Probing the hair detectability of prohibited substances in sports: an in vivo-in silico-clinical approach and analytical implications compared with plasma, urine, and faeces.

Hair analysis is a crucial method in forensic toxicology with potential applications in revealing doping histories in sports. Despite its widespread use, knowledge about detectable substances in hair is limited. This study systematically assessed the detectability of prohibited substances in sports using a multifaceted approach. Initially, an animal model received a subset of 17 model drugs to compare dose dependencies and detection windows across different matrices. Subsequently, hair incorporation data from the animal experiment were extrapolated to all substances on the World Anti-Doping Agency's List through in-silico prediction. The detectability of substances in hair was further validated in a proof-of-concept human study involving the consumption of diuretics and masking agents. Semi-quantitative analysis of substances in specimens was performed using ultra-performance liquid chromatography-tandem mass spectrometry. Results showed plasma had optimal dose dependencies with limited detection windows, while urine, faeces, and hair exhibited a reasonable relationship with the administered dose. Notably, hair displayed the highest detection probability (14 out of 17) for compounds, including anabolic agents, hormones, and diuretics, with beta-2 agonists undetected. Diuretics such as furosemide, canrenone, and hydrochlorothiazide showed the highest hair incorporation. Authentic human hair confirmed diuretic detectability, and their use duration was determined via segmental analysis. Noteworthy is the first-time reporting of canrenone in human hair. Anabolic agents were expected in hair, whereas undetectable compounds, such as peptide hormones and beta-2 agonists, were likely due to large molecular mass or high polarity. This study enhances understanding of hair analysis in doping investigations, providing insights into substance detectability.

Inhaled beta2 -agonist, formoterol, enhances intense exercise performance, and sprint ability in elite cyclists.

PURPOSE: Many athletes use long-acting beta2 -agonist formoterol in treatment of asthma. However, studies in non-athlete cohorts demonstrate that inhaled formoterol can enhance sprint performance calling into question whether its use in competitive sports should be restricted. We investigated whether formoterol at upper recommended inhaled doses (54 µg) would enhance sprint ability and intense exercise performance in elite cyclists. METHODS: Twenty-one male cyclists (V̇O2max : 70.4 ± 4.3 mL × min-1 × kg-1 , mean ± SD) completed two 6-s all-out sprints followed by 4-min all-out cycling after inhaling either 54 µg formoterol or placebo. We also assessed cyclists' leg muscle mass by dual-energy X-ray absorptiometry and muscle fiber type distribution of vastus lateralis biopsies. RESULTS: Peak and mean power output during the 6-s sprint was 32 W (95% CI, 19-44 W, p < 0.001) and 36 W (95% CI, 24-48 W, p < 0.001) higher with formoterol than placebo, corresponding to an enhancing effect of around 3%. Power output during 4-min all-out cycling was 9 W (95% CI, 2-16 W, p = 0.01) greater with formoterol than placebo, corresponding to an enhancing effect of 2.3%. Performance changes in response to formoterol were unrelated to cyclists' VO2max and leg lean mass, whereas muscle fiber Type I distribution correlated with change in sprinting peak power in response to formoterol (r2 = 0.314, p = 0.012). CONCLUSION: Our findings demonstrate that an inhaled one-off dose of 54 µg formoterol has a performance-enhancing potential on sprint ability and short intense performance in elite male cyclists, which is irrespective of training status but partly related to muscle fiber type distribution for sprint ability.

Sample Preparation Techniques for Growth-Promoting Agents in Various Mammalian Specimen Preceding MS-Analytics.

The misuse of growth-promoting drugs such as beta-2 agonists and steroids is a known problem in farming and sports competitions. Prior to the analysis of biological samples via liquid chromatography (LC)-mass spectrometry (MS) or gas chromatography (GC)-MS, sufficient sample preparation is required to reliably identify or determine the residues of drugs. In practice, broad screening methods are often used to save time and analyze as many compounds as possible. This review was conceptualized to analyze the literature from 2018 until October 2023 for sample preparation procedures applied to animal specimens before LC- or GC-MS analysis. The animals were either used in farming or sports. In the present review, solid phase extraction (SPE) was observed as the dominant sample clean-up technique for beta-2 agonists and steroids, followed by protein precipitation. For the extraction of beta-2 agonists, mixed-mode cation exchanger-based SPE phases were preferably applied, while for the steroids, various types of SPE materials were reported. Furthermore, dispersive SPE-based QuEChERs were utilized. Combinatory use of SPE and liquid-liquid extraction (LLE) was observed to cover further drug classes in addition to beta-2 agonists in broader screening methods.

