A Decrease in Branched-Chain Amino Acids after a Competitive Male Professional Volleyball Game-A Metabolomic-Based Approach.

A competitive volleyball game is a highly metabolic and physically demanding event for professional players. This study aimed to investigate whether a single game at the end of a preseason promotes changes in the biochemical markers of physical exercise responses and the metabolomic profile of professional volleyball players. This cross-sectional study included 13 male Brazilian professional volleyball players. Food intake, body composition, heart rate, physical movement variables, and blood biochemical indicators were evaluated. For non-target metabolomic analysis, serum samples were subjected to 500 MHz Nuclear Magnetic Resonance. Data analysis showed no significant difference in the biochemical indicators after the game (p > 0.05). The level of metabolites present in the groups of the main components (ß-hydroxybutyrate, arginine/lysine, isoleucine, leucine, and valine) had decreased after the game. However, formic acid and histidine levels increased. Among the compounds not part of the main components, hypoxanthine and tyrosine increased, whereas low-density lipoprotein and very low-density lipoprotein levels decreased. After the game, the metabolomic profiles of players showed significant negative variations in essential amino acids (leucine, valine, and isoleucine). These decreases might be influenced by athlete diet and reduced glycogen storage due to lower carbohydrate intake, potentially impacting serum-essential amino acid levels via oxidation in skeletal muscle. The study provides insights for developing metabolic compensation strategies in athletes.

Analysis of ingredient list and nutrient composition of plant-based burgers available in the global market.

The nutrient composition of plant-based burgers is a key factor when making their purchase/consumption decision to maintain a balanced diet. For this reason, ingredient list and nutritional information of burgers launched in the global market were retrieved from their labels. Products were classified based on the technology development, market position and region of the manufacturer. From the ingredient analysis, we observed a high heterogeneity in the ingredients used, a predominance of soy and wheat as main sources of proteins, and the increasing use of new protein sources (e.g. peas, other types of beans and pseudo-cereals). Oil was the most cited ingredient followed by salt. Nutritional composition varied mainly depending on the region with no clear pattern among countries. To less extent, technology development resulted in traditional products with lower amounts of protein and higher amounts of carbohydrates. Vegan and vegetarian products showed limited differences due to the high intra-heterogenicity.

Yeast cells-xanthan gum coacervation for hydrosoluble bioactive encapsulation.

This study assessed the technological feasibility of microencapsulating vitamin C (VC) via coacervation between yeast cells (YC) and xanthan gum (XG). The interaction efficiency between YC and XG was examined across various pHs and ratios, while characterizing the microcapsules in terms of encapsulation efficiency, particle size, and thermal and chemical stability. Additionally, in vitro digestion experiments were conducted to determine the digestion efficiency and bioavailability of the bioactive compound. The optimally produced microcapsules exhibited favorable functional attributes, including low water activity (≤ 0.3) and particle size (≤ 33.52 µm), coupled with a high encapsulation efficiency (∼ 86.12 %). The microcapsules were able to increase the stability of VC at high temperatures and during storage when compared to the control. The in vitro experiment revealed that the microcapsules effectively retained approximately 50 % of the VC in simulated gastric fluid, with up to 80 % released in simulated intestinal fluid. However, due to prior degradation in the simulated gastric fluid, the achieved bioavailability was around 68 %. These results are promising, underscoring the potential of these microcapsules as a viable technology for encapsulating, protect, and releasing water-soluble bioactives in the GI tract.

Comparison of the effects of pea protein and whey protein on the metabolic profile of soccer athletes: a randomized, double-blind, crossover trial.

