Nutritional supplements in Norwegian elite athletes--impact of international ranking and advisors

Prevalence of supplement usage and related attitudes and reasons among fitness athletes in the gyms of Kashan and its relationship with feeding behavior: a cross-sectional study

BACKGROUND

The overuse of supplements among athletes is a widespread issue affecting the health of both male and female athletes. However, research on supplements usage among female fitness athletes is limited, and there is little information on the feeding behavior of fitness athletes who use supplements. This study aimed to fill the gap in knowledge by examining the prevalence of supplement usage and its related attitudes and reasons among fitness athletes in the gyms of Kashan. It further aimed to investigate the correlation between supplements usage and the feeding behavior of fitness athletes.

METHODS

For these purposes, in this cross-sectional study, 433 fitness athletes (15‒46 years old) in 28 gyms in the city of Kashan were surveyed using a researcher-made questionnaire in 2023. Five experts confirmed the validity of the questionnaire. The present study considered the supplements based on the Australian Institute of Sport position statement. A Chi-square analysis was conducted to examine the relationship between the study variables and supplement usage.

RESULTS

Overall, 272 male and 161 female fitness athletes participated in this study. The results revealed that 57.9% of participants used supplements, most commonly vitamin C, vitamin D, omega-3 fatty acids, and whey protein. The main reason for using supplements was to speed up body repair after exercise (69.5%). Additionally, 41.8% of these athletes believed that using supplements improves their overall performance, and 21.9% thought that supplements do not harm the body. Moreover, a correlation was observed between feeding behavior and the consumption of supplements. It was found that athletes who use supplements tend to eat more white meat, seeds, and nuts and fewer high-fat dairy products than those who do not consume them.

CONCLUSION

Using supplements among fitness athletes in the gyms of Kashan is common. The main reason for using these substances was to speed up body repair after exercise, and nearly half of the athletes believed that supplements improved their performance. In addition, it was revealed that athletes who take supplements have healthier feeding behaviors than those who do not. Thus, these findings confirm the necessity of informing fitness athletes about using supplements.

Short-Term Panax Ginseng Extract Supplementation Reduces Fasting Blood Triacylglycerides and Oxygen Consumption during Sub-Maximal Aerobic Exercise in Male Recreational Athletes

Ginseng, a popular herbal supplement among athletes, is believed to enhance exercise capacity and performance. This study investigated the short-term effects of Panax ginseng extract (PG) on aerobic capacity, lipid profile, and cytokines. In a 14-day randomized, double-blind trial, male participants took 500 mg of PG daily. Two experiments were conducted: one in 10 km races (n = 31) and another in a laboratory-controlled aerobic capacity test (n = 20). Blood lipid and cytokine profile, ventilation, oxygen consumption, hemodynamic and fatigue parameters, and race time were evaluated. PG supplementation led to reduced total blood lipid levels, particularly in triacylglycerides (10 km races -7.5 mg/dL (95% CI -42 to 28); sub-maximal aerobic test -14.2 mg/dL (95% CI -52 to 23)), while post-exercise blood IL-10 levels were increased (10 km 34.0 pg/mL (95% CI -2.1 to 70.1); sub-maximal aerobic test 4.1 pg/mL (95% CI -2.8 to 11.0)), and oxygen consumption decreased during the sub-maximal aerobic test (VO2: -1.4 mL/min/kg (95% CI -5.8 to -0.6)). No significant differences were noted in race time, hemodynamic, or fatigue parameters. Overall, PG supplementation for 2 weeks showed benefits in blood lipid profile and energy consumption during exercise among recreational athletes. This suggests a potential role for PG in enhancing exercise performance and metabolic health in this population.

Use of Buffers in Specific Contexts: Highly Trained Female Athletes, Extreme Environments and Combined Buffering Agents-A Narrative Review

This narrative review evaluated the evidence for buffering agents (sodium bicarbonate, sodium citrate and beta-alanine), with specific consideration of three discrete scenarios: female athletes, extreme environments and combined buffering agents. Studies were screened according to exclusion and inclusion criteria and were analysed on three levels: (1) moderating variables (supplement dose and timing, and exercise test duration and intensity), (2) design factors (e.g., use of crossover or matched group study design, familiarisation trials) and (3) athlete-specific factors (recruitment of highly trained participants, buffering capacity and reported performance improvements). Only 19% of the included studies for the three buffering agents reported a performance benefit, and only 10% recruited highly trained athletes. This low transferability of research findings to athletes' real-world practices may be due to factors including the small number of sodium citrate studies in females (n = 2), no studies controlling for the menstrual cycle (MC) or menstrual status using methods described in recently established frameworks, and the limited number of beta-alanine studies using performance tests replicating real-world performance efforts (n = 3). We recommend further research into buffering agents in highly trained female athletes that control or account for the MC, studies that replicate the demands of athletes' heat and altitude camps, and investigations of highly trained athletes' use of combined buffering agents. In a practical context, we recommend developing evidence-based buffering protocols for individual athletes which feature co-supplementation with other evidence-based products, reduce the likelihood of side-effects, and optimise key moderating factors: supplement dose and timing, and exercise duration and intensity.

Trends in dietary supplement use among athletes selected for doping controls

Background

Dietary supplements (DS) may be beneficial for athletes in certain situations, whereas incorrect or excessive use may impair performance, pose a risk to the athlete's health and cause positive doping tests by containing prohibited substances. To provide athletes with relevant and tailored information on safe supplement use, a better knowledge about DS trends over time and between sport disciplines are needed.

Methods

This study examines the use of DS among athletes who have participated in doping controls by extracting information derived from 10,418 doping control forms (DCF) collected by Anti-Doping Norway from 2015 to 2019.

Results

Overall, 51% of the DCFs contained information about at least one DS. National level athletes (NLA) more often reported using DS than recreational athletes (RA) (53 vs. 47%, p < 0.001). Athletes in strength and power (71%), VO2max endurance (56%) and muscular endurance sports (55%) had the highest proportion of DCFs with information about DS. Medical supplements were the most used supplement category for both genders and across all sports. Dietary supplements with a high risk of containing doping substances were most common among male, RA in strength and power sports. There were small and non-significant year-to-year variations in the prevalence of athletes using DS, while the number of products used concomitantly peaked in 2017 before declining in 2019 (2.30 vs. 2.08, p < 0.01). The use of medical supplements and ergogenic substances increased slightly for both NLA and RA from 2015 to 2019, while the use of all other supplement categories declined.

Conclusion

Half of the 10,418 DCFs contained information about DS, with variations within the athlete population. DS with high risk of containing prohibited substances were mostly seen in sport disciplines requiring a high degree of specialization in strength/power, including powerlifting and weightlifting, as well as in some team sports, such as cheerleading and american football.

Dietary Supplements Use among Athletes in Lebanon: Knowledge, Attitudes, Practices, and Correlates

Athletes are under the utmost pressure to reach excellence in their performance and achieve the desired outcomes in competitions, prompting them to use dietary supplements. Given the threats to both health and eligibility, it is crucial to observe the prevalence, sources of information, knowledge, attitudes, and practices (KAPs) among Lebanese athletes practicing their sports for at least two years. In the present paper, a cross-sectional study is performed using the snowball sampling method, in which a self-administered KAP questionnaire is used to collect data from 455 athletes (mean age: 27.4 ± 7.9 years; men: 73.1%) participating in four sports categories (ball games, combat sports, endurance sports, and weightlifting). Among the Lebanese athletes, the prevalence of dietary supplement (DS) use was 74%, where half of them had predominately used sports supplements. Athletes in Lebanon heavily rely on coaches (74%) and online sources, including webpages and social media (64%), as key information sources for DSs. The findings suggest that significant proportions of athletes show knowledge deficits and unsatisfactory attitudes towards multiple aspects related to supplementation. Moreover, education and sports type modulate the use of DSs among athletes. Furthermore, 34% reported using supplements without a recommendation from specialists, and 69% admitted to not reading the supplement's nutrition facts. This study urges the need for the regulation of concerned authorities and education programs to help overcome the existing challenges.

