Effects of HMB on Endurance Performance in a Healthy Population: A Systematic Review and Meta-Analysis

ABSTRACT

Fernández-Landa, J, Todorovic, N, Santibañez-Gutierrez, A, Ostojic, SM, Calleja-González, J, Sekulic, D, and Mielgo-Ayuso, J. Effects of HMB on endurance performance in a healthy population: a systematic review and meta-analysis. J Strength Cond Res 38(4): e202-e210, 2024-β-hydroxy-β-methylbutyrate (HMB) has been used extensively as a dietary supplement for athletes and physically active people. However, the ergogenic effect of HMB supplementation on endurance performance is still unclear. Therefore, this systematic review and meta-analysis (SRMA) aimed to assess HMB supplementation on endurance performance and V̇O 2 max . This SRMA followed PRISMA guidelines. Three electronic databases were searched (PubMed/Medline, Web of Science [WOS], and Scopus) from inception until April 3, 2023. In this SRMA, human experimental trials, controlled with a placebo group, assessing the effect of HMB supplementation on endurance performance in a healthy population were included. The quality of the studies was assessed by the Physiotherapy Evidence Database (PEDro) scale. The study protocol was registered in the Prospective Register of Systematic Review (PROSPERO): CRD42022341790. Eleven studies involving 279 participants met the inclusion criteria. The results displayed a significant improvement on endurance performance (pooled standardized mean difference [SMD] = 0.58 [0.28-0.87]) and V̇O 2 max (pooled SMD = 0.58 [0.21-0.95]) after HMB ingestion. Moreover, after the exclusion of the studies not evenly distributed around the base of the funnel plot, the results continued to be significantly positive in endurance performance (pooled SMD = 0.38 [0.22-0.53]) and V̇O 2 max (pooled SMD = 0.25 [0.09-0.42]). In conclusion, HMB (3 g·d -1 ) ingestion during 2-12 weeks significantly improves endurance performance and V̇O 2 max .

Eight-Week Creatine-Glucose Supplementation Alleviates Clinical Features of Long COVID

Preliminary studies demonstrated beneficial effects of dietary creatine across different post-viral fatigue syndromes. Creatine is often co-administered with glucose to improve its potency yet whether glucose boost the efficacy of creatine in long COVID remains currently unknown. In this report, we investigate the effects of 8-wk creatine intake with and without glucose on patient-reported outcomes, exercise tolerance, and tissue creatine levels in patients with long COVID. Fifteen male and female long COVID adult patients (age 39.7±16.0 y; 9 women) with moderate fatigue and at least one of additional long COVID-related symptoms volunteered to participate in this randomized controlled parallel-group interventional trial. All patients were allocated in a double-blind parallel-group design (1 : 1 : 1) to receive creatine (8 g of creatine monohydrate per day), a mixture of creatine and glucose (8 g of creatine monohydrate and 3 g of glucose per day), or placebo (3 g of glucose per day) t.i.d. during an 8-wk intervention interval. Two-way ANOVA with repeated measures (treatment vs. time interaction) revealed significant differences in changes in total creatine levels between the groups, showing an interaction effect at two brain locations (right precentral white matter F=34.740, p=0.008; partial η2=0.72; left paracentral grey matter F=19.243, p=0.019; partial η2=0.88), with creatine and creatine-glucose outcompeted placebo to elevate creatine levels at these two locations. Several long COVID symptoms (including body aches, breathing problems, difficulties concentrating, headache, and general malaise) were significantly reduced in creatine-glucose group at 8-wk follow-up (p≤0.05); the effect sizes for reducing body aches, difficulties concentrating, and headache were 1.33, 0.80, and 1.12, respectively, suggesting a large effect of creatine-glucose mixture for these outcomes. Our preliminary findings suggest that supplying exogenous creatine with glucose could be recommended as an effective procedure in replenishing brain creatine pool and alleviating long COVID features in this prevalent condition.

Effects of six-month creatine supplementation on patient- and clinician-reported outcomes, and tissue creatine levels in patients with post-COVID-19 fatigue syndrome