Introduction: Pea protein (PP) concentrate is a plant-based alternative to animal protein sources, such as whey protein (WP). In addition to its valuable amino acid composition, PP has a low environmental impact, making it a sustainable, nutritious, and viable alternative for enhanced sports performance, such as in soccer. PP Therefore, this study aimed to evaluate the effects of PP and WP supplementation on biochemical and metabolic parameters in soccer players. Methods: Twelve male under-20 soccer players were included in this double-blind, randomized crossover intervention study. For 10 consecutive days, each participant received either 0.5 g/kg of the PP or WP supplementation after training, starting 7 days before the test game, and continuing until 2 days after. After a 4-day washout period, the athletes switched groups and the intervention was restarted. Blood samples were collected before and after the game, as well as 24 h, 48 h, and 72 h intervals thereafter. Creatine kinase (CK), aspartate transaminase, alanine transaminase (ALT), lactate (LA), urea, creatinine, and uric acid were analyzed using commercial kits. Exploratory metabolic profiling of the serum samples was performed using nuclear magnetic resonance spectroscopy. Results: A comparison of biochemical markers showed that the PP group had lower CK in the post-game moment, 24 h, and 48 h. Lower LA in the post-game moment, and lower ALT in the post-game moment and at 24 h. Of the 48 metabolites analyzed, 22 showed significant differences between the time points, such as amino acids, ketone bodies, and glucose metabolism. Glutamate and lactate levels significantly increased between the pre- and post-game moments in the WP group. After the game, the WP group exhibited reduced levels of metabolites such as arginine and taurine, whereas no such change was observed in the PP group. There was no difference in metabolites 72 h after the game. Conclusions: Despite the slight advantage of the PP group in specific biochemical markers, these differences are not sufficient to justify the choice of a particular type of protein. However, the results highlight the viability of plant protein as a potential alternative to animal protein without compromising athletic performance or recovery.

Effect of gas exchange data selection methods on resting metabolic rate estimation in young athletes.

This cross-sectional study analysed the effect of the gas exchange data selection methods on the resting metabolic rate (RMR) estimation and proposed a protocol shortening providing a suitable RMR estimation for young athletes. Sixty-six healthy young Brazilian athletes performed a 30-minute RMR assessment. Different methods of gas exchange data selection were applied: short and long-time intervals, steady-state (SSt), and filtering. A mixed one-way ANOVA was used to analyse the mean differences in gas exchange, RMR, respiratory exchange ratio (RER), and coefficients of variation across all methods. Additionally, paired Student's t-test were used to compare the first and best SSt RMR values for each SSt method (3, 4, and 5-min). The 5-min SSt method provided the lowest RMR estimate (1454 kcal.day-1). There was a statistical difference between methods (F = 2.607, p = 0.04), but they presented a clinically irrelevant absolute difference (~36 kcal.day-1). There were no differences in RER among methods. In addition, using the SSt method, 12 minutes of assessment were enough to obtain a valid estimation of RMR. The 5-min SSt method should be employed for assessing the RMR among young athletes, considering the possibility of obtaining a shortened assessment (~12 min) with an acceptable and low coefficient of variation.

Enhancing satiety and aerobic performance with beer microparticles-based non-alcoholic drinks: exploring dose and duration effects.

Beer is an alcoholic beverage, rich in carbohydrates, amino acids, vitamins and polyphenols, consumed worldwide as a social drink. There is a large number of beer styles which depends on the ingredients and brewing process. The consumption of beer as a fluid replacement after sport practice is a current discussion in literature. A non-alcoholic pale-ale microparticles-based beverage (PABM) have been previously designed, however, its phenolic profile and ergogenic effect remain unknown. Thus, this study aims to verify the ergogenic potential (increase of running performance) of PAMB in male Wistar rats. Beer microparticles were obtained by spray drying and beverages with different concentrations were prepared in water. Wistar rats were subjected to a training protocol on a treadmill (5 times/week, 60 min/day) and daily intake of PABM (20 mg.kg-1 or 200 mg.kg-1) or water by gavage. Chlorogenic acid was found to be the main component in the phenolic profile (12.28 mg·g-1) of PABM analyzed with high-performance liquid chromatography and mass spectrometry. An increase in the aerobic performance was observed after 4 weeks in the 20 mg.kg-1 group, but the same dose after 8 weeks and a higher dose (200 mg.kg-1) blunted this effect. A higher dose was also related to decrease in food intake. These data suggest that PABM can improve satiety and aerobic performance, but its effect depends on the dose and time of consumption.

Effectiveness of current protein recommendations in adolescent athletes on a low-carbon diet.

