The continuing story of nutritional supplements and doping infractions

High School Athletes' Use and Knowledge of (Safe) Nutritional Supplement Use: An Exploratory Study

The use of nutritional supplements can lead to doping risk and no data exist on high school athletes' use of certified third-party tested supplements. A cross-sectional cohort design was developed using an anonymous survey. Descriptive data for supplement use, use of third-party tested supplements, and knowledge in high school athletes were reported. A total of 225 high school athletes, ranging from 14-19 years of age, from a private high school in the western US, were included in the analysis of the results. A total of 94% (n=211) of athletes reported nutritional supplement use within the past year with an average of six (interquartile range: 3-9) individual supplements, ranging from 0-20 supplements per person. Most frequently reported were sports drinks (72%), vitamins (65%), sports bars (60%), protein powder (58%), caffeine (37%, as part of normal beverages, or 13% as a supplement), followed by creatine (23%). A total of 24% claimed to know for sure that all their supplements were third-party tested. In addition, the recognition of third-party testing organization icons was low (46% in supplement users vs. 14% in nonusers). Athletes also scored low in reporting how to find (22%) and how to order (25%) third-party tested supplements. In conclusion, almost all athletes in this study reported the use of multiple nutritional supplements annually. Only one-fourth of the athletes reported consistently using third-party tested supplements. Knowledge of where and how tested supplements could be purchased was limited in this high school athlete population.

Dietary Supplements as a Major Cause of Anti-doping Rule Violations

Dietary supplements encompass a large heterogenic group of products with a wide range of ingredients and declared effects used by athletes for a multitude of reasons. The high prevalence of use across all sports and level of competition, combined with the well-documented risks of such products containing prohibited substances have led to several doping cases globally. Despite being a considerable concern and persistent focus of sport organizations and anti-doping agencies, the magnitude of anti-doping rule violations associated with supplement use is not well-known. This study examines 18-years of doping controls of a national anti-doping program to determine the relationship between the presence of prohibited substances in athlete's doping samples and the use of dietary supplements. In 26% (n = 49) of all the analytical anti-doping rule violation cases in the period 2003–2020 (n = 192), the athlete claimed that a dietary supplement was the source of the prohibited substance causing an adverse analytical finding. Evidence supporting this claim was found in about half of these cases (n = 27, i.e., 14% of all analytical ADRV's). Stimulants were the most prevalent substance group linked to supplements (n = 24), of which methylhexanamine was associated with 16 cases. High risk products were predominantly multi-ingredient pre-workout supplements (n = 20) and fat-burning products (n = 4). Anti-doping organizations should develop strategies on how to assist athletes to assess the need, assess the risk and assess the consequences of using various dietary supplements.

Suplementos alimentares: uma fonte de doping não intencional?

Resumo O excessivo consumo de suplementos alimentares, aliado a uma legislação inespecífica e a um controle de qualidade ineficiente, faz com que a saúde dos consumidores seja colocada em risco devido à possível existência de contaminantes, em especial pró-hormônios, esteroides anabolizantes e estimulantes. Estes compostos podem proporcionar um aumento do desempenho esportivo e acarretar uma série de efeitos adversos, sendo assim proibidos pela Agência Mundial Antidopagem. A contaminação de suplementos pode ocorrer de maneira deliberada ou através de más práticas de produção, em que são encontrados traços dessas substâncias. Todavia, ambos os casos exigem atenção, já que uma contaminação de apenas 0,00005% em massa pode levar ao doping. Neste sentido, estima-se que de 6,4% a 8,8% dos casos estejam relacionados ao consumo de suplementos contaminados. Perante estes fatos, os objetivos principais do trabalho foram: fazer uma revisão da literatura tanto em trabalhos nacionais quanto internacionais, no que concerne à contaminação de suplementos alimentares e sua relação com a dopagem não intencional, bem como orientar os consumidores a escolherem produtos mais seguros. Neste sentido, foi possível observar que os suplementos nacionais são, geralmente, mais seguros quanto à presença de substâncias proibidas, principalmente em relação à contaminação por agentes anabolizantes. Contudo, ainda é preciso um melhor controle de qualidade perante a contaminação/adulteração por estimulantes.

Dutch Olympic and Non-Olympic Athletes Differ in Knowledge of and Attitudes Toward Third-party Supplement Testing

Knowledge of third-party testing is important for elite athletes using nutritional supplements to reduce the chances of a positive doping incident. Therefore, we compared the self-reported knowledge and attitudes of N = 601 Dutch Olympic status and non-Olympic status athletes toward an independent Dutch third-party tested system (NZVT) for purchasing nutritional supplements (NSs). Most of the athletes believed that contaminated NSs could lead to a positive doping test (68.0%), and found it unacceptable to use a contaminated NS as a result of incomplete labeling (87.8%). More Olympic status athletes were familiar with the NZVT system (71.1%) than non-Olympic status athletes (24.5%, p < 0.001). Of the athletes knowing about NZVT, Olympic status athletes reported more frequently using the NZVT than non-Olympic athletes (81.7% vs. 50.0%, p < 0.001). Apart from status, more females were familiar with and used the NZVT system for purchasing NSs than males, p < 0.01. In conclusion, many athletes were not familiar with nor used the preferred third-party testing supplement system in the Netherlands when purchasing NSs. While doping warnings and regulations have been in place, considering the risk of unintentional doping use for over two decades, the knowledge of Olympic status and non-Olympic status high-level athletes could still be improved, as many are not reporting the use of third-party testing systems.