Dietary creatine has been recently put forward as a possible intervention strategy to reduce post-COVID-19 fatigue syndrome yet no clinical study so far evaluated its efficacy and safety for this perplexing condition. In this parallel-group, randomized placebo-controlled double-blind trial, we analyzed the effects of 6-month creatine supplementation (4 g of creatine monohydrate per day) on various patient- and clinician-reported outcomes, and tissue creatine levels in 12 patients with post-COVID-19 fatigue syndrome. Creatine intake induced a significant increase in tissue creatine levels in vastus medialis muscle and right parietal white matter compared to the baseline values at both 3-month and 6-month follow-ups (p < .05). Two-way analysis of variance with repeated measures revealed a significant difference (treatment vs. time interaction) between interventions in tissue creatine levels (p < .05), with the creatine group was superior to placebo to augment creatine levels at vastus medialis muscle, left frontal white matter, and right parietal white matter. Creatine supplementation induced a significant reduction in general fatigue after 3 months of intake compared to baseline values (p = .04), and significantly improved scores for several post-COVID-19 fatigue syndrome-related symptoms (e.g., ageusia, breathing difficulties, body aches, headache, and difficulties concentrating) at 6-month follow-up (p < .05). Taking creatine for 6 months appears to improve tissue bioenergetics and attenuate clinical features of post-COVID-19 fatigue syndrome; additional studies are warranted to confirm our findings in various post-COVID-19 cohorts.

Molecular hydrogen modulates brain glutamate/GABA-glutamine cycle in overweight humans

INTRODUCTION

We evaluated whether 12-week intake of molecular hydrogen (H2) in 5 overweight adults (3 women; age: 50.2 ±11.9 years, body mass index: 29.4 ±2.1 kg/m2) affects brain levels of the glutamate-glutamine-GABA cycle, critical amino acid neurotransmitters in the mechanism of neuronal activation during appetite regulation.

METHODS

A 1.5-T single-voxel proton magnetic resonance spectroscopy was used to assess the tissue concentrations of relevant metabolites.

RESULTS

The mean glutamate and glutamate-plus-glutamine levels at the posterior cingulate gyrus decreased significantly during the study; this was accompanied by a significant drop in GABA levels at left prefrontal white matter, and glutathione levels at anterior cingulate gyrus. No changes in the brain metabolites were found in the comparable group of overweight individuals (n = 4, 2 women; age: 41.0 ±13.9, BMI 26.8 ±1.3 kg/m2) followed-up in the past without this treatment.

CONCLUSIONS

We showed a possible hydrogen-driven upregulation of neurotransmitters involved in appetite stimulation leading to hunger suppression and weight loss. Further studies analyzing appetite-controlling metabolic pathways affected by H2 would require monitoring of additional biomarkers of satiation and satiety during different feeding regimens.

Reduced tissue creatine levels in patients with long COVID-19: A cross-sectional study

Total creatine concentration in the skeletal muscle and brain of long COVID patients were significantly lower when compared to the reference values for the general population, as measured with proton magnetic resonance spectroscopy at 1.5-T in vastus medialis muscle, thalamus, and three bilateral cerebral locations across the white and gray matter.

The Effects of Hydrogen-Rich Water on Blood Lipid Profiles in Clinical Populations: A Systematic Review and Meta-Analysis

Over the last two decades, a plethora of disease models and human studies have confirmed the beneficial effects of molecular hydrogen (H2), a simple biotherapeutic gas. Recent small-scale studies evaluating the effects of hydrogen-rich water (HRW) on various metabolic conditions pointed to advantageous effects of HRW in regulating blood lipid profiles. However, to the best of the authors' knowledge, no systematic review and/or meta-analysis (SRMA) were published considering HRW consumption and lipid/lipoprotein status. Therefore, the aim of this SRMA was to assess the effects of HRW consumption on blood lipid panel in clinical populations. The search strategy was designed using PRISMA guidelines, and the databases PubMed/Medline, Web of Science, and Scopus were explored from inception until 4 October 2022. A total of seven studies satisfied all the eligibility criteria and were included in SRMA. The results for the pooled meta-analysis showed a significant reduction in total cholesterol, low-density lipoprotein, and triglycerides after HRW intake (p = 0.01), with small to moderate effects (pooled SMD = -0.23 (from -0.40 to 0.05); pooled SMD = -0.22 (from -0.39 to 0.04); pooled SMD = -0.38 (from -0.59 to 0.18), respectively). Our findings indicate that drinking HRW can significantly improve lipid status in the clinical populations. Additional studies are warranted to further validate this connection.

