masters General Athletes (9.57 ± 2.84 mg/day) (p < 0.015), Masters Runners (10.67 ± 1.85 mg/day) (p < 0.017), Masters Triathletes (10.24 ± 2.98 mg/day) (p < 0.020), Masters Rowers (9.33 ± 2.68 mg/day) (p < 0.013), and Masters Cyclists (1.43 ± 7.88 mg/day) (p < 0.019). There were no other significant differences among the other micronutrient supplement intakes between the sexes or among the sport classification.

Conclusion

We reported significant differences among female and male Collegiate and Masters Athletes. Additionally, we reported significant differences among Collegiate and Masters Athletes sport classifications. Further research should examine both dietary and micronutrient supplement intake among Collegiate and Masters Athletes to examine the extent that athletes exceed the Recommended Dietary Allowances (RDA), and the potential effects on health and performance.

Inhibitory effects of zinc chloride (ZnCl2), n-acetyl-L-cysteine (NAC), and calcium/calmodulin dependent protein kinase II inhibitor (KN93) on Cd2+-induced abnormal cell morphology and membrane permeability

Cadmium (Cd) could reduce abnormal cell morphology and membrane permeability, however, there are few studies on the detoxification of Cd-reduced cell membrane toxicity. In the present study, we firstly studied the effects of zinc chloride (ZnCl₂), n-acetyl-L-cysteine (NAC), and calcium/calmodulin dependent protein kinase II inhibitor (KN93) on cell membrane permeability, respectively; then, we studied the inhibitory effects of ZnCl₂, NAC, and KN93 on Cd²⁺-induced abnormal cell membrane permeability by scanning electrochemical microscopy (SECM) scanning imaging, transverse scanning curve and DPV technology. Our results showed that 10 μmol·L^-1 ZnCl₂, 0.5 mmol·L^-1 NAC and 5 μmol·L^-1 KN93 could significantly improve the activity of MCF-7 cells, while did not destroy the cell morphology and membrane permeability. 0.5 mmol·L^-1 NAC and 5 μmol·L^-1 KN93 could significantly inhibit the effects of Cd²⁺ on the morphology and membrane permeability of MCF-7 cells (p < 0.01). 10 μmol·L^-1 ZnCl₂ could significantly inhibit the effect of Cd on the membrane permeability of MCF-7 cells, however, it cannot completely eliminate the morphological changes of MCF-7 cells caused by Cd²⁺. The results of cell activity experiment showed that 10 μmol·L^-1 ZnCl₂, 0.5 mmol·L^-1 NAC and 5 μmol·L^-1 KN93 could inhibit the effect of Cd²⁺ on the activity of MCF-7 cells. By comparing the inhibitory effects of ZnCl₂, NAC and KN93 on Cd²⁺- induced cytotoxicity, 5 μmol·L^-1 KN93 had the robust effect on the maintenance of MCF-7 cell morphology and cell membrane integrity. Our research provided evidence on Zn supplement, NAC as antioxidant drugs, and KN93 as special inhibitor for the detoxification of Cd²⁺-reduced abnormal cell morphology and membrane permeability.

Analysis of Intracellular and Extracellular Selenium Concentrations: Differences According to Training Level

Trace mineral element concentrations are under homeostatic control. Selenium (Se) is a very important micronutrient for the antioxidant and immune system. Se metabolism could be modified due to physical training. This research aimed to analyze the extracellular (plasma, urine and serum) and intracellular (platelets and erythrocytes) concentrations of Se in athletes and to compare it with subjects with low levels of physical training. Forty young men divided into a control group (CG; n = 20; 19.25 ± 0.39 years) and a training group (TG; n = 20; 18.15 ± 0.27 years) participated in this study. The TG was formed by semi-professional soccer players. The analysis of Se was determined by inductively coupled plasma mass spectrometry. The TG obtained higher values of maximum oxygen consumption and muscle percentage (p < 0.05). The TG showed reduced absolute (p < 0.01) and relative (p < 0.05) Se concentrations in erythrocytes and platelets in comparison to CG. Trace element assessments should not be limited only to extracellular compartments as there could be deficiencies at the intracellular level.

