Athlete biological passport: longitudinal biomarkers and statistics in the fight against doping.

As novel substances, short time windows, and limits of detection increasingly challenge direct methods of doping detection in sports, indirect tools inevitably take a greater role in the fight against it. One such tool is the athlete biological passport (ABP) - a longitudinal profiling of the measured haematological and biochemical biomarkers, combined with calculated scores, against the background of epidemiological data crucial for doping detection. In both of its modules, haematological and steroidal, ABP parameters are analysed with the Bayesian adaptive model, which individualises reference and cut-off values to improve its sensitivity. It takes into account the confounding factors with proven and potential influence on the biomarkers, such as race and altitude exposure. The ABP has already changed the fight against doping, but its importance will further grow with the new modules (e.g., endocrinological), parameters (e.g., plasma volume-independent parameters), and complementing indirect methods (e.g., transcriptomic).

Gene Doping Control Analysis of Human Erythropoietin Transgene in Equine Plasma by PCR-Liquid Chromatography High-Resolution Tandem Mass Spectrometry.

Gene doping involves the misuse of genetic materials to alter an athlete's performance, which is banned at all times in both human and equine sports. Quantitative polymerase chain reaction (qPCR) assays have been used to control the misuse of transgenes in equine sports. Our laboratory recently developed and implemented duplex as well as multiplex qPCR assays for transgenes detection. To further advance gene doping control, we have developed for the first time a sensitive and definitive PCR-liquid chromatography high-resolution tandem mass spectrometry (PCR-LC-HRMS/MS) method for transgene detection with an estimated limit of detection of below 100 copies/mL for the human erythropoietin (hEPO) transgene in equine plasma. The method involved magnetic-glass-particle-based extraction of DNA from equine plasma prior to PCR amplification with 2'-deoxyuridine 5'-triphosphate (dUTP) followed by treatments with uracil DNA glycosylase and hot piperidine for selective cleavage to give small oligonucleotide fragments. The resulting DNA fragments were then analyzed by LC-HRMS/MS. The applicability of this method has been demonstrated by the successful detection of hEPO transgene in a blood sample collected from a gelding (castrated male horse) that had been administered the transgene. This novel approach not only serves as a complementary method for transgene detection but also paves the way for developing a generic PCR-LC-HRMS/MS method for the detection of multiple transgenes.

Evidence of ostarine excretion in oral fluid after a single controlled oral administration.

The presence of ostarine, a selective androgen receptor modulator (SARM) in an athlete's urine specimen constitutes one of the most frequent anti-doping rules violation as the drug is listed as a member of the S1.2 class "other anabolic agents" of the World Anti-doping Agency Prohibited List, forbidden in- and out-competition. It is possible to challenge this violation but it is at the charge of the athlete to prove innocence. The conditions to evidence no fault or negligence are mostly based on 2 points: 1. the athlete must present verified circumstances of contamination and the source of contamination must be identified; and 2. there must be verified claims by the athlete that the violation was not intentional. Some months before the Olympic games, a female athlete was suspended by a national anti-doping agency because of an adverse analytical finding for ostarine. She claimed that her violation was due to drug transfer when kissing her boyfriend, who did not inform her about his ostarine daily intake. To document this claim (excretion of ostarine in oral fluid in sufficient amounts), a male volunteer ingested 17.3 mg of ostarine (dose verified by 1H NMR). Oral fluid was collected over 8 h using the NeoSal™ collection device and was tested by liquid chromatography coupled to tandem mass spectrometry. Maximal ostarine concentration was 468 ng/mL at T + 15 min, which can also be partially attributed to mouth contamination. Ostarine was detectable during the whole period of test, with concentrations at 1-2 ng/mL after T + 4 h. These results support drug transfer during kissing and subsequent possible contamination of the partner.

LC-MS/MS measurement of endogenous steroid hormones and phase II metabolites in blood volumetric absorptive microsampling (VAMS) for doping control purposes.

BACKGROUND: Volumetric Absorptive Microsampling (VAMS) is emerging as a valuable technique in the collection of dried biological specimens, offering a potential alternative to traditional sampling methods. The objective of this study was to assess the suitability of 30 µL VAMS for the measurement of endogenous steroid hormones. METHODS: A novel LC-MS/MS method was developed for the quantification of 18 analytes in VAMS samples, including main endogenous free steroids and phase II metabolites of androgens. The method underwent validation in accordance with ISO/IEC 17025:2017 and World Anti-Doping Agency (WADA) requirements. Subsequently, it was applied to authentic VAMS samples obtained from 20 healthy volunteers to assess the stability of target analytes under varying storage conditions. RESULTS: The validation protocol assessed method's selectivity, matrix effect, extraction recovery, quantitative performance, carry-over and robustness. The analysis of authentic samples demonstrated the satisfactory stability of monitored steroids in VAMS stored at room temperature, 4 °C, -20 °C and -80 °C for up to 100 days and subjected to up to 3 freezing-thawing cycles. CONCLUSIONS: The validated LC-MS/MS method demonstrated its suitability for the measurement of steroids in dried blood VAMS. The observed stability of steroidal compounds suggests promising prospects for future applications of VAMS, both in anti-doping contexts and clinical research.