Prevalence of rapid weight loss in Olympic style wrestlers

Background

Methods

Results

Conclusions

Creatine consumption and liver disease manifestations in individuals aged 12 years and over

Despite the overwhelming safety evidence concerning creatine intake in various settings, there is still incomplete information whether dietary creatine affects liver health at the population level. The main aim of this cross-sectional population-based study was to evaluate the association between creatine intake through regular diet and liver disease manifestations, including liver fibrosis and hepatic steatosis, among individuals aged 12 years and over, using open-source data from the 2017-2018 U.S. National Health and Nutrition Examination Survey (NHANES). A total of 9254 male and female participants of all ages were included in the 2017-2018 NHANES round. We extracted data from the total sample population for participants who provided dietary data for individual foods via dietary interviews and examination data from liver ultrasound transient elastography. The final study sample consisted of 5957 participants (mean age 44.7 ± 21.0 years; 50.1% women), and the mean dietary creatine intake across the study population was 0.88 ± 0.71 g/day. Liver fibrosis and cirrhosis were diagnosed in 1703 (28.7%) and 288 (4.8%) participants, respectively; hepatic steatosis was identified in 2595 (43.7%) individuals. Binary logistic regression with multivariable model adjusted for age, gender, family income to poverty ratio, body mass index, total energy intake, and alcohol consumption showed that consuming more creatine (≥2 g/day) did not significantly increase the risk of liver fibrosis (OR = 0.92, 95% CI 0.70-1.21, p = .57), cirrhosis (OR = 0.94, 95% CI 0.53-1.65, p = .82), or hepatic steatosis (OR = 0.77, 95% CI 0.59-1.02, p = .07), as compared to participants who ingested <1 g of creatine daily. Dietary exposure to creatine through a regular diet is not associated with an increase in disease manifestations in individuals 12 years and over; further research is warranted to address the effects of excessive creatine intake (≥5 g/day) through a regular diet on liver health at the population level.

Rapid Weight Loss Practices in Grapplers Competing in Combat Sports

Background

Grappling is a wrestling style that combines different techniques such as freestyle wrestling, jiu-jitsu, judo, sambo, and others. As with other combat sports, it requires categorizing the athletes in weight classes, which leads to the use of certain methods to lose body weight in a short amount of time which poses a serious threat to athletes’ health and wellbeing. Therefore, the objective of this study was to investigate the most widespread rapid weight loss (RWL) methods and sources of influence used by grappling athletes.

Methods

A total of 145 athletes took part in the study by voluntarily filling out a questionnaire regarding their weight loss techniques and methods. They were divided into two groups, male (27.7 ± 5.2 years, 1.76 ± 0.13 m, and 82.1 ± 20 kg) and female (27.33 ± 6.3 years, 1.65 ± 0.08 m, and 64.3 ± 10.4 kg), for further statistical analysis. After calculating descriptive statistics for all the variables, a t-test was conducted for gender differences in weight loss and weight regain, and a chi-square test measured the diversity in techniques and source of influence.

Results

Out of 145 participants, 120 athletes (85.2%) reported engaging in rapid weight loss prior to weigh-in. Coaches (52.4 and 59%) and teammates (42.6 and 22.1%) seemed to be the most influential on their rapid weight-loss strategies, whereas physicians (17.1 and 17.9%) and parents (23.2 and 23.1%) were the least influential. A statistical difference between men and women (p = 0.05) was found when teammates were a source of influence (42.6 and 21.1%, respectively). Regarding the methods used, both groups practiced gradual dieting (85.4 and 79.5%) as the most prevalent, followed by increased exercise (79 and 66.6%) and sauna (78.7 and 66.6%). Moreover, men trained in plastic suits significantly more often than women (67.1 vs. 41%, p = 0.01).

Conclusion

Rapid weight loss is detrimental to athletes’ health and wellbeing. Hence, it is crucial to find and implement methods that will control and ultimately limit its use in combat sports. Physicians and nutritionists need to be closely linked with the staff, collaborate and supervise the weight cutting.

Effects of acute β-alanine supplementation on countermovement jump performance after a 4x400 m running fatigue protocol

This study aimed to examine the effect of acute beta-alanine (β-alanine) supplementation on jump performance after a strenuous fatigue protocol. Twelve healthy young men (age 21.4±0.5 years, body height 180.2±5.8 cm, body mass 76.6±9.2 kg) volunteered to participate in this randomized, double-blind, placebo-controlled trial. The experimental group ingested 3.2 g of β-alanine (separated into two 1.6 g dosages) mixed with 23 g of glucose, whereas the placebo group ingested two dosages containing 23 g of glucose. Following the supplementation intake, participants completed a jump protocol involving countermovement jump (CMJ) and four consecutive countermovement jumps (CMJ-4). Subsequently, a 4x400 m running fatigue protocol was carried out to produce fatigue. After the fatigue protocol, the same jumping tests were repeated, CMJ and CMJ-4, to evaluate the loss in jump height. The Mann-Whitney U test was used to analyze differences between the groups, whereas Wilcoxon signed-rank test was conducted to analyze differences within the groups with statistical significance set at p&lt;.05. After β-alanine supplementation, no significant decrease was found in the experimental group in none of the tests after the fatigue protocol. Conversely, a significant decrease was noticed in the placebo group in CMJ but not in the CMJ-4 test. In conclusion, an acute β-alanine supplementation could attenuate jump height loss after the fatigue protocol. Therefore, athletes and coaches should consider acute β-alanine supplementation to attenuate sports performance decrease after high-intensity exercises in which muscle acidosis is highly increased.