The Prevalence of Dietary Supplement Usage in Military Aviators

Background: The prevalence of dietary supplement (DS) and energy drink (ED) usage in military personnel differs from branch to branch and is between 55% and 76% (higher values in special operations forces). Aviators with highly demanding tasks might be especially interested in using dietary supplements. To date, there are only limited data available for this special profession inside the military. Methods: An internet-based survey was conducted on the prevalence of DS and ED usage, the reasons for their usage and the place of purchase for all wings of the German Armed Forces. Results: Of the 181 pilots who participated in the survey, 34% used DSs and 16% EDs. Usage was linked to sports activities but not to the type of aircraft. DSs were purchased on the internet by 50% of the respondents; mostly protein supplements, magnesium and omega-3fatty acids. Only 42% said they would feel an effect from taking DSs. Conclusions: Although the present study showed that the prevalence of usage was comparable to that of the civilian population, the sources of supply and the range of the substances taken give cause for concern. This calls for education and information campaigns to make the pilots aware of the possible risks to their health.

Panax ginseng Supplementation Increases Muscle Recruitment, Attenuates Perceived Effort, and Accelerates Muscle Force Recovery After an Eccentric-Based Exercise in Athletes

ABSTRACT

Cristina-Souza, G, Santos-Mariano, AC, Lima-Silva, AE, Costa, PL, Domingos, PR, Silva, SF, Abreu, WC, De-Oliveira, FR, and Osiecki, R. Panax Ginseng supplementation increases muscle recruitment, attenuates perceived effort, and accelerates muscle force recovery after an eccentric-based exercise in athletes. J Strength Cond Res 36(4): 991-997, 2022-The effect of Panax ginseng during and after an eccentric-based exercise is underexplored. In this study, we investigated the effect of Panax ginseng on muscle force and muscle excitation during an eccentric-based exercise and on subsequent muscle damage and delayed-onset muscle soreness (DOMS). Using a randomized, double-blind, crossover design, 10 male track and field athletes consumed Panax ginseng or placebo for 8 days. At the fifth day, they performed 4 sets until concentric failure of a half-squat exercise, with eccentric action increased by using an eccentric-inductor device attached to their knees. The rating of perceived exertion (RPE) and vastus lateralis electromyographic (EMG) activity was measured during the half-squat. Plasma lactate dehydrogenase (LDH) and creatine kinase (CK) concentrations, DOMS, and maximal isometric voluntary contractions (MIVCs) with EMG recording were measured at 24, 48, and 72 hours after the half-squat. Panax ginseng attenuated RPE and increased EMG during the sets. The MIVC remained reduced 48 hours after exercise in the placebo but returned to baseline 24 hours after exercise in the Panax ginseng, with values at 24 and 48 hours after exercise significantly higher in the Panax ginseng than in the placebo. The EMG during MIVC was higher in the Panax ginseng than in the placebo over the time points. No significant effect of Panax ginseng on LDH, CK, and DOMS was observed. These findings suggest that Panax ginseng increases muscle excitation and attenuates perceived effort during an eccentric-based exercise as well as accelerates the recovery of muscle force in well-trained athletes.

Bodybuilding, dietary supplements and hormones use: behaviour and determinant analysis in young bodybuilders

BACKGROUND

Among athletes, bodybuilders are more predisposed to the use of dietary supplements (DS) and hormones (H) to increase in adaptations to physical training and performance. The purpose of the study was to identify social, psychological, and organisational factors that are associated with the use of food supplements and hormones in young bodybuilders of the metropolitan area of Naples.

METHODS

107 athletes, practicing bodybuilding, were consecutively recruited in 30 gyms, randomly selected in the metropolitan area of Naples. Athletes were administered an anonymous questionnaire. The questionnaire consists of 5 sections (socio-demographic, frequency and reasons for bodybuilding, knowledge, attitudes and behaviours). Descriptive statistics were performed using T-test and Chi-square statistics. A score was created for knowledge, attitudes, behaviours. Multivariable logistic regression models were employed to assess association between each score and the use of DS and H. Statistical analyses were carried out using STATA 15.

RESULTS

81.31% of the subjects reported to use DS while 35.51% H. Females are less likely to practise bodybuilding frequently than males (OR 0.18 (95% CI 0.05-0.69), p = 0.01). Subjects who have attended high school or university have a lower probability of taking DS (OR 0.17 (95% CI 0.04-0.65), p = 0.01). H users also use supplements more frequently (OR 61.21 (95% CI 3.99-939.31), p < 0.001). Those who scored higher on knowledge scores are more likely to take DS (OR 1.53 (95% CI 1.11-2.12), p < 0.001). Attitudes are correlated with the use of DS; those who scored higher were less likely to use DS (OR 0.77 (95% CI 0.30-0.98), p = 0.03). People who use DS are 30 times more likely to use H at the same time (OR 30.25 (95% CI 2.51-365.24), p < 0.001). Subjects who have a higher score for knowledge and attitudes are less likely to use H (OR 0.68 (95% CI 0.54-0.87), p < 0.001, OR 0.75 (95% CI 0.62-0.90), p < 0.001).

CONCLUSIONS

Prevalence of H and DS' use, although lower than reported in the literature, is a worrying public health problem. Better knowledge can lead to an informed use. Gym instructors should be trained to provide accurate and scientifically sound information. Health professionals should combine their expertise to provide more comprehensive guidance to the exercisers.

Protein, Creatine, and Dieting Supplements Among Adolescents: Use and Associations With Eating Disorder Risk Factors, Exercise-, and Sports Participation, and Immigrant Status

Objective: This study aimed to estimate the number of weekly users of protein, creatine, and dieting supplements and to explore whether weekly use was related to eating disorder (ED) risk factors, exercise, sports participation, and immigrant status.

Methods: In total, 629 and 1,060 high school boys and girls, respectively, self-reported weekly frequency of protein, creatine, and dieting supplement use, and weight and shape concerns, appearance internalization and pressure, self-esteem, mental distress, physical activity level, exercise context, and the type and weekly frequency of sport played. Multiple hierarchical regression analyses were performed to investigate explanatory factors for supplement use.

Results: More boys than girls used protein and creatine supplements. Immigrant boys had more frequent use of all supplements than non-immigrant boys, and immigrant girls used creatine supplements more frequently than non-immigrant girls. In total, 23–40 and 5–6% of the variation in the weekly frequency of supplement use in boys and girls, respectively, was explained by immigrant status, ED risk factors, and exercise and sports participation. More frequent use of protein, creatine and dieting supplements in boys was significantly explained by more weight and shape concerns, fitness center exercise, and weight-sensitive sports participation. Depending on the type of supplement, more frequent use of supplements in girls was significantly explained by lower self-esteem, more engagement in weight-sensitive sports, and less engagement in general sport and exercise activities.

Conclusion: Weekly supplement use was common and more frequent among boys than girls. The weekly use of protein, creatine, and dieting supplements was related to ED risk factors, exercise and sports participation, and immigrant status in boys but not in girls.