Manipulation of Dietary Intake on Changes in Circulating Testosterone Concentrations

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.

Bioaccessibility and Bioavailability of Minerals in Relation to a Healthy Gut Microbiome

Adequate amounts of a wide range of micronutrients are needed by body tissues to maintain health. Dietary intake must be sufficient to meet these micronutrient requirements. Mineral deficiency does not seem to be the result of a physically active life or of athletic training but is more likely to arise from disturbances in the quality and quantity of ingested food. The lack of some minerals in the body appears to be symbolic of the modern era reflecting either the excessive intake of empty calories or a negative energy balance from drastic weight-loss diets. Several animal studies provide convincing evidence for an association between dietary micronutrient availability and microbial composition in the gut. However, the influence of human gut microbiota on the bioaccessibility and bioavailability of trace elements in human food has rarely been studied. Bacteria play a role by effecting mineral bioavailability and bioaccessibility, which are further increased through the fermentation of cereals and the soaking and germination of crops. Moreover, probiotics have a positive effect on iron, calcium, selenium, and zinc in relation to gut microbiome composition and metabolism. The current literature reveals the beneficial effects of bacteria on mineral bioaccessibility and bioavailability in supporting both the human gut microbiome and overall health. This review focuses on interactions between the gut microbiota and several minerals in sport nutrition, as related to a physically active lifestyle.

Acute effect of HIIT on testosterone and cortisol levels in healthy individuals: A systematic review and meta-analysis

To determine the acute effect of a single high-intensity interval training (HIIT) session on testosterone and cortisol levels in healthy individuals, a systematic search of studies was conducted in MEDLINE and Web of Science databases from inception to February 2020. Meta-analyses were performed to establish the acute effect of HIIT on testosterone and cortisol levels immediately after a single HIIT session; after 30 min and 60 min (primary outcomes); and after 120 min, 180 min, and 24 h (secondary outcomes, only for pre-post intervention groups). Potential effect-size modifiers were assessed by meta-regression analyses and analyses of variance. Study quality was assessed using the Cochrane's risk of bias tool and the Physiotherapy Evidence Database scale. The meta-analyses of 10 controlled studies (213 participants) and 50 pre-post intervention groups (677 participants) revealed a significant increase in testosterone immediately after a single HIIT session (d = 0.92 and 0.52, respectively), which disappeared after 30 min (d = 0.18 and -0.04), and returned to baseline values after 60 min (d = -0.37 and -0.16). Significant increases of cortisol were found immediately after (d = 2.17 and 0.64), after 30 min (d = 1.62 and 0.67) and 60 min (d = 1.32 and 0.27). Testosterone and cortisol levels decreased significantly after 120 min (d = -0.48 and -0.95, respectively) and 180 min (d = -0.29 and -1.08), and returned to baseline values after 24 h (d = 0.14 and -0.02). HIIT components and participant's characteristics seem to moderate the effect sizes. In conclusion, testosterone and cortisol increase immediately after a single HIIT session, then drop below baseline levels, and finally return to baseline values after 24 h. This meta-analysis provides a better understanding of the acute endocrine response to a single HIIT session, which would certainly be valuable for both clinicians and coaches in the prescription of exercise programs to improve health and performance. Testosterone and cortisol may be used as sensitive biomarkers to monitor the anabolic and catabolic response to HIIT.