Detection of synthetic analogues of insulin-like growth factor 1 in different biological fluids by liquid chromatography quadrupole time-of-flight mass spectrometry: comparison of different immunoaffinity protocols.

Insulin-like growth factor 1 analogues are prohibited in sport for their ability to enhance athletic performance in several sport disciplines. Their detection presents several analytical challenges, mainly due to the minimum required performance limits fixed by the World Anti-Doping Agency. Here, we are presenting analytical workflows to detect IGF-1 and its analogues in different biological matrices. Several off-line immunocapture techniques and protocols were comparatively evaluated. Separation and detection were performed by using standard flow reverse-phase liquid chromatography coupled to a time-of-flight mass spectrometer. The best recoveries were obtained using magnetic beads or pipette tips functionalized with protein A. The analytical workflows were fully validated for qualitative determinations: all the target analytes were clearly distinguishable from the interference of the matrices, with limits of detection and identification in the range of 0.05-0.30 ng/mL in urine and 0.5-2.0 ng/mL in serum/plasma. The extraction efficiency proved to be repeatable (CV% < 10) with recoveries higher than 50%. Intra- and inter-day precision were found to be smaller than 10 and 15%, respectively. The method was successfully applied to the analysis of authentic matrix samples containing the target peptides at the minimum required performance limits, proving that the method developed can be successfully applied to detect and identify IGF-1 analogues for doping control purposes in all the matrices selected. The analytical workflow developed here to detect the target peptides in different matrices can be readily implemented in anti-doping laboratories and has the potential to be adapted for the simultaneous analysis of different similarly sized peptide hormones of doping relevance.

Are Dietary Supplements a Gateway to Doping? A Retrospective Survey of Athletes' Substance Use.

Background: It is proposed that the use of dietary supplements might lead to the use of doping substances. This has been termed the gateway hypothesis. However, within an athletic sample, no research has examined the order in which these substances are consumed and what may explain the progression from dietary supplement use to doping. Objective: To identify whether dietary supplement use precedes doping and examine what moderates the dietary supplement-doping relationship. Methods: Competitive athletes (N=1,081, 42.0% female; Age=29.3±10.8 years) completed an online survey measuring dietary supplement use, doping use, doping subjective norms and age of using a supplement and/or doping substance. Results: Dietary supplement users were 11 times more likely to dope than non-users (OR=11.28, 95% CI = 2.72 to 46.77). Age for first use of a dietary supplement was younger than use of a doping substance (mean difference=-4.5±5.1 years old, p<0.001, d=0.90). Over three-quarters of doping users reported using a dietary supplement first (77.1%), whereas a small proportion of athletes started using dietary supplements and doping at the same time (12.5%) and some used doping substances before using dietary supplements (10.4%). Moderation analysis revealed that dietary supplement users may be more likely to dope because of a more favourable social acceptance of using prohibited substances than non-users. Conclusions: Data suggest that dietary supplement use is more likely to precede doping. However, not all doping users begin with using dietary supplements, which highlights the importance of measuring the temporal order of dietary supplement and doping use in future research.

Assessing anti-doping knowledge among Taiwanese pharmacists.

BACKGROUND: Taiwan's unique health behaviour, such as extensive exposure to Chinese Herbal Medicine (CHM), has introduced a risk of inadvertent doping among competing athletes. Pharmacy professionals have an imperative role in advising athletes on the safe use of medicines. This study provides an overview of anti-doping knowledge and educational needs among pharmacists in Taiwan and examines influencing factors. METHODS: A cross-sectional online questionnaire survey consisting of five domains, namely demographic characteristics, source of prohibited substances, identification of prohibited substances, understanding of doping control, and education needs on anti-doping, was distributed to the registered pharmacists in Taiwan. In total, 491 responses were included in the analyses. RESULTS: Respondents (65% female, aged 41.9 ± 11.4 years, with 68% having a Bachelor's degree) reported a moderate anti-doping knowledge score of 37.2 ± 4.9, ranging from 21 to 48 (out of 51). Fifteen per cent of them had the experience of being counselled about drug use in sports. Higher knowledge scores were observed in younger respondents, showing an age-dependent effect (p < 0.001). Individuals practising in southern Taiwan (compared to northern Taiwan) and those working at clinics (compared to hospitals) exhibited lower knowledge. Most of the respondents (90%) knew that stimulant ephedrine is prohibited in sports, but few had recognised diuretic furosemide (38%) and CHM (7%) containing ß2-agonist higenamine. Approximately 90% of respondents agreed with the need for anti-doping education. CONCLUSIONS: This study highlights the heterogeneity of anti-doping knowledge among pharmacy professionals and provides practical relevance in organising future educational topics and research-based activities.