Supplement intake in half-marathon, (ultra-)marathon and 10-km runners - results from the NURMI study (Step 2)

The primary nutritional challenge facing endurance runners is meeting the nutrient requirements necessary to optimize the performance and recovery of prolonged training sessions. Supplement intake is a commonly used strategy by elite and recreational distance runners to meet nutritional recommendations. This study was conducted to investigate the patterns of supplement intake among different groups of distance runners and the potential association between supplement intake and sex, age, running and racing experiences.In a cross-sectional design, from a total of 317 runners participating in this survey, 119 distance runners were involved in the final sample after data clearance, assigned into three groups of 10-km runners (n = 24), half-marathoners (n = 44), and (ultra-)marathoners (n = 51). Personal characteristics, training and racing experiences, as well as patterns of supplement intake, including type, frequency, and dosage, were evaluated by questionnaire. Food Frequency Questionnaire was implemented to assess macronutrient intake. ANOVA and logistic regression were used for statistical analysis.While 50 % of total distance runners reported consuming supplements regularly, no differences between distance groups in consumption of carbohydrate/protein, mineral, or vitamin supplements were observed (p > 0.05). In addition, age, sex, running and racing experience showed no significant association with supplement intake (p > 0.05). Vitamin supplements had the highest intake rate in runners by 43 % compared to minerals (34 %) and carbohydrate/protein supplements (19 %).The present findings provide a window into the targeted approaches of long-distance runners as well as their coaches and sport nutrition specialists when applying and suggesting sustainable nutritional strategies for training and competition.Trial registration: ISRCTN73074080. Retrospectively registered 12th June 2015.

Sex Differences in Supplement Intake in Recreational Endurance Runners-Results from the NURMI Study (Step 2)

It has been well-documented that female and male athletes differ in many physiological and psychological characteristics related to endurance performance. This sex-based difference appears to be associated with their nutritional demands including the patterns of supplement intake. However, there is a paucity of research addressing the sex differences in supplement intake amongst distance runners. The present study aimed to investigate and compare supplement intake between female and male distance runners (10 km, half-marathon, (ultra-)marathon) and the potential associations with diet type and race distance. A total of 317 runners participated in an online survey, and 220 distance runners (127 females and 93 males) made up the final sample after a multi-stage data clearance. Participants were also assigned to dietary (omnivorous, vegetarian, vegan) and race distance (10-km, half-marathon, marathon/ultra-marathon) subgroups. Sociodemographic characteristics and the patterns of supplement intake including type, frequency, dosage, and brands were collected using a questionnaire. One-way ANOVA and logistic regression were used for data analysis. A total of 54.3% of female runners and 47.3% male runners reported consuming supplements regularly. The frequency of supplement intake was similar between females and males (generally or across dietary and distance subgroups). There was no significant relationship for sex alone or sex interactions with diet type and race distance on supplement intake (p < 0.05). However, a non-significant higher intake of vitamin and mineral (but not CHO/protein) supplements was reported by vegan and vegetarian (but not by omnivorous) females compared to their male counterparts. In summary, despite the reported findings, sex could not be considered as a strong modulator of supplement intake among different groups of endurance runners.

Nutritional Values of Foods on a Population of the Czech Republic

The aim of this text is to present the results of the research we carried out on a group of inhabitants of the Czech Republic who actively (or at least occasionally) engage in sports activities. The aim of the research was to analyse the consumer behavior of athletes in the Czech Republic with an emphasis on their use of health food stores and their habits in monitoring the nutritional values of food, in the content of sugar and carbohydrates in the food they consume. Excess sugar consumption; obesity; and, conversely, the issue of a healthy lifestyle and the growing interest in healthy “alternative” lifestyles, have often been a subject of debate. The research has shown, among other things, that 58% of respondents consume sugar; 70% of men and 88% of women shop at health food stores at least occasionally; and the most monitored values are calories, carbohydrates, and sugar.

Dietary supplements usage by elite female football players: an exploration of current practices

The present study aimed to investigate the prevalence of dietary supplements usage (types, reasons for usage, sources of information, purchase venues) among elite female football players, using a self-administered questionnaire. The study participants (n = 103) were recruited through team physicians during an official international tournament. Overall, 82% reported using dietary supplements at least once during the last 12 months. The most common dietary supplements were vitamin D (52%), omega-3 fatty acids (49%), and protein (45%). Primary reasons for dietary supplement use were to stay healthy (66%), to accelerate recovery (58%), and to increase energy/reduce fatigue (54%). Supplement advice came mainly from medical doctors (46%), dietitians/nutritionists (43%), and coaches/fitness coaches (41%). Most dietary supplements were acquired from supplement stores (30%), a sponsor (26%), or drugstores/pharmacies (22%). Elite female football players are frequent dietary supplement users. Further research needs to explore the frequency, dose, and timing of these supplements.

Dietary Supplement Use According to Sex and Triad Risk Factors in Collegiate Endurance Runners

ABSTRACT

Barrack, MT, Fredericson, M, Dizon, F, Tenforde, AS, Kim, BY, Kraus, E, Kussman, A, Singh, S, and Nattiv, A. Dietary supplement use according to sex and Triad risk factors in collegiate endurance runners. J Strength Cond Res 35(2): 404-410, 2021-This cross-sectional study evaluated the prevalence in the use of dietary supplements among elite collegiate runners among 2 NCAA Division I cross-country teams. At the start of each season from 2015 to 2017, male and female endurance runners were recruited to complete baseline study measures; the final sample included 135 (male n = 65, female n = 70) runners. Runners completed a health survey, web-based nutrition survey, and Triad risk assessment. The prevalence of dietary supplement use and Triad risk factors, including disordered eating, low bone mass, amenorrhea (in women), low body mass index, and stress fracture history, was assessed. A total of 78.5% (n = 106) runners reported taking 1 or more supplements on ≥4 days per week over the past month, 48% (n = 65) reported use of ≥3 supplements. Products used with highest frequency included multivitamin/minerals 46.7% (n = 63), iron 46.7% (n = 63), vitamin D 34.1% (n = 46), and calcium 33.3% (n = 45). More women, compared with men, used iron (61.4 vs. 30.8%, p < 0.001) and calcium (41.4 vs. 24.6%, p = 0.04); men exhibited higher use of amino acids and beta-alanine (6.2 vs. 0%, p = 0.04). Runners with bone stress injury (BSI) history, vs. no previous BSI, reported more frequent use of ≥3 supplements (61.5 vs. 32.8%, p = 0.001), vitamin D (49.2 vs. 19.4%, p < 0.001), and calcium (47.7 vs. 19.4%, p = 0.001). Low bone mineral density was also associated with higher use of vitamin D and calcium. Most runners reported regular use of 1 or more supplements, with patterns of use varying based on sex, history of BSI, and bone mass.

Use, Practices and Attitudes of Elite and Sub-Elite Athletes towards Tart Cherry Supplementation

Tart cherry (TC) supplementation can improve exercise recovery and performance; and may also improve sleep duration and quality. This study investigated the use and knowledge of TC supplementation by athletes of all competitive levels. Eighty participants (52.5% elite (international, national, professional), 47.5% sub-elite (semi-professional, state/regional, county level, club level, recreational)) completed an online questionnaire investigating their attitudes towards and use of TC supplementation. Overall, 22.6% of participants were using or had previously used TC supplements, and 12.5% of participants planned to used TC supplements. Improved recovery (71.4%), sleep (32.1%) and immunity and general health (32.1%) were the most frequently indicated goals by respondents using TC supplements. In total, 32.1% of respondents were supplemented with TC chronically, 39.3% acutely and 28.6% used a combination of chronic and acute supplementation. The majority of those employing TC supplementation chronically used TC either over 2-3 days (37.0%) or continuously (37.0%). The most popular TC pre- and post-loading period was one day (34.3% and 41.5%, respectively). There were no significant differences between elite and sub-elite athletes in any parameters assessed (p > 0.05). TC supplementation is not widely used by the athletes surveyed, and athletes using TC supplements showed poor awareness of an evidence-led dosing strategy, regardless of competitive level.

Prevalence of Supplement Consumption in Iranian Athletes: A Systematic Review and Meta-Analysis

Background:

Due to widespread use of supplement among athletes, determining the prevalence and pattern of dietary supplement consumption and its moderators will be a road map for developing a strategic planning in the national level to achieve healthy lifestyle and avoid harmful nutritional approaches.

Methods:

A systematic search of the electronic resources including Medline, PubMed, Scopus, Google Scholar and National Persian Databases including Magiran, SID, IranDoc and CIVILICA (between 1979 and November 2019 in Persian and English language) was accomplished. Inclusion criteria were (a) studies containing the prevalence rate of dietary supplement consumption, specifically (b) studies were conducted in athletes. Finally, 32 articles were included.