Food Creatine and DXA-Derived Body Composition in Boys and Girls Aged 8 to 19 Years

Several small-scale trials indicate a positive correlation between dietary creatine intake and fat-free mass in the pediatric population; whether this connection occurs at the population-wide level remains currently unknown. The main purpose of this cross-sectional study was to calculate the amount of creatine consumed through a regular diet among U.S. boys and girls aged 8 to 19 years, and investigate the link between creatine consumption and dual-energy X-ray absorptiometry (DXA)-derived body composition indices in this population. Data were obtained from the National Health and Nutrition Examination Survey 2017-2018 round, with dietary information and whole-body DXA body composition measures extracted for respondents aged 8 to 19 years (1273 participants, 649 boys and 624 girls). Individual values for total grams of creatine consumed per day for each participant were computed using the average amount of creatine (3.88 g/kg) across all creatine-containing foods. The primary exposure was the mean daily intake of creatine; the primary and secondary outcomes comprised lean mass excluding bone mineral content (BMC), and bone mineral density, BMC, lean mass including BMC, fat mass, and percent body fat, respectively. The average intake of creatine across the sample was 0.65 ± 0.72 g/day (95% CI, from 0.61 to 0.69). Creatine positively correlated with lean mass (excluding BMC) and BMC across the whole sample (r = .18 and .20, respectively; P < .001); a significant negative correlation was found between creatine intake and percent body fat (r = −.09; P = .001). The higher intake of creatine was associated with higher lean mass in girls and higher BMC in boys, while taking more creatine corresponded to less body fat for both genders (P < .05). Our findings indicate a significant correlation between dietary creatine and DXA-derived body composition biomarkers in a nationally representative cohort of U.S. youth. These results justify further research of creatine’s role in modifying body morphology in the pediatric population, taking into account the age and sex specific traits.

Effects of 6-Month Supplementation with Multi-Component Herbal Supplement PhytodynamicTM on Mitochondrial Function, Telomere Length, and Chronic Inflammation in Adults Aged 65 Years and Older: A Pilot Trial

Herbal supplements are often used by elderly populations in aim to manage age-related traits; yet, most have shown limited benefits, keeping a quest for safe and effective longevity-promoting mixtures open. The main aim of the present study was to evaluate the effects of 6-month supplementation with multi-component herbal mixture P-DNA for telomere length, biomarkers of mitochondrial function and chronic inflammation, and self-reported adverse events in men and women aged 65 years and older. Fourteen older adults (74.6 ± 6.3 years, height 164.1 ± 13.0 cm, weight 69.9 ± 13.4 kg; 11 women) signed an informed consent to voluntarily participate in this randomized controlled parallel-group pilot trial. All participants were allocated in a double-blind design to receive either P-DNA or placebo (inulin) during a 6-month intervention period, with the outcomes assessed at baseline and 6-month follow-up were biomarkers of mitochondrial function (fibroblast growth factor 21, growth-differentiation factor 15), inflammation (high-sensitive C-reactive protein, interleukin-6, and amyloid A), and telomere length. Two-way analysis of variance with repeated measures was used to establish if any significant differences existed between patients’ responses over time of intervention; for data with nonhomogenous variances the Kruskal– Wallis test was employed for the between group comparisons and Freidman’s test for the within group comparisons. Growth-differentiation factor 15 significantly dropped after PhytoDyNAmic^TM intervention as compared to the baseline levels (P = 0.02), while serum interleukin-6 significantly increased from baseline levels in both groups at 6-month follow-up (P < 0.05). No participant reported major side effects of any intervention. PhytoDyNAmic^TM appears to favorably affect mitochondrial function in adults aged 65 years and older; additional studies are needed to corroborate these promising findings.