Testosterone Boosters Intake in Athletes: Current Evidence and Further Directions

“Testosterone boosters” (TB)—are supplements that are claimed to increase testosterone levels in the human body. While the consumption of TB may be popular among athletes, there is insufficient evidence both about the safety and the real efficacy of TB. In our review, we searched MEDLINE/PubMed and Cochrane Library for studies on the effects of 15 substances that are claimed to increase testosterone levels Anacyclus pyrethrum; Bulbine natalensis; Epimedium (horny goat weed); L-arginine; L-carnitine; magnesium; Mucuna pruriens; pantothenic acid; selenium; shilajit Eurycoma longifolia (Tongkat Ali); Serenoa repens (saw palmetto); boron; Withania somnifera (ashwagandha); and Trigonella foenum-graecum (fenugreek) in athletes and healthy adults under 55 years of age. We found such studies regarding 10 out of 15 substances: L-arginine (3 studies); L-carnitine (2); magnesium (1); selenium (2); shilajit (1); Tongkat Ali (2); Serenoa repens (1); boron (3); ashwagandha root (2); and fenugreek (7). Many of them fail to prove the efficacy of these substances to increase testosterone levels. Tongkat Ali, ashwagandha, and fenugreek were the substances with the strongest evidence. The positive effect of magnesium and shilajit on testosterone concentration was shown in single studies. Conflicting data found that L-arginine, L-carnitine, Serenoa repens, selenium and boron do not appear to increase testosterone levels. There are almost no data on the safety profile of various TB components; however, certain TB components may be linked to coagulation, and pancreatic and hepatic disorders. Based on the review, the authors conclude that at present TB cannot be recommended for use by athletes due to insufficient data on their efficacy and safety.

Use of medicinal doses of zinc as a safe and efficient coadjutant in the treatment of male hypogonadism

Hypogonadism affects an extensive part of the male population, especially among the elderly. The quest for treatment regarding low levels of serum testosterone and male infertility has, therefore, worldwide relevance. Zinc has important biological actions insofar as the male reproductive physiology and endocrine system. In general, a common and safe recommendation for zinc in the treatment of male hypogonadism is 220 mg of zinc sulfate (equivalent to 50 mg of elemental zinc) twice a day, over one to four months. Additionally, it may be further required to extend, both the treatment, dose and daily fractionation of this mineral. Albeit medicinal doses of zinc may increase total testosterone and improve sperm count, the current body of evidence does not suggest broad recommendations regarding the use of zinc for all types of hypogonadism. In many cases, the use of zinc supplements is insufficient, with the use of surgery and drugs being required for an effective treatment.

The Role of Selenium Mineral Trace Element in Exercise: Antioxidant Defense System, Muscle Performance, Hormone Response, and Athletic Performance. A Systematic Review

Exercise overproduces oxygen reactive species (ROS) and eventually exceeds the body’s antioxidant capacity to neutralize them. The ROS produce damaging effects on the cell membrane and contribute to skeletal muscle damage. Selenium (Se), a natural mineral trace element, is an essential component of selenoproteins that plays an important role in antioxidant defense. The activity of the enzyme glutathione peroxidase (GPx), a highly-efficient antioxidant enzyme, is closely dependent on the presence of Se. These properties of Se may be potentially applicable to improve athletic performance and training recovery. We systematically searched for published studies to evaluate the effectiveness of Se supplementation on antioxidant defense system, muscle performance, hormone response, and athletic performance among physically active individuals. We used the Preferred Reporting Elements for Systematic Reviews and Meta-Analysis (PRISMA) guidelines and searched in SCOPUS, Web of Science (WOS), and PubMed databases to identify published studies until March 2020. The systematic review incorporated original studies with randomized controlled crossover or parallel design in which intake of Se administered once a day was compared with the same placebo conditions. No exclusions were applied for the type of physical exercise performed, the sex, nor the age of the participants. Among 150 articles identified in the search, 6 met the criteria and were included in the systematic review. The methodological quality of the studies was evaluated using the McMaster Critical Review Form. Oral Se supplementation with 180 µg/day or 240 µg/day (selenomethionine) and 200 µg/day (Sodium Selenite), significantly decreased lipid hydroperoxide levels and increased GPx in plasma, erythrocyte, and muscle. No significant effects were observed on athletic performance, testosterone hormone levels, creatine kinase activity, and exercise training-induced adaptations on oxidative enzyme activities or on muscle fiber type myosin heavy chain expression. In addition, Se supplementation showed to have a dampening effect on the mitochondria changes in chronic and acute exercise. In summary, the use of Se supplementation has no benefits on aerobic or anaerobic athletic performance but it may prevent Se deficiencies among athletes with high-intensity and high-volume training. Optimal Se plasma levels may be important to minimize chronic exercise-induced oxidative effects and modulate the exercise effect on mitochondrial changes.