Third-Party Testing Nutritional Supplement Knowledge, Attitudes, and Use Among an NCAA I Collegiate Student-Athlete Population

Dietary supplements, sports foods, and ergogenic supplements are consumed to increase performance, recovery, and health, but risk contamination with illegal substances. Third-party testing programs may assist in regulating the purity and safety of supplements, yet athletes' attitudes and use of such programs are not widely reported. This study examined nutritional supplement knowledge, attitudes, and use, as well as the purchase of third-party tested supplements among university student-athletes (N = 138). Knowledge of nutritional supplements yielded a median and (IQR) score of 25% (17 to 42%). Sixteen percent of student-athletes said they were knowledgeable about supplements and their effects, p < 0.001. All athletes stated they used a dietary supplement or sports food at least once within the last 12 months, and 77% consumed at least one “claimed to be” ergogenic supplement. Sixty-six percent of student-athletes purchased nutritional supplements not provided by the athletic department. Females athletes were more likely to consume a combination of vitamins and single minerals, a larger variety of sports foods, exotic berries, herbs, maca root powder, ribose, ephedra, colostrum, and hydroxy-methyl-buterate (HMB) than males. Over 90% believed it was essential to know if a supplement was third-party tested. However, only 57% stated the supplements bought were third-party tested. No sex differences were found for nutritional supplement knowledge, attitudes, and use of third-party testing programs. Our results indicate a need to improve student-athletes' attitudes toward and knowledge of nutritional supplements, and the initiation of programs to assist in the choosing and consuming of third-party tested supplements.

Dietary Supplement Use among Non-athlete Students at a Canadian University: A Pilot-Survey

Despite the emerging evidence of adverse consequences and interaction with doping substances, dietary supplements (DS) are commonly used by many Canadians. The purpose of this study was to evaluate the patterns and determinants of current DS use among non-athlete students at a Canadian university using a cross-sectional approach. Of the 475 participants who completed the online survey, 43.4% declared using DS in the past six months. Participants who were male, aged ≥20 years old, and had a parent/guardian with a bachelor’s degree were significantly more likely to use DS. The types of DS used and the sources of information regarding DS were significantly influenced by age and gender. The most commonly used DS were vitamin and mineral and protein supplements. Most participants referred to healthcare professionals for information on DS, but many continued to depend on unreliable sources including family and friends. Of DS users, 10.1% reported experiencing adverse events from using DS. Findings from this study indicate that supplementation is very common among Canadian non-athlete students and highlight the urgent need for the development of educational programs surrounding DS use.

Dietary Supplement and Food Contaminations and Their Implications for Doping Controls

A narrative review with an overall aim of indicating the current state of knowledge and the relevance concerning food and supplement contamination and/or adulteration with doping agents and the respective implications for sports drug testing is presented. The identification of a doping agent (or its metabolite) in sports drug testing samples constitutes a violation of the anti-doping rules defined by the World Anti-Doping Agency. Reasons for such Adverse Analytical Findings (AAFs) include the intentional misuse of performance-enhancing/banned drugs; however, also the scenario of inadvertent administrations of doping agents was proven in the past, caused by, amongst others, the ingestion of contaminated dietary supplements, drugs, or food. Even though controversial positions concerning the effectiveness of dietary supplements in healthy subjects exist, they are frequently used by athletes, anticipating positive effects on health, recovery, and performance. However, most supplement users are unaware of the fact that the administration of such products can be associated with unforeseeable health risks and AAFs in sports. In particular anabolic androgenic steroids (AAS) and stimulants have been frequently found as undeclared ingredients of dietary supplements, either as a result of cross-contaminations due to substandard manufacturing practices and missing quality controls or an intentional admixture to increase the effectiveness of the preparations. Cross-contaminations were also found to affect therapeutic drug preparations. While the sensitivity of assays employed to test pharmaceuticals for impurities is in accordance with good manufacturing practice guidelines allowing to exclude any physiological effects, minute trace amounts of contaminating compounds can still result in positive doping tests. In addition, food was found to be a potential source of unintentional doping, the most prominent example being meat tainted with the anabolic agent clenbuterol. The athletes’ compliance with anti-doping rules is frequently tested by routine doping controls. Different measures including offers of topical information and education of the athletes as well as the maintenance of databases summarizing low- or high-risk supplements are important cornerstones in preventing unintentional anti-doping rule violations. Further, the collection of additional analytical data has been shown to allow for supporting result management processes.