Contemporary blood doping-Performance, mechanism, and detection.

Blood doping is prohibited for athletes but has been a well-described practice within endurance sports throughout the years. With improved direct and indirect detection methods, the practice has allegedly moved towards micro-dosing, that is, reducing the blood doping regime amplitude. This narrative review evaluates whether blood doping, specifically recombinant human erythropoietin (rhEpo) treatment and blood transfusions are performance-enhancing, the responsible mechanism as well as detection possibilities with a special emphasis on micro-dosing. In general, studies evaluating micro-doses of blood doping are limited. However, in randomized, double-blinded, placebo-controlled trials, three studies find that infusing as little as 130 ml red blood cells or injecting 9 IU × kg bw-1 rhEpo three times per week for 4 weeks improve endurance performance ~4%-6%. The responsible mechanism for a performance-enhancing effect following rhEpo or blood transfusions appear to be increased O2 -carrying capacity, which is accompanied by an increased muscular O2 extraction and likely increased blood flow to the working muscles, enabling the ability to sustain a higher exercise intensity for a given period. Blood doping in micro-doses challenges indirect detection by the Athlete Biological Passport, albeit it can identify ~20%-60% of the individuals depending on the sample timing. However, novel biomarkers are emerging, and some may provide additive value for detection of micro blood doping such as the immature reticulocytes or the iron regulatory hormones hepcidin and erythroferrone. Future studies should attempt to validate these biomarkers for implementation in real-world anti-doping efforts and continue the biomarker discovery.

Practical Efficacy of Prior Checks on Athletes' Medication Use for the Prevention of Unintentional Doping.

Background: Athletes are subjected to disciplinary action for even unintentional doping. This study aimed to clarify the effectiveness of prior checks on athletes' drug regimens by medical personnel with knowledge of anti-doping to prevent unintentional doping. Methods: This is a retrospective evaluation of the inquiries to the Anti-Doping Committee by the Japan Table Tennis Association national team athletes and athlete support personnel between 2011 and 2019 regarding whether the drug in question was permitted and whether it contained any prohibited substance. Discrete evaluations were performed for ethical and over-the-counter drugs, in addition to the evaluation of all drugs. Additionally, we evaluated the drugs according to therapeutic category and World Anti-Doping Agency's classification. Results: Overall, 85/1238 (6.9%) ethical drugs, 49/259 (18.9%) over-the-counter drugs and 134/1497 (9.0%) total drugs were considered as not allowed for use. The proportion of over-the-counter drugs judged as not allowed for use was higher than that of ethical drugs (p < 0.001). When tabulating the drugs not allowed for use in the therapeutic category, numerous prohibited substances were identified in adrenal hormone preparations, Kampo products, synthetic narcotics, antitussives, antihemorrhoidals, and bronchodilators among ethical drugs and in cold remedies, gastrointestinal drugs, and antitussives and expectorants among over-the-counter drugs. Conclusions: Of the ethical and over-the-counter drugs that elite athletes wanted to use, approximately 10% were not allowed because of the risk of unintentional doping. These results suggest that conducting prior checks of the athletes' drug regimens by medical personnel with anti-doping knowledge are effective measures to prevent unintentional doping.

A sensitive HPLC-MS/MS method for the detection, resolution and quantitation of cathinone enantiomers in horse blood plasma and urine.