Effects of Dietary or Supplementary Micronutrients on Sex Hormones and IGF-1 in Middle and Older Age: A Systematic Review and Meta-Analysis

Observational research suggests that micronutrients may be protective for sarcopenia, a key health issue during ageing, potentially via effects on hormone synthesis and metabolism. We aimed to carry out a systematic review of RCTs investigating effects of increasing dietary or supplemental micronutrient intake on sex hormones and IGF-1 in individuals aged 45 years or older. We searched MEDLINE, EMBASE and Cochrane databases for RCTs reporting the effects of different micronutrients (vitamins A, C, D, or E; carotenoids; iron; copper; zinc; magnesium; selenium; and potassium) on sex hormones or IGF-1. Of the 26 RCTs identified, nine examined effects of vitamin D, nine of multi-nutrients, four of carotenoids, two of selenium, one of zinc, and one of vitamin E. For IGF-1 increasing vitamin D (MD: −0.53 nmol/L, 95% CI: −1.58, 0.52), multi-nutrients (MD: 0.60 nmol/L, 95% CI −1.12 to 2.33) and carotenoids (MD −1.32 nmol/L; 95% CI −2.76 to 0.11) had no significant effect on circulating concentrations. No significant effects on sex hormones of other micronutrients were found, but data were very limited. All trials had significant methodological limitations making effects of micronutrient supplementation on sex hormones unclear. Further high quality RCTs with physiological doses of micronutrients in people with low baseline intakes or circulating concentrations, using robust methodology, are required to assess effects of supplementation adequately.

The Role of Mineral and Trace Element Supplementation in Exercise and Athletic Performance: A Systematic Review

Minerals and trace elements (MTEs) are micronutrients involved in hundreds of biological processes. Deficiency in MTEs can negatively affect athletic performance. Approximately 50% of athletes have reported consuming some form of micronutrient supplement; however, there is limited data confirming their efficacy for improving performance. The aim of this study was to systematically review the role of MTEs in exercise and athletic performance. Six electronic databases and grey literature sources (MEDLINE; EMBASE; CINAHL and SportDISCUS; Web of Science and clinicaltrials.gov) were searched, in accordance with PRISMA guidelines. Results: 17,433 articles were identified and 130 experiments from 128 studies were included. Retrieved articles included Iron (n = 29), Calcium (n = 11), Magnesium, (n = 22), Phosphate (n = 17), Zinc (n = 9), Sodium (n = 15), Boron (n = 4), Selenium (n = 5), Chromium (n = 12) and multi-mineral articles (n = 5). No relevant articles were identified for Copper, Manganese, Iodine, Nickel, Fluoride or Cobalt. Only Iron and Magnesium included articles of sufficient quality to be assigned as 'strong'. Currently, there is little evidence to support the use of MTE supplementation to improve physiological markers of athletic performance, with the possible exception of Iron (in particular, biological situations) and Magnesium as these currently have the strongest quality evidence. Regardless, some MTEs may possess the potential to improve athletic performance, but more high quality research is required before support for these MTEs can be given. PROSPERO preregistered (CRD42018090502).

Supplements with purported effects on muscle mass and strength

PURPOSE

Several supplements are purported to promote muscle hypertrophy and strength gains in healthy subjects, or to prevent muscle wasting in atrophying situations (e.g., ageing or disuse periods). However, their effectiveness remains unclear.