A descriptive study on dietary pattern and biophysical profile among Saudi female dental students

Objective The current study aims to find out the dietary pattern among undergraduate dental students and evaluate its impact on their biophysical profile and academic achievement. Methods A convenient sample of 150 Saudi female dental students was selected as study participants, and a close-ended questionnaire divided into two parts was distributed among them.The questionnaire included questions on their eating habits, body mass index (BMI), waist-hip ratio (WHR), and blood pressure. The collected data was statistically analyzed using SPSS version 19, and the chi-square test, correlation analysis, and descriptive statistics were performed. Results It was observed that a majority (40%) of the study participants replaces their meals with snacks, and 26% did not take regular meals.The results reveal a significant association between blood pressure, BMI, and WHR among University female students. No significant association has been found between grade-point-average (GPA) and dietary pattern. Conclusions The study concluded that the majority of university female students consumed unhealthy diets such as snacks. Fruit intake was lower than the recommended amount by World Health Organisation (WHO). Conducting appropriate nutrition related-public health programs would be beneficial in raising awareness regarding different aspects of dietary habits.

An investigation on the metabolic pathways of synthetic isoflavones by gas chromatography coupled to high accuracy mass spectrometry

RATIONALE

Isoflavones are a group of flavonoids that may be of interest in sport doping because they can be used by athletes in the recovery periods after the administration of anabolic steroids, with the aim of increasing the natural production of luteinizing hormone (LH) and, consequently, the biosynthesis of endogenous androgens.

METHODS

The in vivo metabolism of methoxyisoflavone (5-methyl-7-methoxyisoflavone) and ipriflavone (7-isopropoxyisoflavone), respectively present in a dietary supplement and in a pharmaceutical preparation, was investigated. The study was carried out by the analysis of urinary samples collected from male Caucasian subjects before, during and after the oral administration of methoxyisoflavone or ipriflavone. After enzymatic hydrolysis and liquid-liquid extraction, all urinary samples were analyzed by gas chromatography/quadrupole time-of-flight (qTOF MS system/qTOF) electron ionization mass spectrometry (EI-MS).

RESULTS

Eight metabolites of methoxyisoflavone and six metabolites of ipriflavone were isolated. The corresponding accurate mass spectra are specific for isoflavone structures and revealed also a retro-Diels-Alder fragmentation.

CONCLUSIONS

When excreted in large amounts, the urinary metabolites of methoxyisoflavone and ipriflavone can be traced to potential confounding factors in doping analysis. As methoxyisoflavone and ipriflavone have been shown to inhibit the enzyme aromatase, thus interfering with the normal metabolic pathways of testosterone, the detection of their intake, by screening for the presence of their main metabolites in urine, might be helpful in routine doping control analysis.

Understanding the Use of Dietary Supplements among Athlete and Non-Athlete University Students: Development and Validation of a Questionnaire

BACKGROUND

The purpose of this study is to develop and test the validity and reliability of a questionnaire to evaluate dietary supplement use based on the Theory of Planned Behaviour (TPB).

METHODS

The questionnaire has sections on demographics, physical activity, dietary supplements, and cognitive constructs based on the TPB. Three stages are followed. In Stage 1, elicitation interviews are conducted on five varsity athletes, five physically active non-athletes, and five physically inactive University of Guelph (UofG) students. In Stage 2, comments and ratings of the TPB-based statements are gathered from 10 subject matter experts to check for content validity. In Stage 3, Cronbach's α is calculated to determine the internal consistency of the cognitive constructs by a pilot test on 84 Applied Human Nutrition UofG students.

RESULTS

Interviews assisted in the formulation of the cognitive constructs' statements, including intentions, attitudes, injunctive norms, descriptive norms, and perceived behavioural control. Content validity ensured that these constructs did not overlap. Few statements from the cognitive constructs were omitted based on findings from the reliability test, achieving acceptable Cronbach's α values across all constructs (≥0.70).

CONCLUSIONS

This supplement use questionnaire will be used in a future study to investigate the use and determinants of dietary supplements among Canadian athlete and non-athlete UofG students.

Sports Foods and Dietary Supplements for Optimal Function and Performance Enhancement in Track-and-Field Athletes

Athletes are exposed to numerous nutritional products, attractively marketed with claims of optimizing health, function, and performance. However, there is limited evidence to support many of these claims, and the efficacy and safety of many products is questionable. The variety of nutritional aids considered for use by track-and-field athletes includes sports foods, performance supplements, and therapeutic nutritional aids. Support for sports foods and five evidence-based performance supplements (caffeine, creatine, nitrate/beetroot juice, β-alanine, and bicarbonate) varies according to the event, the specific scenario of use, and the individual athlete's goals and responsiveness. Specific challenges include developing protocols to manage repeated use of performance supplements in multievent or heat-final competitions or the interaction between several products which are used concurrently. Potential disadvantages of supplement use include expense, false expectancy, and the risk of ingesting banned substances sometimes present as contaminants. However, a pragmatic approach to the decision-making process for supplement use is recommended. The authors conclude that it is pertinent for sports foods and nutritional supplements to be considered only where a strong evidence base supports their use as safe, legal, and effective and that such supplements are trialed thoroughly by the individual before committing to use in a competition setting.