The effects of 6-month hydrogen-rich water intake on molecular and phenotypic biomarkers of aging in older adults aged 70 years and over: A randomized controlled pilot trial

In this randomized controlled pilot trial, we investigated the effects of a 6-month intake of hydrogen-rich water (HRW) on several molecular and phenotypic biomarkers of aging in older adults aged 70 years and over. Forty older adults (20 women) were randomly allocated in a parallel-group design to receive 0.5 L per day of HRW (15 ppm of hydrogen) or control drink (0 ppm of hydrogen) during a 6-month intervention period. The biomarkers assessed at baseline and 6-month follow up were molecular markers in the blood (DNA and chromosomes, nutrient sensing, protein, and lipid metabolism, oxidative stress and mitochondria, cell senescence, inflammation), brain metabolism, cognitive functioning, physical function and body composition, resting blood pressure, facial skin features, sleep outcomes, and health-related quality of life. The mean age, weight, and height of study participants were 76.0 ± 5.6 years, 78.2 ± 16.1 kg, height 167.5 ± 11.5 cm, respectively. A significant treatment vs. time interaction was found for telomere length (P = 0.049), with the length increased after HRW intervention (from 0.99 ± 0.15 at baseline to 1.02 ± 0.26 at follow up) and decreased after drinking control water (from 0.92 ± 0.27 to 0.79 ± 0.15). A marker of DNA methylation (Tet methylcytosine dioxygenase 2, TET2) expression at 6-month follow-up increased in both groups, yet the degree of elevation was significantly higher in HRW (from 0.81 ± 0.52 at baseline to 1.62 ± 0.66 at follow up) comparing to the control water (from 1.13 ± 0.82 to 1.76 ± 0.87) (P = 0.040). A strong trend for treatment vs. time interaction was found for a degree of DNA methylation (P = 0.166), with the methylation increased in the HRW group (from 120.6 ± 39.8 ng at baseline to 126.6 ± 33.8 ng at follow up) and decreased after taking control water (from 133.6 ± 52.9 ng to 121.2 ± 38.4 ng). HRW was superior to control water to increase brain choline and NAA levels in the left frontal grey matter, brain creatine at the right parietal white matter, and brain NAA at the right parietal mesial grey matter (P < 0.05). No significant differences were found between interventions for other outcomes (P > 0.05), except for a significantly improved chair stand performance after HRW intervention compared to the control water (P = 0.01). Owing to pleiotropic mechanisms of hydrogen action, this simple biomedical gas could be recognized as a possible anti-aging agent that tackles several hallmarks of aging, including loss of function and telomere length shortening. The study was registered at ClinicalTrials.gov (NCT04430803).

Hydrogen-rich water and caffeine for alertness and brain metabolism in sleep-deprived habitual coffee drinkers

The main aim of this randomized-controlled cross-over interventional trial was to assess the acute effects of taking a single dose of hydrogen-rich water (HRW), and compare it with caffeine, HRW plus caffeine, and control water, for alertness, brain metabolism, brain and oxygen saturation, and self-reported adverse events in healthy men and women who were habitual coffee drinkers and were sleep-deprived for 24 hr. Sixteen apparently healthy young adults (8 men and 8 women; age 24.0 ± 3.5 years) were allocated in a cross-over design to receive a single-dose drink of HRW (8 ppm), caffeine (50 mg), HRW plus caffeine, or control drink (tap water) in the morning after 24-hr sleep deprivation and 12-hr fasting. The primary and secondary outcomes were assessed at baseline (pre-intervention) and 15-min follow-up. Significantly less time was needed to complete trail-making test after both HRW and HRW plus caffeine compared with the control drink (p < .05). The number of errors in the symbol digit modalities test was significantly lower after drinking HRW or caffeine than control drink (p < .05). Both HRW and caffeine significantly increased the choline-to-creatine ratio in several brain regions (frontal white and gray matter), while HRW and the combination intervention also affected brain metabolism in the paracentral brain. No participants reported any side effects from any intervention. The attention enhancement driven by HRW appears along with changes in brain metabolism. Being generally recognized as a safe intervention, hydrogen could be thus recommended as a novel intervention that upholds attention in stressed conditions, with its metabolic footprint likely different from caffeine.

Effects of 7-day supplementation with escalating doses of citrulline nitrate on resting and post-exercise blood pressure and safety biomarkers in healthy men: A randomized controlled trial

We investigated the effects of 7-day supplementation with three different dosages of citrulline nitrate (CN) on blood pressure at rest and after exercise, biochemical safety markers, and self-reported outcome measures of adverse events in healthy men. 12 apparently healthy young men (age 25.9 ± 4.0 years; weight 78.6 ± 10.0 kg, height 181.0 ± 7.0 cm) volunteered to participate in this double-blind, randomized, placebo-controlled cross-over trial. The dosages of CN were 1.5 g per day (low dose), 3.0 g per day (medium dose), and 6.0 g per day (high dose). No significant differences were found for systolic and diastolic blood pressure and heart rate at rest and after exercise between varying doses of CN and placebo ( p > 0.05). In addition, hematological indices, biochemical variables, and clinical enzyme profiles were not affected by either intervention ( p > 0.05), and the type and frequency of side effects were comparable to the placebo group. Citrulline nitrate was safe and well tolerated when administered for 7 days in dosages up to 6 g per day.