Adolescent athletes require adequate energy and nutrient supply to support growth, development, and the demands associated with exercise and training. However, they are susceptible to nutritional inadequacies affecting their health and physical performance. Food choices with nutrient adequacy and environmental protection is crucial for a sustainable diet. Therefore, we aimed to assess the adequacy of low-carbon diets to meet the protein requirements of adolescent athletes. Therefore, a cross-sectional observational study was conducted with 91 adolescent athletes from sports clubs in Rio de Janeiro who underwent anthropometric and food consumption assessments. To estimate the environmental impact of anthropogenic activities, the sustainability indicators carbon footprint (CF) and water footprint (WF) were used. The CF of the athlete's diet was compared with the benchmark of 1,571 g CO2eq/cap/d estimated by the World Wildlife Fund (WWF). Protein recommendations according to the American Dietetic Association (ADA) for athletes and protein food groups according to the low-carbon EAT-Lancet reference diet were used as references. The results were stratified by sport modality, age, sex, and income range. The Mann-Whitney test was performed, followed by the Kruskal-Wallis test with Dunn's post-hoc test to assess the differences between groups using the statistical program GraphPad PRISM® version 8.0. CF and WF were directly associated with total energy intake, total protein intake, animal-origin protein intake, and the food groups of meat and eggs. Significant differences were observed in the environmental impact of diet based on sports groups and gender. The athletes' profile with higher environmental impact was male, middle-income class, and of any age group. The quartiles of CF of the overall diets were above the 1,571 g CO2eq/cap/d benchmark. Additionally, ADA's recommended range of daily protein consumption was met by most athletes, even in the lowest quartile of CF. Thus, a diet with a lower environmental impact can meet protein recommendations in adolescent athletes. The results found are of interest to the sports and food industries. It could help in designing a balanced diet for athletes as well as ensure less negative environmental impacts of food production and consumption.

Bioactive Compounds from Pale Ale Beer Powder Attenuate Experimental Colitis in BALB/c Mice.

Phenolic compounds (PCs) present in foods are associated with a decreased risk of developing inflammatory diseases. The aim of this study was to extract and characterize PCs from craft beer powder and evaluate their potential benefits in an experimental model of inflammatory bowel disease (IBD). PCs were extracted and quantified from pure beer samples. BALB/c mice received either the beer phenolic extract (BPE) or beer powder fortified with phenolic extract (BPFPE) of PCs daily for 20 days by gavage. Colon samples were collected for histopathological and immunohistochemical analyses. Dextran sodium sulfate (DSS)-induced mice lost more weight, had reduced colon length, and developed more inflammatory changes compared with DSS-induced mice treated with either BPE or BPFPE. In addition, in DSS-induced mice, the densities of CD4- and CD11b-positive cells, apoptotic rates, and activation of NF-κB and p-ERK1/2 MAPK intracellular signaling pathways were higher in those treated with BPE and BPFPE than in those not treated. Pretreatment with the phenolic extract and BPFPE remarkably attenuated DSS-induced colitis. The protective effect of PCs supports further investigation and development of therapies for human IBD.

Impact of Precompetitive Training on Metabolites in Modern Pentathletes.

PURPOSE: Modern pentathlon is a multidisciplinary sport that involves exhaustive training which can cause tissue damage and metabolic changes. However, few studies have evaluated the metabolic changes that occur in pentathletes. Accordingly, we aimed to evaluate the metabolomic profile of pentathletes during a 3-week training period before competition using nuclear magnetic resonance. METHODS: Blood samples from 6 members of a Brazilian modern pentathlon team were collected at the beginning (Pre1, Pre2, and Pre3) and end (Post1, Post2, and Post3) of each week. Low molecular-weight metabolite profiles were analyzed by nuclear magnetic resonance spectroscopy, and biochemical markers were assessed using enzyme-linked immunosorbent assays. Data were assessed using partial least-squares discriminant analysis and univariate statistical model. RESULTS: Metabolic changes were observed between pre- and postdata of each week and over the 3 weeks before the competition in the partial least-squares discriminant analysis. Creatine kinase concentration increased in the first 2 weeks (P = .045 and P = .039), but there was no difference in the last week (P > .05). Lactate levels increased significantly after training in each week (P < .001). Cortisol levels at Post3 were different from all other time points (P < .05) and the concentrations of peroxides increased over the weeks (P < .05). Among all metabolites, sarcosine showed the greatest differences (P = .004) in the pretraining and posttraining periods of the 3 weeks. CONCLUSION: Serum analysis of athletes using nuclear magnetic resonance showed metabolic changes depending on the intensity of the training performed each week.