Making Decisions About Supplement Use

The use of dietary supplements is widespread among athletes in all sports and at all levels of competition, as it is in the general population. For the athlete training at the limits of what is sustainable, or for those seeking a shortcut to achieving their aims, supplements offer the prospect of bridging the gap between success and failure. Surveys show, however, that this is often not an informed choice and that the knowledge level among consumers is often low and that they are often influenced in their decisions by individuals with an equally inadequate understanding of the issues at stake. Supplement use may do more harm than good, unless it is based on a sound analysis of the evidence. Where a deficiency of an essential nutrient has been established by appropriate investigations, supplementation can provide a rapid and effective correction of the problem. Supplements can also provide a convenient and time-efficient solution to achieving the necessary intake of key nutrients such as protein and carbohydrate. Athletes contemplating the use of supplements should consider the potential for both positive and negative outcomes. Some ergogenic supplements may be of benefit to some athletes in some specific contexts, but many are less effective than is claimed. Some may be harmful to health of performance and some may contain agents prohibited by anti-doping regulations. Athletes should make informed choices that maximize the benefits while minimizing the risks.

Medication and Supplement Use in Disability Football World Championships

BACKGROUND

Individuals with an impairment comprise more than 15% of the world's population, many of whom can benefit greatly from participation in sport. The provision of medical services in disability sport is a challenging area with a lack of scientific evidence. Given the positive impact that sport can have on the people with an impairment, it is vital that measures are taken to better understand the medical issues posed by disability sport. It is well established that medications and supplements are overused in sport, particularly within professional football, but there is no current evidence on medication or supplement use in elite disability football.

OBJECTIVE

To examine and describe the use of medication and supplements in disability football, before and during international tournaments, and to identify the profile of substances used by category.

DESIGN

Prospective, descriptive, cohort study.

SETTING

International Blind Sport Association Football World Cup 2015 and the International Federation of Cerebral Palsy Football World Cup 2015.

PARTICIPANTS

Two hundred forty-two elite-level disability footballers, classified with B1 visual impairment or cerebral palsy.

METHODS

Team clinicians were asked to document all medication and supplements taken in the 48 hours before each match.

RESULTS

This study recorded the use of 1648 substances in 242 players, with more than one half (53.1%) classified as supplements. There was an overall rate of 1.26 substances used per player per match and a medication use rate of 0.59 medications per player per match. Seventy percent (170/242) of players reported using at least one substance per tournament, with 57.9% (140/242) using at least one prescribed medication (63.6% of players at International Blind Sports Association World Games and 57.7% of players at International Federation of Cerebral Palsy World Cup). The most commonly prescribed category of medications was nonsteroidal anti-inflammatory drugs, representing 39.3% of all reported medications.

CONCLUSION

This study highlights the potential overuse of medication and supplements in disability football, particularly in the use of nonsteroidal anti-inflammatory drugs. These trends are comparable to previous research in Fédération Internationale de Football Association World Cup competitions.

LEVEL OF EVIDENCE

Not applicable.

Ephedra alkaloid contents of Chinese herbal formulae sold in Taiwan

Consumption of Ephedra alkaloids is prohibited in-competition by the World Anti-Doping Agency (WADA). In Taiwan, colds are often treated with Chinese herbal formulae containing Herba Ephedrae. We screened products sold in Taiwan and preliminarily assessed their relationships with WADA threshold violations. Fifty-six concentrated powder products, including 19 Chinese herbal formulae that contained Herba Ephedrae, were collected. The content of Ephedra alkaloids, namely ephedrine (E), methylephedrine (ME), norpseudoephedrine (NPE; cathine), pseudoephedrine (PE), and norephedrine (NE; phenylpropanolamine), was determined using a validated high-performance liquid chromatography method. The results revealed that the phenotypic indicators of the collected products, E/PE and E/total ratios, were 1.52-4.70 and 0.49-0.72, respectively, indicating that the Herba Ephedrae species in these products was probably E. sinica or E. equisetina, but not E. intermedia. The contents of E, ME, NPE, PE, and NE and the total alkaloid contents in the daily doses of the products were 0.45-34.97, 0.05-4.87, 0.04-3.61, 0.15-12.09, and 0.01-2.00 mg and 0.68-53.64 mg, respectively. The alkaloid contents followed a relatively consistent order (E > PE > ME ≈ NPE > NE), even for products from different manufacturers. We calculated that single doses of 50.0% and 3.6% of the products would result in the WADA thresholds of E and NPE being exceeded, respectively. Our data provide critical information for athletes and medical personnel, who should be wary of using complex Chinese herbal formulae in addition to over-the-counter products.

The new front in the war on doping: Amateur athletes

The war on drugs is usually associated with criminal policies aimed at stemming consumption of drugs such as heroin, cocaine, and cannabis, less so with enhancement drugs like those used in sport. As drug use in sport, or doping, has become more visibly widespread, policies aimed at combating the issue have become more restrictive, intrusive, and harsh. In this article we draw new comparisons between the wider war on drugs and recent developments in sports anti-doping. We identify a growing trend towards criminalisation of traffickers and users, and associate that with another growing trend: the testing of amateur athletes. This article reviews the current anti-doping system, including the recent amateur policies, then considers of the results of one such program in amateur cycling. We then shift to consider the possible implications for amateurs of criminal doping laws and the recent debates about allowing medical exemptions for therapeutic use of banned substances. We show that drug use in sport can be understood as a new front in the war on drugs, with some extreme measures and many negative unintended consequences. To remedy this, we argue that amateur athletes require a separate anti-doping policy focused on minimising harms of use.