Resolution of cathinone enantiomers in equine anti-doping analysis is becoming more important to distinguish the inadvertent ingestion of plant-based products from those of deliberate administration of designer synthetic analogs. With this in mind, a rapid and sensitive method was developed and validated for the detection, resolution and quantitative determination of cathinone enantiomers in horse blood plasma and urine. The analytes were recovered from the blood plasma and urine matrices by using a liquid-liquid extraction after adjusting the pH to 9. The recovered analytes were derivatized with Nα-(2,4-dinitro-5-fluorophenyl)-L-valinamide, a chiral derivatizing agent analogous to Marfey's reagent. The resulting diastereoisomers were baseline resolved under a reversed-phase liquid chromatographic condition. Derivatization of the analytes not only allowed the separation of the enantiomers using cost-effective traditional liquid chromatography conditions and reversed-phase columns but also increased the sensitivity, at least to an order of magnitude, when tandem mass spectrometry is used for the detection. A limit of detection of 0.05 ng/mL was achieved for cathinone enantiomers for both matrices. Acceptable intraday and interday precision and accuracy along with satisfactory dilution accuracy and precision were observed during the method validation. The method suitability was tested using the post administration urine samples collected after single doses of cathinone and ephedrine as single-enantiomeric form and methcathinone as racemic form. Finally, a proof of concept of the isomeric ratio in urine samples to distinguish the presence of cathinone as a result of accidental ingestion of plant-based product from that of an illicit use of a designer product is demonstrated. To the best of our knowledge, this is the first such work where cathinone enantiomers were resolved and quantified in horse blood plasma and urine at sub nanogram levels.

Comprehensive insights into the formation of metabolites of the ghrelin mimetics capromorelin, macimorelin and tabimorelin as potential markers for doping control purposes.

Analytical methods to determine the potential misuse of the ghrelin mimetics capromorelin (CP-424,391), macimorelin (macrilen, EP-01572) and tabimorelin (NN703) in sports were developed. Therefore, different extraction strategies, i.e. solid-phase extraction, protein precipitation, as well as a "dilute-and-inject" approach, from urine and EDTA-plasma were assessed and comprehensive in vitro/in vivo experiments were conducted, enabling the identification of reliable target analytes by means of high resolution mass spectrometry. The drugs' biotransformation led to the preliminary identification of 51 metabolites of capromorelin, 12 metabolites of macimorelin and 13 metabolites of tabimorelin. Seven major metabolites detected in rat urine samples collected post-administration of 0.5-1.0 mg of a single oral dose underwent in-depth characterization, facilitating their implementation into future confirmatory test methods. In particular, two macimorelin metabolites exhibiting considerable abundances in post-administration rat urine samples were detected, which might contribute to an improved sensitivity, specificity, and detection window in case of human sports drug testing programs. Further, the intact drugs were implemented into World Anti-Doping Agency-compliant initial testing (limits of detection 0.02-0.60 ng/ml) and confirmation procedures (limits of identification 0.18-0.89 ng/ml) for human urine and blood matrices. The obtained results allow extension of the test spectrum of doping agents in multitarget screening assays for growth hormone-releasing factors from human urine.

Detection of Methylphenidate in Equine Hair Using Liquid Chromatography-High-Resolution Mass Spectrometry.

Methylphenidate is a powerful central nervous system stimulant with a high potential for abuse in horse racing. The detection of methylphenidate use is of interest to horse racing authorities for both prior to and during competition. The use of hair as an alternative sampling matrix for equine anti-doping has increased as the number of detectable compounds has expanded. Our laboratory developed a liquid chromatography-high-resolution mass spectrometry method to detect the presence of methylphenidate in submitted samples. Briefly, hair was decontaminated, cut, and pulverized prior to liquid-liquid extraction in basic conditions before introduction to the LC-MS system. Instrumental analysis was conducted using a Thermo Q Exactive mass spectrometer using parallel reaction monitoring using a stepped collision energy to obtain sufficient product ions for qualitative identification. The method was validated and limits of quantitation, linearity, matrix effects, recovery, accuracy, and precision were determined. The method has been applied to confirm the presence of methylphenidate in official samples submitted by racing authorities.

Inter-Laboratory Agreement of Insulin-like Growth Factor 1 Concentrations Measured Intact by Mass Spectrometry.