Relationship of age at menarche and serum leptin with the metabolically unhealthy phenotype in adolescents / Relación de la edad de la menarquia y la leptina sérica con el fenotipo metabólicamente no saludable en adolescentes

OBJECTIVE: to analyze the relationship of age at menarche and leptin with the metabolically healthy (MH) and metabolically unhealthy (MUH) phenotypes in adolescent girls in different body mass index (BMI) categories. METHOD: an observational and cross-sectional study consisting of 139 female adolescents attended to at the Adolescent Reference Center in Macaé, Rio de Janeiro. Menarche was classified as early (EM) when the first menstruation occurred at or before 11 years of age; normal menarche (NM) was categorized at ages 12 to 14; menarche was considered late (LM) when it occurred at age 15 or older. The factors required to ascertain the subjects' phenotype, as well as their leptin levels, weight, and height, were measured and their BMIs were calculated. The girls were classified as MH or MUH based on the NCEP-ATP III criteria as adapted for children and adolescents. RESULTS: 82 % (n = 114) of the girls were classified as MH and 18 % (n = 25) as MUH. Mean age at menarche was 11.79 ± 1.39 years. There was a higher prevalence of MUH amongst the girls who had EM (p = 0.04). A higher inadequacy of serum leptin concentrations was found in girls who had EM (p = 0.05) and in those classified as MUH (p = 0.01). The adolescents who were severely obese exhibited inadequate leptin levels (p < 0.01) and had gone through EM (p = 0.02). A total of 8.1 % (n = 7) of the normal-weight girls were classified as MUH, and 29.4 % (n = 5) of those who were severely obese were classified as MH (p < 0.01). CONCLUSION: early menarche and high serum leptin concentrations are related with the MUH phenotype in adolescent girls in different BMI categories

OBJETIVO: analizar la relación de la edad de la menarquia y los niveles de leptina con los fenotipos metabólicamente saludables (MS) y metabólicamente no saludables (MNS) en adolescentes de diferentes categorías de índice de masa corporal (IMC). MÉTODO: estudio observacional y transversal compuesto por 139 adolescentes de sexo feminino, atendidas en el Centro de Referencia para Adolescentes de Macaé, Río de Janeiro. La menarquia se clasificó como precoz (MP) cuando se produjo la primera menstruación a o antes de los 11 años de edad; la menarquia normal (MN) se clasificó como aquella sucedida a la edad de 12 a 14 años; la menarquia se consideró tardía (MT) cuando ocurrió a los 15 años o más. Se midieron los factores necesarios para determinar el fenotipo de los sujetos, y se midieron sus niveles de leptina, peso y altura, y se calculó su IMC. Las adolescentes se clasificaron como MS y MNS según los criterios de NCEP-ATP III, adaptados para niños y adolescentes. RESULTADOS: el 82 % (n = 114) de las adolescentes se clasificaron como MH y el 18 % (n = 25) como MUH. La edad media de la menarquia fue de 11,79 ± 1,39 años. Hubo una mayor prevalencia de MUH entre las adolescentes que tenían MP (p = 0,04). Se encontró una mayor insuficiencia de las concentraciones séricas de leptina en las adolescentes que tenían MP (p = 0,05) y en aquellas clasificadas como MNS (p = 0,01). Las adolescentes que eran severamente obesas exhibieron niveles inadecuados de leptina (p < 0,01) y habían pasado por una MP (p = 0,02). El 8,1 % (n = 7) de las adolescentes de peso normal se clasificaron como MNS y el 29,4 % (n = 5) de las que eran severamente obesas se clasificaron como MS (p < 0,01). CONCLUSIÓN: la menarquia temprana y las altas concentraciones séricas de leptina están relacionadas con el fenotipo MNS en las adolescentes de diferentes categorías de IMC

Predictive equations for resting metabolic rate are not appropriate to use in Brazilian male adolescent football athletes.