Results:

The prevalence rate of supplement use in overall Iranian athletic population was 64.8% (95% CI, 55.8%-73.8%) with significant heterogeneity (I² = 99.7%, P < 0.001). The prevalence rate was reported to be higher in male athletes, athletes aged 25 and older and elite athletes (P < 0.05). The most prevalent source of information about supplement use among athletes were trainers, followed by physicians, friends-teammates and dietitians.

Conclusions:

According to the high prevalence of supplement consumption among Iranian athletes, policy making for educational programs is mandated. Trainers are the most popular source to provide information about supplements and educational programs should be conducted for this target population.

Prevalence, knowledge and attitudes towards using sports supplements among young athletes

Background

The aim of this international study was to investigate the prevalence of the use of sports supplements among young athletes, as well as their knowledge and attitudes towards sports supplementation.

Methods

Organized survey study testing the level of knowledge, attitudes, beliefs and practices concerning the use of sports supplements was administered to 348 athletes, 15–18 year olds from 4 countries competing in 18 sports at the international level.

Results

The prevalence rate of the intake of sports supplements was 82.2%, with the protein supplements being predominant (54.5%). Coaches were identified as the primary source of information regarding supplementation (41.4%). The enhancement of athletic performance (35.4%) was the major motivation for the supplements intake. The majority of athletes (72.1%) were aware of associated health risks. The young athletes possess varying levels of knowledge regarding their own supplementation. The obtained data about the level of knowledge were statistically analyzed using the correspondence analysis. Less than 40% of athletes had the knowledge about the proper and intended use of protein, creatine, amino acids, beta alanine and glutamine, while they had greater understanding about vitamins and minerals, sports drinks and caffeine. The athletes in developed countries had greater access and utilization of professional resources such as dieticians. Young athletes are still unfamiliar with WADA regulations (55.5%), and the misuse of sports supplements represents an ethical dilemma for some.

Conclusion

These findings indicate the necessity of a comprehensive education of all team members about sports supplements and careful supervision of the athletic development of young athletes.

Electronic supplementary material

The online version of this article (10.1186/s12970-019-0294-7) contains supplementary material, which is available to authorized users.

Metabolomics profiling of xenobiotics in elite athletes: relevance to supplement consumption

Background

Supplements are widely used among elite athletes to maintain health and improve performance. Despite multiple studies investigating use of dietary supplements by athletes, a comprehensive profiling of serum supplement metabolites in elite athletes is still lacking. This study aims to analyze the presence of various xenobiotics in serum samples from elite athletes of different sports, focusing on metabolites that potentially originate from nutritional supplements.

Methods

Profiling of xenobiotics in serum samples from 478 elite athletes from different sports (football, athletics, cycling, rugby, swimming, boxing and rowing) was performed using non-targeted metabolomics-based mass spectroscopy combined with ultrahigh-performance liquid chromatography. Multivariate analysis was performed using orthogonal partial least squares discriminant analysis. Differences in metabolic levels among different sport groups were identified by univariate linear models.

Results

Out of the 102 detected xenobiotics, 21 were significantly different among sport groups including metabolites that potentially prolong exercise tolerance (caffeic acid), carry a nootropic effect (2-pyrrolidinone), exert a potent anti-oxidant effect (eugenol, ferulic acid 4 sulfate, thioproline, retinol), or originate from drugs for different types of injuries (ectoine, quinate). Using Gaussian graphical modelling, a metabolic network that links various sport group-associated xenobiotics was constructed to further understand their metabolic pathways.

Conclusions

This pilot data provides evidence that athletes from different sports exhibit a distinct xenobiotic profile that may reflect their drug/supplement use, diet and exposure to various chemicals. Because of limitation in the study design, replication studies are warranted to confirm results in independent data sets, aiming ultimately for better assessment of dietary supplement use by athletes.

Athletes and Supplements: Prevalence and Perspectives

In elite sport, where opponents are evenly matched, small factors can determine the outcome of sporting contests. Not all athletes know the value of making wise nutrition choices, but anything that might give a competitive edge, including dietary supplements, can seem attractive. Between 40% and 100% of athletes typically use supplements, depending on the type of sport, level of competition, and the definition of supplements. However, unless the athlete has a nutrient deficiency, supplementation may not improve performance and may have a detrimental effect on both performance and health. Dietary supplements are classified as a subcategory of food, so manufacturers are not required to provide evidence of product safety and efficacy, nor obtain approval from regulatory bodies before marketing supplements. This creates the potential for health risks, and serious adverse effects have been reported from the use of some dietary supplements. Athletes who compete in sports under an anti-doping code must also realize that supplement use exposes them to a risk of ingesting banned substances or precursors of prohibited substances. Government systems of regulations do not include specific laboratory testing for banned substances according to the WADA list, so a separate regulatory framework to evaluate supplements for their risk of provoking a failed doping test is needed. In the high-performance culture typical of elite sport, athletes may use supplements regardless of possible risks. A discussion around medical, physiological, cultural, and ethical questions may be warranted to ensure that the athlete has the information needed to make an informed choice.

Dietary Supplement Intake and Associated Factors Among Gym Users in a University Community

Dietary supplement intake and associated factors among gym users in a university community in Sharjah, United Arab Emirates (UAE), were assessed using a structured, self-administered questionnaire in this cross-sectional study. Adults (N = 320) from five gyms in the University City of Sharjah participated in this cross-sectional study. The prevalence of dietary supplement intake was 43.8%. Statistically significant associations were found between the use of dietary supplements and sex (47.7% males, 28.1% females; p = .006), as well as weight lifting (88.6% taking supplements vs. 11.4% not taking supplements; p < .001), favoring male gym users. The reasons attributed to the use of dietary supplements varied between the sexes. Male exercisers used supplements to increase or maintain muscles mass, strength, and power and to boost exercise recovery. Females mainly used dietary supplements to increase energy, maintain their health, and prevent nutrition deficiency. Overall, protein supplements (whey proteins [48.6%] and protein powder [45.7%]) were among the most-consumed dietary supplements, followed by multivitamins (38.6%), branched-chain amino acids (36.4%), caffeine (35.0%), and creatine (29.3%). A widespread use of Internet-driven, self-prescribed dietary supplement intake was reported among gym users (60.7%). Only 12.8% of dietary supplement users sought information from dietitians. Practical implications suggest that gym instructors and coaches should be sufficiently trained to be able to provide accurate and scientifically sound information on dietary supplements to the exercisers in gyms in the university environment.

Use of dietary supplements among Brazilian athletes

ABSTRACT Objective: To investigate the prevalence and establish the profile of the consumption of dietary supplements among Brazilian athletes. Methods: A total of 182 athletes of both genders from 20 different sports participated in this study. The athletes answered a questionnaire containing sociodemographic and sports-related questions and were interviewed about the consumption of dietary supplements. Results: Forty seven percent of athletes reported having consumed at least one type of dietary supplement and 38% said they use more than three different types of supplements concurrently. Whey protein was the most commonly consumed supplement, and the most frequently mentioned reason for its consumption was performance improvement. The main source of information was coaches, and individual sport athletes were the greatest consumers and the most likely to seek dietary supplement. Conclusion: Approximately half of the participants used dietary supplements, which on most occasions were recommended by coaches. The consumption profile also revealed multiple supplementation practice and showed that nutrition education is essential for this specific population.