BACKGROUND: Insulin-like growth factor-I (IGF-1) is measured mainly by immunoassay for the diagnosis and treatment of growth hormone (GH) disorders, and to detect misuse of GH in sport. Immunoassays often have insufficient inter-laboratory agreement, especially between commercial kits. Over the expected range of IGF-1 in blood (∼50-500 ng/mL), in an inter-laboratory study we previously established a measurement imprecision of 11% (%CV) for the digested protein analyzed by LC-MS. Measuring intact IGF-1 by LC-MS should be simpler. However, no inter-laboratory agreement has been published. METHODS: Intact and trypsin-digested IGF-1 in 32 serum samples from healthy volunteers and human growth hormone administration studies were analyzed by LC-MS using different instruments in five laboratories, as well as by immunoassay in a single laboratory. Another 100 samples were analyzed for IGF-1, both intact and after trypsin-digestion, in each laboratory by LC-MS. The statistical relationship between measurements and the imprecision of each assay group was assessed. RESULTS: An intra-laboratory variability of 2-4% CV was obtained. Inter-laboratory variability was greater at 14.5% CV. Orthogonal regression of intact versus trypsin-digestion methods (n = 646) gave a slope of 1.01 and intercept of 2.05 ng/mL. CONCLUSIONS: LC-MS measurements of IGF-1 by intact and trypsin-digestion methods are not statistically different and each is similar to immunoassay. The two LC-MS approaches may be used interchangeably or together to eliminate concerns regarding an immunoassay IGF-1 measurement. Because intact and digested IGF-1 measurements generally agreed within 20% of each other, we propose this as a criterion of assay acceptability.

Sport-Specific Use of Doping Substances: Analysis of World Anti-Doping Agency Doping Control Tests between 2014 and 2017.

Background: In recent years, there has been a solid effort across all sports organizations to reduce the prevalence and incidence of doping in sport. However, the efficacy of current strategies to fight against doping might be improved by using anti-doping polices tailored to the features of doping in each sport. Objectives: The aim of this investigation was to analyze the substances more commonly found in doping control tests in individual and team sports. Material and Methods: The publicly accessible Testing Figures Reports made available by the World Anti-Doping Agency, were analyzed from 2014 to 2017. Results: The most commonly detected groups of banned substances were anabolic agents and stimulants but the distribution of adverse findings per drug class was very different depending on the sports discipline. Weightlifting, athletics, rugby, hockey and volleyball presented abnormally high proportions of anabolic agents (p = 2.8 × 10-11). Cycling, athletics and rugby presented atypically elevated proportions of peptide hormones and growth factors (p = 1.4 × 10-1). Diuretics and masking agents were more commonly found in boxing, wrestling, taekwondo, judo, shooting, and gymnastics than in other sports (p = 4.0 × 10-68). Cycling, rowing, aquatics, tennis, gymnastics and ice hockey presented abnormally high proportions of stimulants (p = 1.8 × 10-5). Conclusions: These results indicate that the groups of banned substances more commonly detected in anti-doping control tests were different depending on the sports discipline. These data suggest the prohibited substances used as doping agents might be substantially different depending on the type of sport and thus, sports-specific anti-doping policies should be implemented to enhance the efficacy of anti-doping testing.

Dried Urine Microsampling Coupled to Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) for the Analysis of Unconjugated Anabolic Androgenic Steroids.

Testing and monitoring anabolic androgenic steroids in biological fluids is a key activity in anti-doping practices. In this study, a novel approach is proposed, based on dried urine microsampling through two different workflows: dried urine spots (DUS) and volumetric absorptive microsampling (VAMS). Both techniques can overcome some common drawbacks of urine sampling, such as analyte instability and storage and transportation problems. Using an original, validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method, exogenous and endogenous unconjugated steroids were analysed. Despite the limitations of microsampling volume, good sensitivity was obtained (limit of quantitation ≤1.5 ng/mL for all analytes), with satisfactory precision (relative standard deviation <7.6%) and absolute recovery (>70.3%). Both microsampling platforms provide reliable results, in good agreement with those obtained from urine.

Attitude of athletes towards doping: A dilemma in Pakistan.

OBJECTIVES: To evaluate the attitude and of athletes towards performance enhancement through doping and leading reason of their decision for the use of doping in a country. METHODS: This Cross-Sectional descriptive study was conducted with non-probability convenience sampling over a period of six months from November 2018 to May 2019. This study included n=377 National and international athletes/players, of both genders aged 17-35 years, camping for preparation of 13th South Asian Games 2019 at Pakistan Sports Board, Jinnah Complex Islamabad, Pakistan. The athletes/ players with any disease, trauma or working as coaches or officials were excluded. Basic demographic sheet and Athletes Attitude to Doping Questionnaire were used for data collection which was analyzed using SPSS 21. RESULTS: Study revealed significant difference in the Mean and Median scores of the six anti-doping factors with very low scores for "Long Term Health Implications" (Mean= 2.14, Md=2) and "Psychosocial Influences" (Mean=3, Md=3) compared to a high score for the remaining factors, indicating that the participants did not agree these two factors influenced their decision for not doping. Also, there was significant difference in the scores as revealed by Wilcoxon signed test, between Personal Ethical Standards and the remaining factors except Illegality of Substances (z=-1.705, p=0.088). Gender association was noted for anti-doping education and testing, with higher scores in males (p=0.031). Also Type of Main Sport had association with most factors except Long Term Health Implications while Level of Sport did not show any association except for Influence of Significant Others. CONCLUSION: Study concludes that Illegality of Substances and Personal ethical standards are the most significant factor for athletes' decision for not doping.