Proteomics in quality control: Whey protein-based supplements

The growing consumption of nutritional supplements might represent a problem, given the concern about the quality of these supplements. One of the most used supplements is whey protein (WP); because of its popularity, it has been a target of adulteration with substitute products, such as cheaper proteins with lower biological value. To investigate this type of adulteration, this study used shotgun proteomics analyses by MS(E) (multiplexed, low- and high-collision energy, data-independent acquisition) of WP-based supplements. Seventeen WP-based supplement samples were evaluated. Chicken, maize, rice, potato, soybean, and wheat proteins were considered as probable sources of bovine whey adulteration. Collectively, 523 proteins were identified across all 16 samples and replicates, with 94% of peptides inside a normal distribution within 10ppm of maximum error. In 10 of the 16 samples analyzed, only proteins from bovine whey could be detected, while in the other samples several other protein sources were detected in high concentrations, especially soybean, wheat, and rice. These results point out a probable adulteration and/or sample contamination during manufacturing that could only be detected using this proteomic approach.

SIGNIFICANCE

The present work shows how shotgun proteomics can be used to provide reliable answers in quality control matters, especially focusing on Whey Protein nutritional supplements which are a very popular subject in food and nutrition. In order to achieve an appropriate methodology, careful evaluation was performed applying extremely rigorous quality criteria, established for the proteomic analysis. These criteria and the methodological approach used in this work might serve as a guide for other authors seeking to use proteomics in quality control.

How the Iranian Football Coaches and Players Know About Doping?

Background:

Nowadays, doping is an intricate dilemma. Football is the nationally popular sport in Iran. On the other hand, doping is a serious health hazard sport faces today. Studies dealing with athletes’ knowledge, attitudes and behavior concerning doping in football are scarce.

Objectives:

Therefore, we aimed to investigate the knowledge and attitudes toward doping among the football coaches and players.

Patients and Methods:

In a cross sectional study, 375 participants (239 football players and 136 coaches) were studied. A specially made questionnaire was applied. In this study, football teams of different provinces of the country were selected by randomized clustered sampling and questionnaires were distributed among coaches and players.

Results:

Knowledge of football coaches and players in three categories of doping definitions, recognition of prohibited drugs and side effects of anabolic steroids was poor or moderate in 45.3%, 88.5% and 96.5%, respectively.

Conclusions:

Football players and coaches have poor knowledge about doping in Iran. Moreover, they believe in some inappropriate myths without any scientific or rational basis.It seems necessary to design a comprehensive educational program for all of the athletes and coaches in Iran.

Should nutritional supplements and sports drinks companies sponsor sport? A short review of the ethical concerns

This paper proposes that the sponsorship of sport by nutritional supplements and sport drinks companies should be re-examined in the light of ethical concerns about the closeness of this relationship. A short overview is provided of the sponsorship of sport, arguing that ethical concerns about its appropriateness remain despite the imposition of severe restrictions on tobacco sponsorship. Further, the paper examines the main concerns about supplement use and sports drinks with respect to efficacy, health and the risks of doping. Particular consideration is given to the health implications of these concerns. It is suggested that they, of themselves, do not warrant the restriction of sponsorship by companies producing supplements and sports drinks. Nevertheless, it is argued that sports sponsorship does warrant further ethical examination--above and beyond that afforded to other sponsors of sport--as sport sponsorship is integral to the perceived need for such products. In conclusion, it is argued that sport may have found itself lending unwarranted credibility to products which would otherwise not necessarily be seen as beneficial for participation in sports and exercise or as inherently healthy products.

Health Culture and Running: Non-Elite Runners' Understandings of Doping and Supplementation

Participants at the non-elite level of road running often take up the sport for purposes of health, as a way of taking responsibility for their own well-being. Often, these runners use dietary supplements as a way to improve health and to potentially enhance running performance. Supplements are distinct from banned performance enhancing drugs (PEDs), as they are legal and widely available, though very loosely regulated. Research demonstrates that the line between supplements and banned PEDs is increasingly blurry as cases of cross-contaminated and mislabeled supplements continue to be found. Such products may pose health risks to unsuspecting consumers. Despite anti-doping agencies' warnings to elite runners about these risks, non-elite runners are rarely told by any sport or anti-doping body to be wary of supplements. They are, however, inundated with media coverage of doping scandals usually involving only a few of the substances banned in sport. In short, these runners are often left to navigate supplement use on their own and many conflate supplement availability with safety. This article explores these routine dietary supplement practices among non-elite runners. Drawing from interviews with 28 non-elite runners in New York City, I discuss the perceptions and understandings of doping and dietary supplement use within the context of health culture. Interview data reveal that the social acceptance of dietary supplements and their widespread use among the broader public reinforce the notion among non-elite runners that such products are objectively safe and healthy. I argue that based on their assumptions of supplement safety, non-elite runners view dietary supplements as distinctly different from PEDs and that this difference encourages their use as health and performance aids.