FATORES ASSOCIADOS AO USO DE SUPLEMENTOS ALIMENTARES ENTRE ATLETAS: REVISÃO SISTEMÁTICA

RESUMO A prevalência de consumo de suplementos alimentares entre atletas tem sido estudada exaustivamente. Contudo, não foi encontrado estudo que reúna e discuta, de forma sistematizada, os fatores que podem desencadear o consumo de suplementos entre atletas. O objetivo foi descrever a prevalência e as características do consumo e compreender quais fatores estão associados ao uso dos suplementos alimentares nessa população específica. Realizou-se uma pesquisa bibliográfica nas seguintes bases de dados: PubMed, Lilacs e Scielo. O Google Scholar foi consultado para identificação de material adicional. Foram incluídos estudos que investigaram a prevalência do uso de suplementos alimentares entre atletas, seus fatores associados, sem limite de idade e em ambos os sexos. De 374 estudos identificados, dezessete foram incluídos nesta revisão. Todos os estudos utilizaram delineamento transversal e o instrumento de coleta mais utilizado foi o questionário autoadministrado. A prevalência do uso de suplementos variou de 37,5% a 98%. Os atletas têm consumido mais vitaminas buscando informações com seus técnicos, visando melhorar o estado geral de saúde. "Prática de esporte individual" e "alto volume de treinamento" foram identificados como fatores associados ao uso de suplementos alimentares. A partir dos dados revisados, verificou-se um amplo intervalo de variação na utilização de suplementos pelos atletas. Os atletas têm consumido mais vitaminas e procuraram informações sobre o consumo com seus treinadores, com o objetivo de melhorar a sua saúde. Esta revisão também destaca a necessidade de uma investigação de alta qualidade sobre os correlatos de consumo de suplemento em atletas, uma vez que os dados foram discrepantes para muitos fatores relatados pelos estudos.

Patterns of Nutrition and Dietary Supplements Use in Young Egyptian Athletes: A Community-Based Cross-Sectional Survey

The aim of this study was to investigate the pattern of basic and sport nutrition as well as perspectives of young Egyptian athletes. Structured interview survey measuring knowledge, attitudes, beliefs and behaviors about basic and sport nutrition was administered to adolescent athletes recruited from 4 sport clubs and 2 fitness centers in Greater Cairo governorate. A total of 358 participants aged 13–18 years completed questionnaires. Basic nutrition knowledge was reasonable in almost all domains except fast food. Fixed breakfast (78.5%), home meals (lunch, 70.7%), and healthy snacks (55.8%) were the most positive features of the basic dietary pattern. More than 70% perceived themselves as knowledgeable about sport nutrition. The prevalence rate of sport supplement intake was (48.9%, n = 175), predominantly sport drinks (66.9%) and creatine (54.3%). Coaches were the primary source of sport nutrition information. Forty-four percent of participants (n = 77/175) reported supplement consumption during competition seasons only. Better physical appearance and enhancement of athletic performance were the major motivations for supplement intake. These findings indicate the necessity of a comprehensive nutrition education program targeting not only athletes and parents, but also coaching staff, health trainers and all sport team officials.

Prevalence, knowledge and attitudes relating to β-alanine use among professional footballers

OBJECTIVES

To investigate β-alanine supplementation use and level of knowledge amongst professional footballers.

DESIGN

Cross-sectional survey of Australian professional football players.

METHODS

Questionnaires assessing β-alanine supplementation behaviours, level of knowledge and sources of information were completed by professional rugby union (RU) (n=87), rugby league (RL) (n=180) and Australian Rules Football (ARF) (n=303) players.

RESULTS

Approximately 61% of athletes reported β-alanine use, however use by ARF football players (44%) was lower than that of RU (80%) and RL players (80%). The majority of respondents were not using β-alanine in accordance with recommendations. Only 35% of the participants were able to correctly identify the potential benefits of β-alanine supplementation. The main information sources that influenced players' decision to use β-alanine were strength and conditioning coach (71%) and dietitian (52%). Forty-eight per cent of athletes never read labels prior to supplementing and only 11% completed their own research on β-alanine. Compared to RL and ARF players, RU players had both a greater knowledge of β-alanine supplementation and better supplementation practices.

CONCLUSIONS

Despite over half the surveyed professional footballers using β-alanine, the majority of athletes used β-alanine in a manner inconsistent with recommendations. A better understanding of the environment and culture within professional football codes is required before supplement use becomes consistent with evidence based supplement recommendations.

Self-Reported Use and Reasons among the General Population for Using Sports Nutrition Products and Dietary Supplements

The purpose of the present study was to determine the prevalence of dietary supplements (DS's) and sport nutrition product (SNPs) among the general population, to identify differences for gender, age, and exercise frequency, and to determine the main reasons for use. The study was designed as a web-based questionnaire in a representative sample (n = 1544) of the Dutch population. Sixty-two percent (n = 957) of the respondents reported having used DS's, SNPs, or both in the last twelve months. Women and older people reported the highest DS use. The highest use of SNPs was reported by regular exercising men and younger people with improving sporting performance as their main objective. Most frequently reported DS's were multivitamins (28%) and vitamin C (19%)-for SNPs, energy drinks (22%) and isotonic drinks (19%). Health considerations were the most important motivation (DS's 90% and SNPs 52%), but also performance was substantially reported (DS's 14% and SNPs 35%). A substantial group of sedentary respondents also reported the use of SNPs. This study confirms that DS's, SNPs, or both are widely used among the general population. Both health as performance are important reasons for use. It can be questioned whether the use of SNPs fits all respondents' physical activity needs.

Use of nutritional supplements by Danish elite athletes and fitness customers

The nutritional supplement (NS) industry is one of the fastest growing in the world, and NS use in Denmark is among the highest in Europe. However, the exact use in elite athletes and fitness customers targeted for doping control is unknown. Information from 634 doping control forms obtained in 2014 was evaluated (elite athletes: n = 361; fitness customers: n = 273). The majority of female (92.6%) and male (85.0%) elite athletes and female (100.0%) and male (94.0%) fitness customers declared using one or more NS. The use of non-ergogenic NS was more prevalent in women than in men and in younger (15-34 years) compared with older (35-49 years) subjects, but it was less prevalent in intermittent compared with endurance and power/strength sports. Additionally, fitness customers who tested positive for doping also reported using more NS than subjects testing negative, indicating an association between NS and doping abuse. The present results demonstrate a very high prevalence of NS usage in both elite athletes and fitness customers. This highlights the importance of a strong national regulation of NS to avoid contamination of NS with doping substances.

Effect of taking dietary supplement on hematological and biochemical parameters in male bodybuilders an equation model

Background:

The improved physical action following administration of supplements to bodybuilders was supported by changes in laboratory parameters. Despite the fact that these supplements are sometimes associated both advantage and side effects, this study were conducted for the purpose of evaluating the possible effects of some commonly used supplements in bodybuilders on the hematological and biochemical parameters.

Materials and Methods:

In this study, we included 40 male bodybuilders as cases and 40 controls in the age group of 20-40 years. They used different kinds of supplements for 1 year. In general, all the supplements used were classified into two groups: hormonal and non-hormonal. Laboratory tests were requested for evaluation of hematological and biochemical parameters.

Results:

In an equation model, we found that weight (P = 0.024), duration of bodybuilding (P < 0.001), and duration of hormone supplement consumption (P < 0.001) were loaded significantly on the latent variables, demographic and dietary supplement, respectively. The relationship between dietary supplement and biochemical and hematological parameters was significant (P = 0.01) and some of these parameters including creatinine (P = 0.023), blood aspartate aminotransferase (AST) (P < 0.001), alanine aminotransferase (ALT) (P < 0.001), and red blood cell distribution (RDW) (P = 0.046) had a significant role than others. In a multivariate regression model, we found that WBC (P < 0.001), platelets (P < 0.001), blood urea nitrogen (BUN; P < 0.001), creatinine (P < 0.001), AST (P = 0.005), and ALT (P = 0.001) were higher in athletes than in controls.

Conclusions:

It is strongly advised that there should be some concerns about possible supplement-induced changes in the laboratory exams for bodybuilders. The available supplements are unchecked and not approved by the US Food and Drug Administration (FDA). More studies should be designed for a better and precise administration of each supplement in athletes.