High accuracy in estimating energy expenditure is essential for enhancing sports performance. The resting metabolic rate (RMR), as a primary component of total energy expenditure (TEE), is commonly estimated using predictive equations. However, these references may not be applicable to adolescent athletes. The purpose of this cross-sectional study was to analyse the differences between predicted RMR in relation to energy expenditure measured by indirect calorimetry (IC) among 45 Brazilian male adolescent football athletes. Indirect calorimetry (IC) and anthropometric (bioimpedance) measurements were recorded at a single visit to the laboratory after fasting overnight. The mean age was 15.6 ± 1.14 years, body mass was 63.05 ± 7.8 kg, and height was 172 ± 7.5 cm. The RMR values predicted by equations proposed by the Food and Agriculture Organization (FAO) (United Nations), Henry and Rees (HR), Harris Benedict (HB), and Cunningham (CUN) were compared with IC RMR values, by correlation analysis. The FAO and HR predictive equations yielded different values from IC (IC: 1716.26 ± 202.58, HR: 1864.87 ± 147.78, FAO: 1854.28 ± 130.19, p = 0.001). A moderate correlation of 0.504 was found between the results of HB and IC. In the survival-agreement model, the CUN equation showed low disagreement with the IC RMR, with error values between 200 and 300 kcal/day. The results showed that HB and CUN yielded similar values as IC, with the CUN equation showing low disagreement with IC; hence, adolescent athletes should undergo evaluation with precise laboratory methods to ensure that accurate information about RMR is recorded.

Relationship of age at menarche and serum leptin with the metabolically unhealthy phenotype in adolescents.

INTRODUCTION: Objective: to analyze the relationship of age at menarche and leptin with the metabolically healthy (MH) and metabolically unhealthy (MUH) phenotypes in adolescent girls in different body mass index (BMI) categories. Method: an observational and cross-sectional study consisting of 139 female adolescents attended to at the Adolescent Reference Center in Macaé, Rio de Janeiro. Menarche was classified as early (EM) when the first menstruation occurred at or before 11 years of age; normal menarche (NM) was categorized at ages 12 to 14; menarche was considered late (LM) when it occurred at age 15 or older. The factors required to ascertain the subjects' phenotype, as well as their leptin levels, weight, and height, were measured and their BMIs were calculated. The girls were classified as MH or MUH based on the NCEP-ATP III criteria as adapted for children and adolescents. Results: 82 % (n = 114) of the girls were classified as MH and 18 % (n = 25) as MUH. Mean age at menarche was 11.79 ± 1.39 years. There was a higher prevalence of MUH amongst the girls who had EM (p = 0.04). A higher inadequacy of serum leptin concentrations was found in girls who had EM (p = 0.05) and in those classified as MUH (p = 0.01). The adolescents who were severely obese exhibited inadequate leptin levels (p < 0.01) and had gone through EM (p = 0.02). A total of 8.1 % (n = 7) of the normal-weight girls were classified as MUH, and 29.4 % (n = 5) of those who were severely obese were classified as MH (p < 0.01). Conclusion: early menarche and high serum leptin concentrations are related with the MUH phenotype in adolescent girls in different BMI categories.

INTRODUCCIÓN: Objetivo: analizar la relación de la edad de la menarquia y los niveles de leptina con los fenotipos metabólicamente saludables (MS) y metabólicamente no saludables (MNS) en adolescentes de diferentes categorías de índice de masa corporal (IMC). Método: estudio observacional y transversal compuesto por 139 adolescentes de sexo feminino, atendidas en el Centro de Referencia para Adolescentes de Macaé, Río de Janeiro. La menarquia se clasificó como precoz (MP) cuando se produjo la primera menstruación a o antes de los 11 años de edad; la menarquia normal (MN) se clasificó como aquella sucedida a la edad de 12 a 14 años; la menarquia se consideró tardía (MT) cuando ocurrió a los 15 años o más. Se midieron los factores necesarios para determinar el fenotipo de los sujetos, y se midieron sus niveles de leptina, peso y altura, y se calculó su IMC. Las adolescentes se clasificaron como MS y MNS según los criterios de NCEP-ATP III, adaptados para niños y adolescentes. Resultados: el 82 % (n = 114) de las adolescentes se clasificaron como MH y el 18 % (n = 25) como MUH. La edad media de la menarquia fue de 11,79 ± 1,39 años. Hubo una mayor prevalencia de MUH entre las adolescentes que tenían MP (p = 0,04). Se encontró una mayor insuficiencia de las concentraciones séricas de leptina en las adolescentes que tenían MP (p = 0,05) y en aquellas clasificadas como MNS (p = 0,01). Las adolescentes que eran severamente obesas exhibieron niveles inadecuados de leptina (p < 0,01) y habían pasado por una MP (p = 0,02). El 8,1 % (n = 7) de las adolescentes de peso normal se clasificaron como MNS y el 29,4 % (n = 5) de las que eran severamente obesas se clasificaron como MS (p < 0,01). Conclusión: la menarquia temprana y las altas concentraciones séricas de leptina están relacionadas con el fenotipo MNS en las adolescentes de diferentes categorías de IMC.