METHODS

This review summarizes the available evidence on the beneficial impacts of several popular supplements on muscle mass or strength.

RESULTS

Among the supplements tested, nitrate and caffeine returned sufficient evidence supporting their acute beneficial effects on muscle strength, whereas the long-term consumption of creatine, protein and polyunsaturated fatty acids seems to consistently increase or preserve muscle mass and strength (evidence level A). On the other hand, mixed or unclear evidence was found for several popular supplements including branched-chain amino acids, adenosine triphosphate, citrulline, β-Hydroxy-β-methylbutyrate, minerals, most vitamins, phosphatidic acid or arginine (evidence level B), weak or scarce evidence was found for conjugated linoleic acid, glutamine, resveratrol, tribulus terrestris or ursolic acid (evidence level C), and no evidence was found for other supplements such as ornithine or α-ketoglutarate (evidence D). Of note, although most supplements appear to be safe when consumed at typical doses, some adverse events have been reported for some of them (e.g., caffeine, vitamins, α-ketoglutarate, tribulus terrestris, arginine) after large intakes, and there is insufficient evidence to determine the safety of many frequently used supplements (e.g., ornithine, conjugated linoleic acid, ursolic acid).

CONCLUSION

 In summary, despite their popularity, there is little evidence supporting the use of most supplements, and some of them have been even proven ineffective or potentially associated with adverse effects.

Effects of maternal dietary selenium (Se-enriched yeast) on testis development, testosterone level and testicular steroidogenesis-related gene expression of their male kids in Taihang Black Goats

To investigate the effects of maternal dietary selenium (Se-enriched yeast) on testis development, testosterone level and steroidogenesis-related gene expression in testis of their male kids, selected pregnant Taihang Black Goats were randomly allotted to four treatment groups. They were fed the basal gestation and lactation diets supplemented with 0 (control), 0.5, 2.0 and 4.0 mg of Se/kg DM. Thirty days after weaning, testes were collected from the kids. After the morphological development status of testis was examined, tissue samples were collected for analyzing testosterone concentration and histological parameters. Testosterone synthesis-related genes were detected using real-time PCR. Localization and quantification of androgen receptor (AR) in testis of goats were determined by immunohistochemical and western blot analysis. The results show that Se supplementation in the diet of dams led to higher (p < 0.05) testicular weight, volume, length, width, transverse and vertical grith of their male kids. Excessive Se (4.0 mg/kg) can inhibit the development of testis by decreasing testicular weight and volume. The density of spermatogenic cells and Leydig cells in the Se treatment groups was significantly (p < 0.05) higher than that in the control. Maternal dietary Se did not affect the thickness of testes, thickness of germinal epithelium and diameter of seminiferous tubule. Se supplemented in the diet of dams improved the testosterone level in testis tissue and serum, and promote the expression of testosterone-related genes. The mRNA expression of StAR, 3β-HSD and CYP11A1 was decreased with the increasing dietary Se levels of dams. Maternal dietary Se can improve the AR protein abundance in testis of their offspring. AR immunopositive product was detected in Leydig cells, peritubular myoid cells, perivascular smooth muscle cells, primary spermatocytes and spermatids. The expression of AR in spermatogenetic cells is stage specific. This study suggests that maternal dietary Se can influence the testis development and spermatogenesis of their male kids by modulating testosterone synthesis in goats. More attention should be given to the potential role of maternal nutrition in improving reproductive performance of their offspring.