A single-dose nitrate-producing dietary supplement affects cardiorespiratory endurance and muscular fitness in healthy men: A randomized controlled pilot trial

Introduction:

The main aim of this pilot study was to examine the effects of a single-dose intervention with a novel nitrate-producing formulation (MagNOVOx™) on biomarkers of cardiorespiratory endurance and muscular fitness in 12 healthy men.

Methods:

The study participants (age = 22.7 ± 2.8 years, height = 184.1 ± 5.7 cm, and weight = 82.5 ± 8.4 kg) were randomly allocated to receive either a single dose of MagNOVOx™ or a placebo (inulin) in a cross-over design. The primary outcome for this study was the change in running time to exhaustion evaluated at baseline (before supplementation) and post-intervention.

Results:

Time to exhaustion was improved after the intervention in 8 out of 11 participants (72.7%) who received MagNOVOx™, and in 1 out of 11 participants (9.1%) who received placebo (p = 0.004), and MagNOVOx™ outcompeted placebo in terms of improving leg press performance (p < 0.01). No significant differences between MagNOVOx™ and placebo were found for blood pressure responses (p > 0.05).

Conclusion:

These promising findings should be further corroborated in medium- and long-term trials, and different populations, while the exact mechanism of MagNOVOx™ requires additional physiological studies.

Temporal trends in dietary creatine intake from 1999 to 2018: an ecological study with 89,161 participants

Introduction

We described here the annual variations in mean dietary creatine intake from 1999 to 2018 in U.S. children and adults using National Health and Nutrition Examination Survey (NHANES) database.

Methods

Dietary intake information from ten consecutive rounds of NHANES (from 1999 to 2000 to 2017–2018) was extracted for a total of 89,161 respondents aged 0–85 years. Individual values for total grams of creatine consumed per day were computed using the average amount of creatine (3.88 g/kg) across all creatine-containing food sources.

Results

The average daily intake of creatine across the entire sample was 0.70 ± 0.78 g (95% confidence interval [CI], from 0.69 to 0.71) and 13.1 ± 16.5 mg/kg body weight (95% CI, from 13.0 to 13.2). A significant negative trend for dietary creatine intake was found in infants (r = − 0.019; P = 0.042), and children and adolescents (r = − 0.024; P < 0.001).

Conclusions

Our findings suggest a variation in dietary creatine intake in the U.S. population during the past 20 years, with young persons tend to consume fewer grams of creatine per day from 1999 onwards. Long-running studies are highly warranted to assess possible health consequences of variable creatine intake in human nutrition.

Cardiorespiratory Fitness in Volleyball Athletes Following a COVID-19 Infection: A Cross-Sectional Study

Athletes' lifestyles have been dramatically affected by the coronavirus disease 2019 (COVID-19) pandemic. Since COVID-19 primarily affects the respiratory system and to a lesser degree the cardiovascular system, the goal of this study was to examine the effects of COVID-19-caused detraining on cardiorespiratory fitness (CRF) of recently recovered volleyball athletes. Sixteen experienced volleyball athletes (age 24 ± 4.5 years) who were recently diagnosed and recovered from a COVID-19 infection volunteered to participate in this study and were tested for CRF and spirometry. Given that participants had only mild symptoms of infection, the primary focus of this study was on the effects of detraining on CRF. On average, the time to exhaustion was 9.4 ± 1.4 min. VE, VCO2, RER and oxygen pulse increased, heart rate exceeded 90% of predicted values, and peak VO2 values were typical for this level of athlete (44.1 ± 3.4 mL/kg). Pulmonary function reflected in FVC, FEV1/FVC and MVV values were well above 80% of predicted values for each of the participants while electrocardiography revealed no ischemia, arrythmias or conduction and repolarization abnormalities were found in the tested subjects. Therefore, it can be concluded that participants experienced typical consequences of detraining. Due to a lack of CRF data prior to COVID-19 infection, we were unable to estimate the magnitude detraining had on CRF. Complete CRF assessment after COVID-19 infection in athletes can be useful for screening of residual myocardial and/or respiratory system damage for safe return-to-play decisions.