Prevalence of Dietary Supplement Use by Athletes: Systematic Review and Meta-Analysis

BACKGROUND

Dietary supplements (DSs) are commercially available products consumed as an addition to the usual diet and are frequently ingested by athletes.

OBJECTIVE

Our objective was to examine the prevalence of DS use by athletes.

DATA SOURCES

PubMed, Ovid MEDLINE, OVID Healthstar, and Cumulative Index to Nursing and Allied Health were searched for original research articles published up to August 2014. Search terms included specific sports, specific DSs, and other terms.

STUDY SELECTION

Studies were selected if they were written in English, involved athletes, and provided a quantitative assessment of the proportion of athletes using specific DSs. Percent of athletes using specific DSs.

SYNTHESIS OF DATA

Methodological quality of studies was assessed by three reviewers using an 8-point scale that included evaluations for sampling methods, sampling frame, sample size, measurement tools, bias, response rate, statistical presentation, and description of the participant sample. Where there were at least two investigations, meta-analysis was performed to obtain summary (pooled) prevalence estimates (SPEs) on (1) DS use prevalence by sport and sex, (2) DS use prevalence by elite versus non-elite athletic status, and (3) specific DS prevalence for all athletic groups combined. Meta-analyses included evaluations of homogeneity and publication bias.

RESULTS

A total of 159 unique studies met the review criteria. Methodological quality was generally low with an average ± standard deviation of 43 ± 16% of available rating points. There was low homogeneity for SPEs when compiled by sport, athletic status, and/or specific DSs. Contributing to the lack of homogeneity were differences in studies' objectives and types of assessments used (e.g., dietary surveys, interviews, questionnaires). Despite these limitations, the data generally indicated that elite athletes used DSs much more than their non-elite counterparts. For most DSs, use prevalence was similar for men and women except that a larger proportion of women used iron while a larger proportion of men used vitamin E, protein, and creatine. No consistent change in use over time was observed because even the earliest investigations showed relatively high use prevalence.

CONCLUSION

It was difficult to generalize regarding DS use by athletes because of the lack of homogeneity among studies. Nonetheless, the data suggested that elite athletes used dietary supplements far more than their non-elite counterparts; use was similar for men and women with a few exceptions; use appeared to change little over time; and a larger proportion of athletes used DSs compared with the general US population. Improvements in study methodology should be considered in future studies especially (1) defining DSs for participants; (2) querying for very specific DSs; (3) using a variety of reporting timeframes (e.g., daily, 2-6 times/week, 1 time/week and <1 time/week); (4) reporting the sampling frame, number of individuals solicited, and number responding; (5) reporting characteristics of volunteers (and non-volunteers, if available); and (6) using similar methods on several occasions to examine possible temporal trends among athletes.

The estimation of mineral contents in oriental supplements consumed by elite athletes

The purpose of this study is twofold: to examine macro (calcium, magnesium, and phosphorus) and trace mineral (iron) concentration in oriental supplements (OS), and to define OS prevalence in elite athletes. Participants of this study were 928 varsity athletes (male: 680, female: 248) with 23 sports types. Recent 3-month dietary supplements (DS) and OS practice was surveyed during training period, and mineral concentration in 72 randomly collected OS samples were analyzed. DS use was 41% and OS use was 20% in university elite athletes. Most common OS use informants were parents (74%). OS intake reason was for health maintenance (37%), energy supplement (25%), and recovery improvement (15%). Moreover, health maintenance was higher in females (47%) than males (32%) while energy supplement was higher in males (28%) than females (18%) (χ(2)(8) = 17.676, p = 0.024). Beliefs in OS efficacy and importance were significantly higher in female athletes compared to male athletes (p < 0.05). Macro mineral concentration in OS was calcium (7.54 ppm), magnesium (4.63 ppm), and phosphorus (205.34 ppb) and trace mineral concentration in OS was iron (8.10 ppb), which was a small amount. An association between OS intake reason and mineral concentration in calcium, phosphorus, and iron was found, but no association between OS intake and magnesium. In conclusion, an association between OS intake reason and mineral concentration differed by the ingredients. Minerals in OS were very small amount, which would be improved for mineral balance in elite athletes.

Protein supplementation and dietary behaviours of resistance trained men and women attending commercial gyms: a comparative study between the city centre and the suburbs of Palermo, Italy

Background

It is anecdotally recognized that commercial gym users assume supplements in order to improve performance or health. However, dietary behaviours of people and athletes attending commercial gyms have been poorly studied. The exact amount and frequency of dietary supplements consumption are still needed to be investigated. The main purpose of this study is to understand the quantity and quality of food intake, as well as dietary supplementation in people attending commercial gyms. Secondly to compare the city centre and the suburbs of Palermo, Italy.

Methods

A face-to-face questionnaire was administered to 561 subjects, 207 from the city centre (CC) and 354 from the suburbs (SB) of Palermo, Italy. Frequency of protein supplements use and association with dietary behaviours were investigated. Subsequently, the frequency distribution was used for demographic assessment.

Results

Frequency of protein consumption was similar in both groups (30% for CC and 28.8% for SB). Males show greater consumption percentages than females (30.5% in males and 6.9% in females). Milk and chicken are the most frequently consumed foods. Data show that non-supplement users (NSU) consume significantly more snacks and bakery products than supplement users (SU) (P < 0.001). While, SU consume significantly higher quantities of vegetables, nuts, fresh fish, eggs and canned tuna (P < 0.001). SU consume less low protein food and higher protein foods than NSU. No differences were found between CC and SB.

Conclusions

Protein consumption among commercial gym users is 30% for the CC and 28.8% for the SB. Significant differences were found between CC and SB females, underlining an interesting discrepancy, indicating to dietary supplement industries regarding regional implications. Subjects that use protein supplements also consume larger quantities of high protein food compared to NSU. NSU also eat higher proportions of unhealthy food compared to SU.

Verification of efficacy as an ergogenic aid and safety in doping of sibjeondaebo-tang

[Purpose]

[Methods]

[Results]

[Conclusion]

Dietary supplement and drug use and doping knowledge and attitudes in Italian young elite cyclists

OBJECTIVE

To explore use and attitudes toward drugs and dietary supplements (DS) and knowledge concerning doping in cycling.

DESIGN

Retrospective cross-sectional study.

SETTING

Professional cycling.

PARTICIPANTS

Elite under-23 male cyclists.

INTERVENTION

Anonymous semistructured questionnaire administered during race periods.

MAIN OUTCOME MEASURES

Use and attitudes toward DS and drugs, and doping knowledge.

RESULTS

Forty cyclists aged 19 to 23 years and practicing for 14 to 30 h/wk were interviewed. Previous use (last 3 months) of drugs or DS occurred in 33 of 40 (82.5%) and 39 of 40 (97.5%) cyclists, respectively. Almost all the subjects named at least 1 doping agent (range, 1-10). Within a fixed list of 18 substances (among which only 14 were doping agents), participants recognized 3 to 18 of them as doping agents. They recognized tramadol and sildenafil as doping agents, which are not doping agents, and failed to recognize probenecid and albumin, which actually are. Doping knowledge correlated with drug use (r2 = 0.1614; P = 0.01). Participants deemed doping prevalence high among cyclists in general but not in their own team (P < 0.0001).

CONCLUSIONS

Use of prescription drugs and DS was a common occurrence. Doping knowledge was poor and biased, and its relationship with drug use deserves consideration. Educational interventions are needed to improve knowledge and awareness about prescription drugs and DS use, as well as about doping.

Effects of creatine monohydrate supplementation on simulated soccer performance

PURPOSE

To determine the effects of acute short-term creatine (Cr) supplementation on physical performance during a 90-min soccer-specific performance test.

METHODS

A double-blind, placebo-controlled experimental design was adopted during which 16 male amateur soccer players were required to consume 20 g/d Cr for 7 d or a placebo. A Ball-Sport Endurance and Speed Test (BEAST) comprising measures of aerobic (circuit time), speed (12- and 20-m sprint), and explosive-power (vertical jump) abilities performed over 90 min was performed presupplementation and postsupplementation.