Caffeine Supplementation for 4 Days Does Not Induce Tolerance to the Ergogenic Effects Promoted by Acute Intake on Physiological, Metabolic, and Performance Parameters of Cyclists: A Randomized, Double-Blind, Crossover, Placebo-Controlled Study.

The present study investigated whether the caffeine supplementation for four days would induce tolerance to the ergogenic effects promoted by acute intake on physiological, metabolic, and performance parameters of cyclists. A double-blind placebo-controlled cross-over design was employed, involving four experimental trials; placebo (4-day)-placebo (acute)/PP, placebo (4-day)-caffeine (acute)/PC, caffeine (4-day)-caffeine (acute)/CC and caffeine (4-day)-placebo (acute)/CP. Fourteen male recreationally-trained cyclists ingested capsules containing either placebo or caffeine (6 mg∙kg-1) for 4 days. On day 5 (acute), capsules containing placebo or caffeine (6 mg∙kg-1) were ingested 60 min before completing a 16 km time-trial (TT). CC and PC showed improvements in time (3.54%, ES = 0.72; 2.53%, ES = 0.51) and in output power (2.85%, ES = 0.25; 2.53%, ES = 0.20) (p < 0.05) compared to CP and PP conditions, respectively. These effects were accompanied by increased heart rate (2.63%, ES = 0.47; 1.99%, ES = 0.34), minute volume (13.11%, ES = 0.61; 16.32%, ES = 0.75), expired O2 fraction (3.29%, ES = 0.96; 2.87, ES = 0.72), lactate blood concentration (immediately after, 29.51% ES = 0.78; 28.21% ES = 0.73 recovery (10 min), 36.01% ES = 0.84; 31.22% ES = 0.81), and reduction in expired CO2 fraction (7.64%, ES = 0.64; 7.75%, ES = 0.56). In conclusion, these results indicate that caffeine, when ingested by cyclists in a dose of 6 mg∙kg-1 for 4 days, does not induce tolerance to the ergogenic effects promoted by acute intake on physiological, metabolic, and performance parameters.

Protein Oxidation in Plant Protein-Based Fibrous Products: Effects of Encapsulated Iron and Process Conditions.

Plant protein-based fibrous structures have recently attracted attention because of their potential as meat replacer formulations. It is, however, unclear how the process conditions and fortification with micronutrients may affect the chemical stability of such products. Therefore, we aimed to investigate the effects of process conditions and the incorporation of iron (free and encapsulated) on protein oxidation in a soy protein-based fibrous product. First, the physicochemical stability of iron-loaded pea protein particles, used as encapsulation systems, was investigated when exposed to 100 or 140 °C. Second, protein oxidation was measured in the iron-fortified soy protein-based fibrous structures made at 100 or 140 °C. Exposure to high temperatures increased the carbonyl content in pea protein particles. The incorporation of iron (free or encapsulated) did not affect carbonyl content in the fibrous product, but the process conditions for making such products induced the formation of carbonyls to a fairly high extent.

Intense physical exercise potentiates glucose inhibitory effect over food intake of male Wistar rats.