The Effects of 6-Week Supplementation with Multicomponent Herbal Extract on Exercise Performance, Antioxidant Status and Telomere Length, and Self-Reported Side Effects in Healthy Men: A Randomized Controlled Pilot Trial

The main aim of this study was to examine the effects of medium-term supplementation with an eight-herbs extract on running performance, biomarkers of antioxidant status and telomere length, and self-reported outcome measures of safety events in healthy men. Ten healthy young men (age 23.1±3.2 years, weight 73.7±9.9kg, and height 179.4±8.0cm) volunteered to participate in this randomized controlled trial. The participants were allocated in a double-blind cross-over design to receive either an eight-herbs extract or placebo during a 6-week intervention period. Two-way mixed analysis of variance (treatment vs. time interaction) revealed no significant differences for exercise performance outcomes and telomere length between groups (P>0.05). Compared with placebo, P-DNA provoked a significant rise in serum total antioxidant capacity (316.0±183.4µmol/mL at baseline; 792.7±68.1µmol/mL at follow-up in the eight-herbs extract group vs. 298.1±90.7µmol/mL at follow-up in the placebo group; P<0.001), and less reduction in serum superoxide dismutase levels at follow-up (150.4±5.1IU/mL at baseline; 145.5±3.0IU/mL at follow-up in the eight-herbs extract group vs. 139.3±3.3IU/mL at follow-up in the placebo group; P=0.01). No participant reported any side effects of either intervention. The eight-herbs extract can thus be recommended as a well tolerated dietary supplement that can enhance antioxidant capacity in healthy men. This trial was registered at ClinicalTrials.gov (NCT04263246).

Advancing health-enhancing physical activity at workplace: Sport4Heath 2020 scientific forum

Physical activity at workplace can positively impact various wellbeing outcomes yet developing and implementing exercise programs that are straightforward, time-efficient and widely applicable remains a notable public health challenge. Sport4Health Network (SPORT4H) project co-funded by the European Union Erasmus+ programme unites health and sport professionals in an effort to encourage participation in physical activity among working population and reduce health risk factors for lifestyle diseases. A two-day SPORT4H scientific forum on non-traditional types of work-place exercise interventions was organized from 14th to 15th September 2020, to critically evaluate evidence on stretching and resistance exercise programs targeted to working population in aim to identify knowledge gaps and future areas of research and application. Evidence on traditional interventions (e.g., walking initiatives, active travel) appears more robust while only few studies evaluated the applicability of non-traditional PA programs in working population. However, we identified a moderate-to-strong link between non-traditional PA programs at the workplace and several health-related physical fitness indices, with resistance exercise turned out to be superior to other exercise interventions analyzed. It appears that low-volume high-repetition resistance exercise favorably affects musculoskeletal disorders, work performance and health-related quality of life in employees who exercised at least 3 times per week for over 8 weeks. In terms of safety, screening protocols should employ health-related questionnaires, adopting a progressive training load, and prescribing training programs to individual participants' needs. Implementing non-traditional PA programs aimed to improve health-related physical fitness and counteract sedentary behavior at workplace might be therefore of utmost importance to contribute to health promotion in this sensible population.

Radiation exposure to nuclear medicine staff involved in PET/CT practice in Serbia

The purpose of this work is to evaluate the radiation exposure to nuclear medicine (NM) staff in the two positron emission tomography-computed tomography centres in Serbia and to investigate the possibilities for dose reduction. Dose levels in terms of Hp(10) for whole body and Hp(0.07) for hands of NM staff were assessed using thermoluminescence and electronic personal dosemeters. The assessed doses per procedure in terms of Hp(10) were 4.2-7 and 5-6 μSv, in two centres, respectively, whereas the extremity doses in terms of Hp(0.07) in one of the centres was 34-126 μSv procedure(-1). The whole-body doses per unit activity were 17-19 and 21-26 μSv GBq(-1) in two centres, respectively, and the normalised finger dose in one centre was 170-680 μSv GBq(-1). The maximal estimated annual whole-body doses in two centres were 3.4 and 2.0 mSv, while the corresponding extremity dose in the later one was 45 mSv. Improvements as introduction of automatic dispensing system and injection and optimisation of working practice resulted in dose reduction ranging from 12 up to 67 %.

Discrimination of older people in Serbia

Abuse of older people is a single or a repeated act or a failure to act happening in a relationship between two persons based on trust that causes pain or disturbance on the part of the older person. Red Cross of Serbia is the initiator and the founding member of Humanas (the network of 15 civil society organisations dealing with the issues of older people) and is spearheading a campaign of sensitisation of the public in relation to discrimination, neglect and abuse of older people.

Humanas has educated volunteers in Elder Abuse and Discrimination prevention.