Nutrition for tennis: practical recommendations

Tennis is a pan-global sport that is played year-round in both hemispheres. This places notable demands on the physical and psychological preparation of players and included in these demands are nutritional and fluid requirements both of training and match- play. Thus, the purpose of this article is to review nutritional recommendations for tennis. Notably, tennis players do not excel in any particular physiological or anthropometric characteristic but are well adapted in all areas which is probably a result of the varied nature of the training demands of tennis match play. Energy expenditures of 30.9 ± 5.5 and 45.3 ± 7.3 kJ·min(-1) have been reported in women and men players respectively regardless of court surface. Tennis players should follow a habitually high carbohydrate diet of between 6-10 g·kg(-1)·d(-1) to ensure adequate glycogen stores, with women generally requiring slightly less than men. Protein intake guidelines for tennis players training at a high intensity and duration on a daily basis should be ~1.6 g·kg(-1)·d(-1) and dietary fat intake should not exceed 2 g·kg(-1)·d(-1). Caffeine in doses of 3 mg·kg(-1) provides ergogenic benefit when taken before and/or during tennis match play. Depending on environmental conditions, sweat rates of 0.5 to and over 5 L·hr(-1) and sodium losses of 0.5 - 1.8 g have been recorded in men and women players. 200 mL of fluid containing electrolytes should be consumed every change-over in mild to moderate temperatures of < 27°C but in temperatures greater than 27°C players should aim for ≤ 400 mL. 30-60 g·hr(-1) of carbohydrate should be ingested when match play exceeds 2 hours. Key PointsTennis players should follow a habitually high carbohydrate diet of between 6-10 g·kg(-1) to ensure adequate glycogen stores, with women generally requiring slightly less than men. Protein intake guidelines for tennis players training at a high intensity and duration on a daily basis should be ~1.6 g·kg(-1)·d(-1). Dietary fat intake should not exceed 2 g·kg(-1)·d(-1).Caffeine in doses of 3 mg·kg(-1) can provide ergogenic benefit when taken before and/or during tennis match play.200 mL of fluid containing electrolytes should be consumed every change-over in mild to moderate temperatures of < 27°C but in temperatures greater than 27°C players should aim for ≥ 400 mL.30-60 g·hr(-1) of carbohydrate should be ingested when match play exceeds 2 hours.During periods of travel, specific dietary requirements can be communicated with agencies and hotels prior to arrival and in the event that suitably nutritious foods are not available in the host country, players can bring or send non-perishable foods and goods where customs and quarantine laws allow.

Doping awareness, views, and experience: a comparison between general practitioners and pharmacists

PURPOSE

Information about doping awareness among medical professionals is scarce. We evaluated the attitudes, level of knowledge and experience among general practitioners (GPs) and pharmacists (Ps) with regard to doping.

METHODS

In a cross-sectional national survey a 59-item self-administered questionnaire was sent to a representative random sample of 645 GPs and 330 Ps.

RESULTS

Overall, 204/975 (133 GPs, 71 Ps) questionnaires were returned and available for analysis. Fewer than half (39% GPs vs. 48% Ps, P = 0.702) of respondents were familiar with the formal definition of doping. The abbreviation WADA was correctly interpreted by 42% (33% vs. 59%, P = 0.003), and 65% knew that the European Commission has the legislation to fight against doping. More GPs (69% vs. 31%, P = 0.005) agreed to have a role to play in doping prevention, similar proportions considering themselves to have sufficient knowledge of prevention initiatives (65% vs. 35%, P = 0.369). Overall, 12% of respondents (8.7% GPs, 19.3% Ps) reported being directly confronted with a request for prescription of doping agents in the previous 12 months (mainly stimulants, anabolic agents, hormones, corticosteroids).

CONCLUSIONS

GPs and Ps are frequently exposed to questions about and requests for doping agents. They have acceptable level of general knowledge but are in need for more specific information on prohibited substances and legislature.

Gateway to doping? Supplement use in the context of preferred competitive situations, doping attitude, beliefs, and norms

Nutritional supplement (NS) use is widespread in sport. This study applied an integrated social cognitive approach to examine doping attitudes, beliefs, and self-reported doping use behavior across NS users (n = 96) and nonusers (n = 116). Following ethical approval, 212 competitive athletes (age mean = 21.4, s = 4.5; 137 males) completed self-reported measures of doping-related social cognitions and behaviors, presented in an online format where completion implied consent. Significantly more NS users (22.9%) reported doping compared with nonusers (6.0%; U = 4628.0, P < 0.05). NS users presented significantly more positive attitudes toward doping (U = 3152.0, P < 0.05) and expressed a significantly greater belief that doping is effective (U = 3152.0, P < 0.05). When presented with the scenario that performance-enhancing substances are effective and increase the possibility of winning, NS users were significantly more in favor of competing in situations that allow doping (U = 3504.5, P < 0.05). In sum, doping use is three-and-a-half times more prevalent in NS users compared with nonusers. This finding is accompanied by significant differences in doping attitudes, norms, and beliefs. Thus, this article offers support for the gateway hypothesis; athletes who engage in legal performance enhancement practices appear to embody an "at-risk" group for transition toward doping. Education should be appropriately targeted.