Detection of recombinant insulins in human urine by liquid chromatography-electrospray ionization tandem mass spectrometry after immunoaffinity purification based on monolithic microcolumns.

This work describes an analytical procedure based on automated affinity purification followed by liquid chromatography-electrospray tandem mass spectrometry with a conventional triple quadrupole analyzer, in order to detect synthetic insulins (Apidra®, Humalog®, Levemir®, NovoRapid®, and Tresiba®) in human urine. Sample preparation included ultrafiltration followed by immunoaffinity purification on monolithic microcolumns. Chromatographic separation was performed by a C18 microbore column, while mass spectrometric identification of the analytes was achieved by a triple quadrupole mass spectrometer under positive ion electrospray ionization and acquisition mode in selected reaction monitoring. Identification of the synthetic insulins was performed by selecting at least two characteristic ion transitions for each analyte. The newly developed method was validated in terms of specificity, recovery, matrix effect, sensitivity, robustness, and repeatability of retention times and relative ion transition abundance. The specificity and the reproducibility of the relative retention times and the relative abundance of the characteristic ion transitions selected was confirmed to be fit for purposes of ensuring the unambiguous identification of all target analytes, also in the forensic field. The extraction yield was estimated at greater than 60% and the matrix effect smaller than 35%. The lower limits of detection were in the range of 0.02-0.05 ng/mL, proving the method to be sufficiently sensitive to detect the abuse of insulins in cases where they are used as performance-enhancing agents in sport. The applicability of the developed method was assessed by the analysis of urine samples obtained from diabetic subjects treated with Tresiba® and/or Humalog®, whose presence was confirmed in urine samples collected after the administration of therapeutic doses. Graphical abstract A hybrid assay comprising MSIA-based immunoextraction combined with liquid chromatography-electrospray tandem mass spectrometry was developed and validated for the detection of recombinant insulins in human urine.

[Doping in elite and popular sport : What orthopedic and trauma surgeons should know]. / Doping im Spitzen- und Breitensport : Was der Orthopäde und Unfallchirurg wissen sollten.

The spectacular doping raid during the Nordic World Ski Championships in Seefeld in winter this year is not the first time that illegal performance enhancement by taking drugs is in the spotlight of public interest. Kicked off by the so-called Festina scandal of the 1998 Tour de France, the serial exposure of further doping offences continues up to the present day. Less well-known to the general public is the high prevalence of doping under hobby and amateur athletes. Physicians are confronted by this group of patients in the practice much more frequently than by elite athletes, who are mostly treated in closed medical networks. The aim of the article is to provide an overview of the medical aspects including the most frequent substance classes and the current legal foundations of the anti-doping movement. Furthermore, the official definition of doping and the structure of the anti-doping agencies are presented.

Noble metal nanostructures in optical biosensors: Basics, and their introduction to anti-doping detection.

Nanotechnology has illustrated significant potentials in biomolecular-sensing applications; particularly its introduction to anti-doping detection is of great importance. Illicit recreational drugs, substances that can be potentially abused, and drugs with dosage limitations according to the prohibited lists announced by the World Antidoping Agency (WADA) are becoming of increasing interest to forensic chemists. In this review, the theoretical principles of optical biosensors based on noble metal nanoparticles, and the transduction mechanism of commonly-applied plasmonic biosensors are covered. We review different classes of recently-developed plasmonic biosensors for analytic determination and quantification of illicit drugs in anti-doping applications. The important classes of illicit drugs include anabolic steroids, opioids, stimulants, and peptide hormones. The main emphasis is on the advantages that noble metal nano-particles bring to optical biosensors for signal enhancement and the development of highly sensitive (label-free) biosensors. In the near future, such optical biosensors may be an invaluable substitute for conventional anti-doping detection methods such as chromatography-based approaches, and may even be commercialized for routine anti-doping tests.

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.

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.