A survey has been done in 8 cities in Serbia polling 250 older people of both sexes, age 65 or above. The survey results demonstrate that 44% of all the polled people are familiar with the existence of abuse. Alarmingly, as high as 32% of older people have been exposed to some form of abuse, with the most frequent form being verbal abuse (11.2%) The polled older people have stressed that they hate being called names, made fun of and called stupid or illiterate, within their families as well as in the general community. As for prevention, 52% of the polled older people think that ‘everybody’, meaning both public and civil sector should play a role in prevention.

Conclusion

The problem of abuse of older people has to be approached from a multi-sector and multi-disciplinary perspective. The emphasis should be on new, deeper surveys, education of professionals, family members and other care takers.

Percutaneous coronary intervention of an anomalous right coronary artery originating from the left coronary artery

Anomalous origin of the right coronary artery is a rare congenital anomaly that was first described in 1948 by White and Edwards. It is well established that an anomalous origin of the right coronary artery can lead to angina pectoris, myocardial infarction, or sudden death, in the absence of atherosclerosis. Thus from the literature data it has been also suggested that the abnormal origin and course of anomalous coronary arteries could make them more prone to atherosclerosis due to altered flow patterns. We report our experience involving one patient who had significant atherosclerotic disease and was successfully treated with percutaneous coronary intervention (PCI) and stent implantation in an anomalous right coronary artery arising from the left coronary artery.

Elder Abuse

Elder abuse is a serious problem-each year hundreds of thousands of seniors are abused. Although the problem is described, defined and legislatures exist in many countries elder abuse is not still recognized as public health problem. Red Cross of Serbia has organized education of volunteers in Elder Abuse and Discrimination topic which is very important in sensibilisation among community-dwelling. Volunteers (N=226) were informed with generally accepted definitions, research in the field and legislature in Serbia concerning this issue and proposed network for prevention of elder abuse. Interactive workshops gave us data: distribution and types of elder abuse in their local communities and obstacles in referring and positive examples from practice as problem solving models.

Differential effects of NMDA and AMPA/kainate receptor antagonists on superoxide production and MnSOD activity in rat brain following intrahippocampal injection

The involvement of NMDA and AMPA/kainate receptors in the induction of superoxide radical production in the rat brain was examined after injection of kainate, non-NMDA receptor agonist, kainate plus 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX), selective AMPA/kainate receptor antagonist, or kainate plus 2-amino-5-phosphonopentanoic acid (APV), selective NMDA receptor antagonist. Competitive glutamate receptor antagonists were injected with kainate unilaterally into the CA3 region of the rat hippocampus. We investigated superoxide production and mitochondrial MnSOD activity after injection. The measurements took place at different times (5, 15 min, 2, 48 h and 7 days) in the ipsi- and contralateral hippocampus, forebrain cortex, striatum, and cerebellum homogenates. Used glutamate antagonists APV and CNQX both expressed sufficient neuroprotection in sense of decreasing superoxide production and increasing MnSOD levels, but with differential effect in mechanisms and time dynamics. Our findings suggest that NMDA and AMPA/kainate receptors are differentially involved in superoxide production. Following intrahippocampal antagonists injection they, also, interpose different neuroprotection effect on the induction of MnSOD activity in distinct brain regions affected by the injury, which are functionally connected via afferents and efferents. It suggests that MnSOD protects the cells in these regions from superoxide-induced damage and therefore may limit the retrograde and anterograde spread of neurotoxicity.

Distribution and regulation of expression of serum- and glucocorticoid-induced kinase-1 in the rat kidney

The serum- and glucocorticoid-induced kinase-1 (sgk1) increases the activity of a number of epithelial ion channels and transporters. The present study examines the distribution and subcellular localization of sgk1 protein in the rat kidney and the regulation of levels of expression induced by steroids. The results indicate that the kidney expresses predominantly the sgk1 isoform with a distribution restricted to the thick ascending limb of Henle, distal convoluted, connecting and cortical collecting tubules. Within cells, sgk1 strongly associates with the microsomal fraction of homogenates and it colocalizes with the Na+,K+-ATPase to the basolateral membrane. Analysis of the levels of expression of sgk1 by Western blotting and immunohistochemistry indicates constitutive high expression under basal conditions. Approximately half of the basal level is maintained by glucocorticoids whereas physiological fluctuations of aldosterone produce minor changes in sgk1 abundance in adrenal-intact animals. These results do not support the notion that physiological changes of aldosterone concentration turn the expression of sgk1 'on and off' in the mammalian kidney. Additionally, localization of sgk1 to the basolateral membrane indicates that the effects mediated by sgk1 do not require a direct interaction with the ion channels and transporters whose activity is modulated, since most of these proteins are located in the apical membrane of renal epithelial cells.