The role of banned substance residue analysis in the control of dietary supplement contamination

The potential for contaminated dietary supplements to result in a failed doping test remains a concern for athletes, trainers, and sporting authorities despite improvements to regulatory guidelines. Previous surveys of readily available supplements confirm that many are contaminated with steroids and stimulants prohibited for use in elite sport. Suggested responses to this issue include the complete avoidance of all supplements. Many athletes, however, use nutritional supplements to achieve effective training and also to ensure that daily nutritional requirements are met (e.g. recommended levels of vitamins and minerals). This ensures that the use of supplements is and will remain the norm for a range of sports. As a result, an alternative approach of rigorous testing of materials destined for use by elite athletes has been introduced in several countries. While the testing of final product for banned substances may help mitigate the problem, it will not help to remove the underlying issue of contamination. In this article we describe an alternative approach that uses appropriate quality assurance procedures backed up by testing to remove sources of contamination. The decrease in the incidence of contamination amongst supplement companies adopting such a system is explained, and contrasted with the relatively high incidences of contamination found in products that are not part of a quality system. These findings are of key importance to both supplement manufacturers and those involved in advising athletes about supplement use.

Use of dietary supplements in Olympic athletes is decreasing: a follow-up study between 2002 and 2009

Background

The aim of this study was to assess the frequency of use of dietary supplements (DS) among large sample of elite Finnish athletes and to describe possible changes in dietary supplement use between the years 2002 and 2009.

Methods

A prospective follow-up study was conducted on Olympic athletes. The first survey was conducted on Olympic athletes in 2002 (N = 446) and the follow-up study was conducted between May 2008 and June 2009 (N = 372).

Results

In 2002, a total of 81% of the athletes used dietary supplements (a mean of 3.37 ± 3.06 DS per user) and in 2009, a total of 73% of the athletes (a mean of 2.60 ± 2.69 per DS user) used them. After adjusting for age-, sex- and sport type, the OR (95% confidence interval, CI) for use of any dietary supplement was significantly less in 2009 as compared with 2002 results (OR, 0.62; 95% CI, 0.43-0.90). Decrease in DS use was observed in all supplement subgroups (vitamins, minerals, nutritional supplements). Athletes in speed and power events and endurance events reported use of any dietary supplement significantly more often than team sport athletes both in 2002 and 2009. In year 2009, the frequency of all dietary supplement use increased when athlete's age increased and the increase was significant in older age groups: of the athletes under 21 years 63%, 21-24 years 83% and over 24 years 90% consumed nutritional supplements.

Conclusions

Based in our study, there seems to be a lowering trend of dietary supplement use among elite Finnish athletes although differences between sport subgroups and age groups are considerable.

Epidemiological analysis of doping offences in the professional tennis circuit

Introduction

Tennis is a professional sport under a strict anti-doping control. However, since the first violation of the code, the positive cases have not been statistically studied. The objective of this study was to analyze doping offences in the international professional tennis circuit.

Methods

All offences to the Doping Code committed by tennis players during 2003-2009 were collected from the ITF official webpage, registered and analyzed.

Results

An average of 1905.7 (±174.5) samples was obtained per year. Fifty-two doping offences were reported and the overall incidence of positive doping samples accounted for 0.38% and 7.4 (±4.1) cases/year. Male players showed higher incidence doping offences than females (p = 0.0004). The incidence in wheelchair players was higher than in non-handicapped subjects (p = 0.0001)

Banned substance distribution showed: stimulants 32.69%, cannabis 23.07%; anabolic 11.53%, diuretics and masking agents 11.53, β2-agonists 9.61%; corticosteroids 3.84%, others 3.84%. The overall incidence of 'social drugs' (cocaine, cannabis) was 36.53%. All EPO and blood samples were normal, while the incidence of 'out-of-competition' offences was 0.12%. The lower incidence of doping was found in Grand Slams tournaments.

Conclusions

The incidence of positive doping samples among professional tennis players is quite low supporting the assumption that there is no evidence of systematic doping in Tennis. "Social drugs" misuse constitutes the main problem of doping in tennis. Male and wheelchair tennis players showed higher risk of infringing the doping code than their females and non-handicapped counterparts. Findings of this study should help to determine the direction of the ongoing strategy in the fight against doping in Tennis.