Effect of Resveratrol Administration on the Element Metabolism in the Blood and Brain Tissues of Rats Subjected to Acute Swimming Exercise

The aim of the present study is to examine how resveratrol administration affects the element metabolism in the blood and brain cortex tissues of rats subjected to an acute swimming exercise. The study was carried out on Wistar-Albino-type adult male rats supplied by the Center. Group 1 is the control group. Group 2 is the swimming control group. Group 3 is the resveratrol (10 mg/kg/day) + swimming group. Group 4 is the resveratrol (10 mg/kg/day) group. Blood and brain cortex tissues were analyzed for some elements. The acute swimming exercise led to increases in the rats' serum iron, selenium, lead, cobalt, and boron levels, while the resveratrol-swimming group has increases in copper, phosphorus, and calcium values. The brain cortex tissue of the resveratrol-swimming group had significantly higher molybdenum levels than others. The results obtained in the study indicate that acute swimming exercise altered the distribution of elements in the serum to a considerable extent; however, resveratrol's affect is limited. Especially, resveratrol supplementation may have a regulatory affect on serum iron and magnesium levels.

The Effects of a Multi-Ingredient Performance Supplement on Hormonal Profiles and Body Composition in Male College Athletes

Periods of intense training can elicit an acute decline in performance and body composition associated with weakened hormone profiles. This study investigated the effects of a multi-ingredient performance supplement (MIPS) on body composition and hormone levels in college athletes following a six-week training protocol. Twenty male college athletes were equally assigned to MIPS and placebo (PLA) groups for supplementation (three pills, twice daily) in conjunction with resistance training and specialized sports training (e.g., nine total sessions/week) for six weeks. Dual Energy X-ray Absorptiometry determined body composition at weeks 0 and 6. Serum samples collected at weeks 0 and 6 determined free testosterone (FT), total testosterone (TT), IGF-1 and total estrogen (TE) levels. PLA experienced a significant decline in lean body mass (LBM) (−1.5 kg; p < 0.05) whereas the MIPS sustained LBM. The MIPS increased TT 21.9% (541.5 ± 48.7 to 639.1 ± 31.7) and increased FT 15.2% (13.28 ± 1.1 to 15.45 ± 1.3 ng/dL) (p < 0.05). Conversely, PLA decreased TT 7.9% (554.5 ± 43.3 to 497.2 ± 39.1 ng/dL), decreased FT 17.4% (13.41 ± 1.8 to 11.23 ± 2.55 ng/dL), and decreased FT:E 12.06% (p < 0.05). These findings suggest the MIPS can prevent decrements in LBM and anabolic hormone profiles during intense training periods.

Plasma levels of trace elements and exercise induced stress hormones in well-trained athletes

This study analyzed the variation and relationship of several trace elements, metabolic substrates and stress hormones activated by exercise during incremental exercise. Seventeen well-trained endurance athletes performed a cycle ergometer test: after a warm-up of 10 min at 2.0 W kg(-1), the workload was increased by 0.5 W kg(-1) every 10 min until exhaustion. Prior diet, activity patterns, and levels of exercise training were controlled, and tests timed to minimize variations due to the circadian rhythm. Oxygen uptake, blood lactate concentration, plasma ions (Zn, Se, Mn and Co), serum glucose, non-esterified fatty acids (NEFAs) and several hormones were measured at rest, at the end of each stage and 3, 5 and 7 min post-exercise. Urine specific gravity was measured before and after the test, and participants drank water ad libitum. Significant differences were found in plasma Zn and Se levels as a function of exercise intensity. Zn was significantly correlated with epinephrine, norepinephrine and cortisol (r = 0.884, P < 0.01; r = 0.871, P < 0.01; and r = 0.808, P = 0.05); and Se showed significant positive correlations whit epinephrine and cortisol (r = 0.743, P < 0.05; and r = 0.776, P < 0.05). Neither Zn nor Se levels were associated with insulin or glucagon, and neither Mn nor Co levels were associated with any of the hormones or substrate metabolites studied. Further, while Zn levels were found to be associated only with lactate, plasma Se was significantly correlated with lactate and glucose (respectively for Zn: r = 0.891, P < 0.01; and for Se: r = 0.743, P < 0.05; r = 0.831, P < 0.05). In conclusion, our data suggest that there is a positive correlation between the increases in plasma Zn or Se and stress hormones variations induced by exercise along different submaximal intensities in well-hydrated well-trained endurance athletes.