RESULTS

Performance measures during the BEAST deteriorated during the second half relative to the first for both Cr (1.2-2.3%) and placebo (1.0-2.2%) groups, indicating a fatigue effect associated with the BEAST. However, no significant differences existed between groups, suggesting that Cr had no performance-enhancing effect or ability to offset fatigue. When effect sizes were considered, some measures (12-m sprint, -0.53 ± 0.69; 20-m sprint, -0.39 ± 0.59) showed a negative tendency, indicating chances of harm were greater than chances of benefit.

CONCLUSIONS

Acute short-term Cr supplementation has no beneficial effect on physical measures obtained during a 90-min soccer-simulation test, thus bringing into question its potential as an effective ergogenic aid for soccer players.

Randomized response estimates for the 12-month prevalence of cognitive-enhancing drug use in university students

STUDY OBJECTIVE

To estimate the 12-month prevalence of cognitive-enhancing drug use.

DESIGN

Paper-and-pencil questionnaire that used the randomized response technique.

SETTING

University in Mainz, Germany.

PARTICIPANTS

A total of 2569 university students who completed the questionnaire.

MEASUREMENTS AND MAIN RESULTS

An anonymous, specialized questionnaire that used the randomized response technique was distributed to students at the beginning of classes and was collected afterward. From the responses, we calculated the prevalence of students taking drugs only to improve their cognitive performance and not to treat underlying mental disorders such as attention-deficit-hyperactivity disorder, depression, and sleep disorders. The estimated 12-month prevalence of using cognitive-enhancing drugs was 20%. Prevalence varied by sex (male 23.7%, female 17.0%), field of study (highest in students studying sports-related fields, 25.4%), and semester (first semester 24.3%, beyond first semester 16.7%). To our knowledge, this is the first time that the randomized response technique has been used to survey students about cognitive-enhancing drug use.

CONCLUSION

Using the randomized response technique, our questionnaire provided data that showed a high 12-month prevalence of cognitive-enhancing drug use in German university students. Our study suggests that other direct survey techniques have underestimated the use of these drugs. Drug prevention programs need to be established at universities to address this issue.

Supplements and Foods with Potential Reduction of Blood Pressure in Prehypertensive and Hypertensive Subjects: A Systematic Review

Although the dietary approaches for stop hypertension (DASH) is well established and effective in reduction of blood pressure, in recent years, new scientific studies have indicated that specific food, nutrients isolated from foods, and even commercial food supplements are not covered by DASH. In this research, these nutrients were evaluated through a review using the databases of PubMed with the terms “dietary supplements and blood pressure” without a limit of date. Vitamins (C, D, and E) and minerals (potassium and copper) promote the greatest reductions in BP, around 7 to 14 mmHg for systolic blood pressure (SBP) and 4 to 5 mmHg for diastolic blood pressure (PAD). Antioxidants reduce SBP and DBP in 3 to 27 mmHg and 3 to 4 mmHg, respectively. Among the amino acids, only L-arginine was effective in promoting reduction of 20 and 15 mmHg for SBP and DBP, respectively. In food, the grape juice promoted the highest reductions in SBP and DBP, around 8 mmHg and 6 mmHg, respectively. Finally, for commercial supplements, the fermented milk product GAIOR, the grain salba, and fish oil promoted reductions of about 4,4; 6; and 5 mmHg and 3,4; 3; and 1 mmHg for SBP and DBP, respectively. Therefore, new nutrients, foods, and supplements can enrich the recommendations of the DASH.

Effect of dietary antioxidants, training, and performance correlates on antioxidant status in competitive rowers

The beneficial effects of exercise and a healthy diet are well documented in the general population but poorly understood in elite athletes. Previous research in subelite athletes suggests that regular training and an antioxidant-rich diet enhance antioxidant defenses but not performance.

PURPOSE

To investigate whether habitual diet and/or exercise (training status or performance) affect antioxidant status in elite athletes.

METHODS

Antioxidant blood biomarkers were assessed before and after a 30-min ergometer time trial in 28 male and 34 female rowers. The antioxidant blood biomarkers included ascorbic acid, uric acid, total antioxidant capacity (TAC), erythrocyte- superoxide dismutase, glutathione peroxidase (GPx), and catalase. Rowers completed a 7-d food diary and an antioxidant-intake questionnaire. Effects of diet, training, and performance on resting biomarkers were assessed with Pearson correlations, and their effect on exercise-induced changes in blood biomarkers was assessed by a method of standardization.

RESULTS

With the exception of GPx, there were small to moderate increases with exercise for all markers. Blood resting TAC had a small correlation with total antioxidant intake (correlation .29; 90% confidence limits, ±.27), and the exercise-induced change in TAC had a trivial to small association with dietary antioxidant intake from vitamin C (standardized effect .19; ±.22), vegetables (.20; ±.23), and vitamin A (.25; ±.27). Most other dietary intakes had trivial associations with antioxidant biomarkers. Years of training had a small inverse correlation with TAC (-.32; ±.19) and a small association with the exercise-induced change in TAC (.27; ±.24).

CONCLUSION

Training status correlates more strongly with antioxidant status than diet does.

Dietary supplementation and doping-related factors in high-level sailing

Background

Although dietary supplements (DSs) in sports are considered a natural need resulting from athletes’ increased physical demands, and although they are often consumed by athletes, data on DS usage in Olympic sailing are scarce. The aim of this study was to study the use of and attitudes towards DSs and doping problems in high-level competitive sailing.

Methods

The sample consisted of 44 high-level sailing athletes (5 of whom were female; total mean age 24.13 ± 6.67 years) and 34 coaches (1 of whom was female; total mean age 37.01 ± 11.70). An extensive, self-administered questionnaire of substance use was used, and the subjects were asked about sociodemographic data, sport-related factors, DS-related factors (i.e., usage of and knowledge about DSs, sources of information), and doping-related factors. The Kruskal-Wallis ANOVA was used to determine the differences in group characteristics, and Spearman’s rank order correlation and a logistic regression analysis were used to define the relationships between the studied variables.

Results

DS usage is relatively high. More than 77% of athletes consume DSs, and 38% do so on a regular basis (daily). The athletes place a high degree of trust in their coaches and/or physicians regarding DSs and doping. The most important reason for not consuming DSs is the opinion that DSs are useless and a lack of knowledge about DSs. The likelihood of doping is low, and one-third of the subjects believe that doping occurs in sailing (no significant differences between athletes and coaches). The logistic regression found crew number (i.e., single vs. double crew) to be the single significant predictor of DS usage, with a higher probability of DS consumption among single crews.

Conclusion

Because of the high consumption of DSs future investigations should focus on real nutritional needs in sailing sport. Also, since athletes reported that their coaches are the primary source of information about nutrition and DSs, further studies are necessary to determine the knowledge about nutrition, DSs and doping problems among athletes and their support teams (i.e., coaches, physicians, and strength and conditioning specialists).

Nutritional supplements: prevalence of use and contamination with doping agents

Based upon recent sales numbers, nutritional supplements play a key role in the lifestyle of a substantial proportion of the population. As well as products such as vitamins or minerals, several precursors of anabolic steroids are marketed as nutritional supplements. Another group of commercially available supplements are products for weight loss based upon herbal formulations originating from Ephedra species. Apart from supplements indicating the presence of these active compounds, numerous non-hormonal nutritional supplements were found that were contaminated with non-labelled anabolic steroids. Stimulating agents other than naturally occurring analogues of ephedrine were detected. A major group using dietary supplements are sportsmen, ranging from amateur level to elite athletes. Besides the possible health risks associated with the use of dietary supplements, athletes should take care not to violate the rules of the World Anti-Doping Agency because athletes remain responsible for substances detected in their biofluids, irrespective of their origin. Several analytical methods have been developed to determine the presence of doping agents as contaminants. The present review attempts to address the issues concerning the use of nutritional supplements and the detection of doping agents as contaminants in dietary supplements.