NEW FINDINGS: What is the central question of this study? How does an acute session of exercise affect food intake of male Wistar rats? What is the main finding and its importance? Food intake in male Wistar rats is decreased in the first hour after physical exercise independent of the intensity. Moreover, high-intensity exercise potentiates the anorexic effect of peripheral glucose administration. This work raises new feeding-related targets that would explain how exercise drives body weight loss. ABSTRACT: Obesity has emerged as a critical metabolic disorder in modern society. An adequate lifestyle with a well-oriented programme of diet and physical exercise (PE) can prevent or potentially even cure obesity. Additionally, PE might lead to weight loss by increasing energy expenditure and decreasing hunger perception. In this article, we hypothesize that an acute exercise session would potentiate the glucose inhibitory effects on food intake in male Wistar rats. Our data show that moderate- or high-intensity PE significantly decreased food intake, although no changes in the expression of feeding-related neuropeptide in the arcuate nucleus of the hypothalamus were found. Exercised animals demonstrated a reduced glucose tolerance and increased blood insulin concentration. Intraperitoneal administration of glucose decreased food intake in control animals. In the animals submitted to moderate-intensity PE, the decrease in food intake promoted by glucose was similar to controls; however, an interaction was observed when glucose was injected in the high-intensity PE group, in which food intake was significantly lower than the effect produced by glucose alone. A different pattern of expression was observed for the monocarboxylate transporter isoforms (MCT1, 2 and 4) and 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFBP3) in the hypothalamus, which was dependent on the exercise intensity. In conclusion, PE decreases food intake independently of the intensity. However, an interaction between PE and the anorexic effect of glucose is only observed when a high-intensity exercise is performed. These data show an essential role of exercise intensity in the modulation of the glucose inhibitory effect on food intake.

Validity of Skinfold Equations, Against Dual-Energy X-Ray Absorptiometry, in Predicting Body Composition in Adolescent Pentathletes.

PURPOSE: Body composition of adolescent athletes is often evaluated scientifically and in sports by using reference equations developed from nonathlete adolescent populations. The aim of this study was to analyze the validity of predictive equations based on skinfold measurements, as compared with dual-energy X-ray absorptiometry (DXA), to estimate body fat in adolescent modern pentathlon athletes. METHODS: 51 athletes, 27 male (mean age = 15.1 years; standard deviation, SD = 1.5 years) and 24 female (mean age = 14.2 years; SD = 2.5 years), were assessed using DXA, anthropometric parameters, sports practice anamnesis, and pubertal stages. Agreement between methods was tested with boxplots of mean comparisons using Student's t test (p < .05), and Bland-Altman plots. RESULTS: The body density equations of Durnin & Rahaman (1967) and Durnin & Womersley (1974) showed better agreement with DXA than the other predictive equations, for both females (difference between means=-2.03; 2SD = 8.44) and males (difference between means = 0.98; 2SD = 7.30). There were no mean differences between these equations and the reference method (DXA; p > .05), but they did display high variability (2SD). CONCLUSION: The high variability among results indicated imprecision. Predictive skinfold equations developed for nonathlete adolescents do not offer good validity for modern adolescent pentathlon athletes, and should be avoided.

Critical evaluation of food intake and energy balance in young modern pentathlon athletes: a cross-sectional study.

BACKGROUND: Modern pentathlon comprises five sports: fencing, swimming, equestrian jumping, and a combined event of pistol shooting and running. Despite the expected high energy demand of this sport, there are few studies that provide support for the nutritional recommendations for pentathletes. The purpose of the present study was to evaluate young modern pentathlon athletes with respect to body composition, biochemical profile, and consumption of food and supplements. METHODS: Fifty-six young modern pentathletes aged 13.5 ± 2.4 years participated in the study: 22 adolescent girls and 34 adolescent boys, weight 55.8 ± 13.3 kg, height 1.6 ± 0.1 m, and body fat 21.1 ± 3.1 %. Food consumption was analyzed through a 24-h recall method and food-frequency questionnaire. Assessment of body composition was carried out by checking anthropometric measures (body mass, height, and skinfolds) and using protocols according to participants' age and sexual maturity. RESULTS: Male participants consumed less energy than the general recommendations for athletes from the American Dietetic Association (2749 ± 1024 kcal vs. 3113 ± 704 kcal, p < 0.01), whereas female participants consumed more energy than those recommendations (2558 ± 808 kcal vs. 2213 ± 4734 kcal, p < 0.01). Neither young men nor young women followed the carbohydrate intake recommendations for athletes (6.3 ± 2.5 g/kg/day and 6.6 ± 2.2 g/kg/day, respectively). Lipid and protein intakes corresponded to recommendations for both sexes; however, insufficient intakes of calcium, fruits, and vegetables were seen, as well as frequent consumption of baked goods and sugared soft drinks. CONCLUSIONS: Adolescent modern pentathlon athletes presented inadequate eating habits with respect to consumption of carbohydrates and energy. Many participants had insufficient intake of micronutrients, especially calcium. However, future research is needed that is aimed at elucidating the real nutritional demands for good physical performance in this sport and the impact of inadequate eating habits on performance, especially among young athletes who are in the growth-stage years and are exposed to intense physical exercise routines.