Substance use and misuse among Slovenian table tennis players

Substance use and misuse (SU&M) is regularly studied in sports, but we have found no such data for table tennis. We have studied SU&M in athletes competing at the Slovenian Nationals 2008-2009 (responding rate was 100%; 50 males and 29 females; aged 18 years or older). The anonymous questionnaire for studying SU&M and corresponding educational, socio-demographic, and sport factors was used. More than 90% of all the athletes included in our study do not rely on coaches' and/or physicians' opinion regarding nutritional supplements and doping. Chi-square test revealed higher prevalence of binge drinking, cigarette smoking, and potential doping behavior in males. In both genders, with the advancement of the sport status, the probability for potential doping behavior increases. In conclusion, we strongly suggest permanent SU&M educational programs for table tennis athletes as well as for their coaches and physicians.

Nandrolone: a multi-faceted doping agent

Nandrolone or nortestosterone, an anabolic-androgenic steroid, has been prohibited by doping control regulations for more than 30 years. Although its main metabolism in the human body was already known at that time, and detection of its misuse by gas or liquid chromatographic separation with mass spectrometric detection is straightforward, many interesting aspects regarding this doping agent have appeared since.Over the years, nandrolone preparations have kept their position among the prohibited substances that are most frequently detected in WADA-accredited laboratories. Their forms of application range from injectable fatty acid esters to orally administered nandrolone prohormones. The long detection window for nandrolone ester preparations and the appearance of orally available nandrolone precursors have changed the pattern of misuse.At the same time, more refined analytical methods with lowered detection limits led to new insights into the pharmacology of nandrolone and revelation of its natural production in the body.Possible contamination of nutritional supplements with nandrolone precursors, interference of nandrolone metabolism by other drugs and rarely occurring critical changes during storage of urine samples have to be taken into consideration when interpreting an analytical finding.A set of strict identification criteria, including a threshold limit, is applied to judge correctly an analytical finding of nandrolone metabolites. The possible influence of interfering drugs, urine storage or natural production is taken into account by applying appropriate rules and regulations.

Caffeine Supplementation and muscle damage in soccer players

The aim of this work was to evaluate the effect of caffeine supplementation and intermittent exercise on the muscle injury markers in soccer players. 15 male professional soccer players completed a placebo controlled double blind test protocol. 45 minutes before exercise, participants ingested 5.5 mg.kg-1 body mass of caffeine (EXP, n=8) or placebo (CONT, n=7). The exercise was 12 sets of 10 sprints (20 m each) with 10 sec recovery time between sprints and 2 min between sets. Blood samples were collected before (PRE) and 48h after exercise (POST). Serum activity of CK, LDH, AST, and ALT were quantified. Serum enzyme activity was enhanced by exercise in both groups, without a synergistic effect of caffeine. The findings suggest muscle injury markers concentration increases after physical activities, but caffeine supplementation (as used in this study) has no influence upon muscle cellular integrity.

Doping use among young elite cyclists: a qualitative psychosociological approach

Using a psychosociological approach, the purpose of this study was to identify and understand the use of doping substances by young elite cyclists. Semi-structured interviews were conducted with young cyclists who were hoping to find a professional team and cyclists who had recently become professional. All of the young cyclists interviewed took nutritional supplements and believed that they improved their performance, which has been shown by other scholars to be a risk factor for doping. These cyclists believed that doping at the professional level in cycling was acceptable but did not approve of it at the amateur level. They were attracted to doping; they were open to using doping substances themselves if it was the key to continuing their cycling career, but only after they became professional. Team staff, doctors, parents and friends helped to create a "clean" environment that prevented the young cyclists from doping before becoming professional. The more experienced cyclists, who doped or used to dope, transmitted the culture of doping to the young cyclists, teaching them doping methods and which substances to use. This study could help to improve prevention and help to detect doping, as it is clear that doping behaviors begin at the amateur level.

Nutritional supplements cross-contaminated and faked with doping substances

Since 1999 several groups have analyzed nutritional supplements with mass spectrometric methods (GC/MS, LC/MS/MS) for contaminations and adulterations with doping substances. These investigations showed that nutritional supplements contained prohibited stimulants as ephedrines, caffeine, methylenedioxymetamphetamie and sibutramine, which were not declared on the labels. An international study performed in 2001 and 2002 on 634 nutritional supplements that were purchased in 13 different countries showed that about 15% of the nonhormonal nutritional supplements were contaminated with anabolic-androgenic steroids (mainly prohormones). Since 2002, also products intentionally faked with high amounts of 'classic' anabolic steroids such as metandienone, stanozolol, boldenone, dehydrochloromethyl-testosterone, oxandrolone etc. have been detected on the nutritional supplement market. These anabolic steroids were not declared on the labels either. The sources of these anabolic steroids are probably Chinese pharmaceutical companies, which sell bulk material of anabolic steroids. In 2005 vitamin C, multivitamin and magnesium tablets were confiscated, which contained cross-contaminations of stanozolol and metandienone. Since 2002 new 'designer' steroids such as prostanozol, methasterone, androstatrienedione etc. have been offered on the nutritional supplement market. In the near future also cross-contaminations with these steroids are expected. Recently a nutritional supplement for weight loss was found to contain the beta2-agonist clenbuterol. The application of such nutritional supplements is connected with a high risk of inadvertent doping cases and a health risk. For the detection of new 'designer' steroids in nutritional supplements, mass spectrometric strategies (GC/MS, LC/MS/MS) are presented.