Toxic hepatitis in a group of 20 male body-builders taking dietary supplements

Dietary supplements have been used for decades for enhancing muscle growth. The harm caused by some of these products is well documented. We investigated and reported toxic hepatitis in 20 male athletes following self-prescribing of a number of dietary supplements which are lesser known. The patients' ages ranged from 24 to 32 with a mean of 28 years. They had taken three kinds of supplements for 1 year including testosterone optimizer agent T Bomb II, a creatine supplement Phosphagen and an amino acid based supplement Cell-Tech. Based on the history, clinical examination, and laboratory findings the cases were diagnosed as toxic hepatitis. After discontinuation of taking the supplements, clinical recovery and improvement of liver function tests were achieved within 30 days. Causality assessment with the CIOMS (Council for International Organization Medical Sciences) scale showed a "possible" grade of causality (+5 points) for these supplements. It can be concluded that these newer anabolic supplements may induce toxic hepatitis. Since the health risks of them may be severe, the use of these kinds of dietary supplements should be discouraged.

Intake of Nutritional Supplements among People Exercising in Gyms in Beirut City

The use of nutritional supplements among exercisers in gyms has been never investigated in the Middle East. The aim of the current study was to assess the prevalence intake of nutritional supplements and the potential influencing factors among people exercising in gyms in Beirut city. In this cross-sectional study, 512 exercisers, aged between 20 and 50 years, were randomly selected from gyms. The intake of nutritional supplements was reported among 36.3% (95% confidence interval 32.2–40.5) of participants, with a weak presence of medical supervision. Patterns of supplement use differed by gender and age. Men and younger exercisers were found to focus on supplements associated with performance enhancement and muscle building, while women and older exercisers were more concerned with health-promoting products such as vitamins, minerals, and herbal supplements. An appropriate dissemination of accurate and scientifically sound information regarding the benefits and side effects of nutritional supplements is highly recommended in the sports environment in Beirut city.

Nutritional supplement use among Slovenian adolescents

OBJECTIVE

Little is known about the prevalence of nutritional supplement use in European adolescents. We conducted the present study to analyse the prevalence of nutritional supplement use and factors associated with this use among Slovenian adolescents.

DESIGN

The nutritional supplementation practices of 818 adolescents were studied using an anonymous questionnaire. Information was sought on the type of supplements used, frequency of use and sources of information.

SETTING

The region of north-west Slovenia.

SUBJECTS

Schoolchildren from twenty primary schools and twelve secondary schools.

RESULTS

Some 19·3% of all adolescents reported using at least one nutritional supplement and the prevalence of use was significantly higher in adolescents who were members of sports clubs. Multivitamins were the most common nutritional supplement. Older adolescents were significantly more likely to be supplementing with iron, protein and minerals. Less than 16% of supplement users in our study sought information from health-care professionals. Nearly 62% obtained information from parents and coaches, and many adolescents appear to decide on nutritional supplementation themselves, without advice. Older adolescents were significantly more likely to combine supplements than younger adolescents.

CONCLUSIONS

One-fifth of Slovenian adolescents use nutritional supplements. There are clear differences in supplement use between younger (age 12 years) and older (age 17 years) adolescents. Multiple use of supplements, coupled with self-managed supplementation in older adolescents, is concerning. Hence, there is an urgent need to provide accurate information regarding nutritional supplements, which will help adolescents, their parents and coaches to make informed choices about their use.

Anti-doping education and dietary supplementation practice in Korean elite university athletes

This study was conducted to investigate relationships and gender differences in dietary supplement (DS) and oriental supplement (OS) prevalence as well as anti-doping awareness during training and the game period. Korea National Sport University athletes (343 male and 136 female) participated in this study and completed DS and OS practice and anti-doping awareness questionnaires. Forty-six percent of athletes used DS during the training period, and there was significantly higher DS use in females (53%) compared to males (43%) (P < 0.05). Twenty-eight percent of athletes used OS, and there was significantly higher OS use in females (35%) than males (26%) (P < 0.05) during the training period. The primary reason of DS use was to supply energy both in males (36%) and females (28%). The main reason for male athletes' OS use was to supply energy (41%). Meanwhile, the reasons for female athletes' OS use were to supply energy (23%), to maintain health (19%), and to improve recovery ability (20%), which showed a significant gender difference (P < 0.05). Athletes rated their perceived degree of satisfaction, perceived importance, and beliefs in efficacy of DS and OS use all over 50% during the training period, and no gender differences were detected. In a comparison between athletes educated about anti-doping (at least more than one time) and non-received athletes, DS and OS use during the training period was 2.30 (1.47-3.60) and 1.71 (1.03-2.82), respectively. DS and OS use immediately before the game period was 2.38 (1.50-3.80) and 3.99 (1.20-13.28), respectively. Elite athletes' anti-doping education was highly related to increased DS use during the training period and immediately before the game. Although elite athletes use various DS and OS during the training period and before the game period, doping education for elite athletes is related with DS and OS use during the training period and before the game.

The Physiological Effects of Creatine Supplementation on Hydration: A Review

In 1992, Harris and colleagues demonstrated that oral creatine supplementation can enhance muscle creatine stores. Since then, creatine has become an important and popular ergogenic aid for improving athletic performance with reports of up to 74% of athletes supplementing with creatine. Although many recent studies have addressed the safety concerns of creatine supplementation on hydration status in hot and humid environments, anecdotal reports still exist linking creatine usage to heat-related problems. These concerns are based on the premise that creatine is an osmotically active substance resulting in an alteration in fluid balance by increasing intracellular fluid volume and preventing fluid from entering the extracellular environment to aid in thermoregulation. However, a number studies have demonstrated that when recommended amounts of creatine are consumed, creatine does not appear to increase the risk of heat-related problems during exercise and may actually have a positive influence on core temperature and heart rate responses.

Effects of various sodium bicarbonate loading protocols on the time-dependent extracellular buffering profile

Although much research has investigated the types of exercise that are enhanced with sodium bicarbonate (NaHCO3) ingestion, to date, there has been limited research on the dosage and timing of ingestion that optimizes the associated ergogenic effects. This study investigated the effects of various NaHCO3 loading protocols on the time-dependent blood-buffering profile. Eight male volunteers (age, 22.4 +/- 5.7 yr; height, 179.8 +/- 9.6 cm, body mass, 76.3 +/- 14.1 kg) completed Part A, measures of alkalosis throughout 120 minutes after ingestion of various single NaHCO3 dosages (0.3 gxkg-1, 0.2 gxkg-1, 0.1 gxkg-1, and placebo); and Part B, similar profiles after alternative NaHCO3 loading protocols (single morning dosage [SMD], single evening dosage [SED], and dosages ingested on 3 consecutive evenings [CED]). Results from Part A are as follows. Blood buffering in the 0.1 gxkg-1 condition was significantly lower than the 0.2 g.kg-1 and 0.3 gxkg-1 conditions (p < 0.002), but there was no significant differences between the 0.2 gxkg -1and 0.3 g.kg-1 conditions (p = 0.34). Although the blood buffering was relatively constant in the 0.1 and 0.2 conditions, it was significantly higher at 60 minutes than at 100 minutes and 120 minutes in the 0.3 gxkg-1 condition (p < 0.05). Results from Part B are as follows. Blood buffering for SMD was significantly higher than for SED and CED (p < 0.05). Blood buffering in the SMD condition was significantly lower at 17:00 hours than at 11:00 hours (p = 0.007). The single 0.2 and 0.3 gxkg-1 NaHCO3 dosages appeared to be the most effective for increasing blood-buffering capacity. The 0.2 gxkg-1 dosage is best ingested 40 to 50 minutes before exercise and the 0.3 gxkg-1 dosage 60 minutes before exercise.