Development of a beetroot-based nutritional gel containing high content of bioaccessible dietary nitrate and antioxidants.

Beetroot, a food rich in nitrate and antioxidants has gained attention because of its potential effect on improving cardiovascular health and exercise performance. This work had the purpose of developing a beetroot-based nutritional gel (BG) and estimating the in vitro bioaccessibility of the nitrate, total antioxidant capacity (TAC), total phenolic (TP) and potassium content, as compared to beetroot juice (BJ). Nitrate was assessed by a high-performance liquid chromatography system, TAC was assessed using the Trolox equivalent antioxidant capacity (TEAC) assay and TP was measured using the Folin-Ciocalteu method before and after an in vitro digestion. Significantly higher values of nitrate, TEAC, TP and potassium before and after digestion were observed in BG as compared to BJ. The results suggest a new nutritional strategy to give high contents of bioaccessible nutrients (nitrate, antioxidants and potassium) that are potentially relevant to improve cardiovascular health and exercise performance.

Physicochemical, nutritional, and sensory analyses of a nitrate-enriched beetroot gel and its effects on plasmatic nitric oxide and blood pressure.

BACKGROUND: Beetroot (Beta vulgaris L.) is a dietary source of natural antioxidants and inorganic nitrate (NO3(-)). It is well known that the content of antioxidant compounds and inorganic nitrate in beetroot can reduce blood pressure (BP) and the risk of adverse cardiovascular effects. OBJECTIVE: The aim of the present study was to formulate a beetroot gel to supplement dietary nitrate and antioxidant compounds able to cause beneficial health effects following acute administration. DESIGN AND SUBJECTS: A beetroot juice produced from Beta vulgaris L., without any chemical additives, was used. The juice was evaluated by physicochemical and microbiological parameters. The sample was tested in five healthy subjects (four males and one female), ingesting 100 g of beetroot gel. RESULTS: The formulated gel was nitrate enriched and contained carbohydrates, fibers, saponins, and phenolic compounds. The formulated gels possess high total antioxidant activity and showed adequate rheological properties, such as high viscosity and pleasant texture. The consumer acceptance test for flavor, texture, and overall acceptability of beetroot gel flavorized with synthetic orange flavor had a sensory quality score >6.6. The effects of acute inorganic nitrate supplementation on nitric oxide production and BP of five healthy subjects were evaluated. The consumption of beetroot gel increased plasma nitrite threefold after 60 min of ingestion and decreased systolic BP (-6.2 mm Hg), diastolic BP (-5.2 mm Hg), and heart rate (-7 bpm).

Comparison of total antioxidant potential, and total phenolic, nitrate, sugar, and organic acid contents in beetroot juice, chips, powder, and cooked beetroot.

Beetroot is a vegetable rich in nitrate (NO3 -), antioxidants and phenolic compounds that are related to improvements in cardiovascular function and exercise performance. However, it is unknown if convenient forms of beetroot administration provide different amounts of these nutrients. The total antioxidant potential (TAP), total phenolic (TPC), sugar, organic acid, and NO3 - contents of beetroot juice (BJ), chips (BC), powder (BP), and cooked beetroot (CB) were compared. Significant (p<0.01) differences in chemical compositions and functional properties were found between beetroot formulations. Higher amounts of TAP and organic acids were observed in BC and BP, compared with the other formulations. BJ exhibited the highest contents of total sugars, TPC, and NO3 -. All beetroot formulations were suitable and advantageous based on taste preferences and convenience for consumers and for nutrient amounts required to meet dietary recommendations.