Body fluid contamination in the context of an adverse analytical finding in doping: About a case involving ostarine.

Ostarine, also known as MK-2866 or enobosarm, is a selective androgen receptor modulator (SARM). It has anabolic properties and as such is widely used in doping, accounting in 2021 for 25 % of the adverse analytical findings (AAF) among the class S1.2 "Other anabolic agents" of products banned by the World Anti-Doping Agency, to which it belongs. But in some cases, it can be responsible for an AAF following contamination. We report the case of an athlete who contaminated herself by exchanging body fluids while kissing her boyfriend, who took 25 mg per day of MK-2866 for 9 days prior to the athlete's AAF (urinary concentration evaluated at 13 ng/mL) without her knowledge. Both subjects came to our lab for hair testing. The athlete's hair was black and slightly frizzy. Six segments of 2 cm then 7 × 3 cm (33 cm) were analysed and showed increasing concentrations, from 2 pg/mg on the first segment to 17.8 pg/mg on the last segment. The boyfriend's hair, light-brown, analyzed on 4 × 2 cm, also showed increasing values, from 65 to 143 pg/mg. These gradients of concentration in the hair's athlete and in her boyfriend were compatible with external contamination of the hair, confirmed by analysis of washing baths, pillowcases (150 pg on each), and the athlete's hairbrush (250 pg). Fingernails were also contaminated, with 21 pg/mg in the athlete and 1041 pg/mg in the boyfriend, with highly contaminated washing baths, and toenails were less contaminated, with 2 pg/mg in the athlete and 17.3 pg/mg in the boyfriend. Urine samples taken 35 days after the start of MK-2866 treatment showed a value of 3690 ng/mL in the boyfriend and 5.7 ng/mL in the athlete. After 6 days off, these concentrations were 3.3 ng/mL and 0.1 ng/mL, respectively. A controlled transfer study was carried out 12 days after discontinuation (urine concentrations returned to negative level). After administration of 17 mg (the 25 mg/mL vial having been controlled at 17 mg/mL), urine samples were taken from the boyfriend and the athlete (n = 10 for each) for more than 25 h after they had been living normally with each other (regular kissing in particular). The boyfriend's urine concentrations ranged from 681 ng/mL to 12822 ng/mL (Tmax = 8:30 hrs), and the athlete's from 0.3 ng/mL to 13 ng/mL with Tmax = 8:30 hrs, i.e. at 22:30 hrs, which corresponded exactly to the time of collection of the urine that showed AAF, with a similar concentration. The dose ingested by the athlete was estimated at 15 µg. These results demonstrate the transfer of ostarine via body fluids between two subjects, with a high risk of AAF in one athlete, as observed in our case.

The effects of anti-doping measures on sports performance in weightlifting.

BACKGROUND: Evaluating anti-doping measures is essential to optimise their effectiveness. Comparing sporting results that have a higher doping prevalence, such as weightlifting, before and after the implementation of anti-doping measures may serve as an effectiveness indicator. METHODS: The results of the most successful weightlifters of both sexes in two time periods, 2009-2015 and 2016-2022 were analysed. The Sinclair Total (ST) to compare the relative strength of weightlifters from different weight categories was calculated. RESULTS: A significant decrease in the ST during 2016-2022 (p < 0.001) in athletes of all ages and both sexes overall was reported. When analysed by age, there was a decrease in ST in juniors and seniors of both sexes (p = 0.010 and p < 0.001, respectively), but not in youth. There was a decrease in the ST in senior men (p < 0.001), junior women (p < 0.001) and senior women (p < 0.001). CONCLUSION: In elite weightlifting, adult athletic results declined during 2016-2022, which may partly be explained by the implementation of new methods to detect long-term anabolic androgenic steroid metabolites as well as other policies. This may highlight the effectiveness of these methods both in the prevention and detection of anti-doping rule violations.

Barriers and enablers in doping, anti-doping, and clean sport: A qualitative meta-synthesis informed by the theoretical domains framework and COM-B model.

To protect the integrity of sport, and the health of athletes, global anti-doping programmes seek to prevent doping, and elicit anti-doping and clean sport behaviours, through education, deterrence, detection, enforcement, and rules. To guide programme development, this meta-synthesis of qualitative research applied a behavioural science framework to identify barriers and enablers to doping, anti-doping, and clean sport. A systematic search of electronic databases up to May 2022, followed by critical appraisal, resulted in 73 included articles. Fifty-two articles reported the athlete perspective, thirteen included athletes, athlete support personnel (ASP), and other experts, and eight focused on ASP only. Rigorous methods of thematic synthesis were drawn upon to construct analytical themes in line with the theoretical domains framework (TDF) and the capability, opportunity, and motivation model of behaviour (COM-B). A wide range of barriers and enablers were identified which influenced capability, opportunity, and motivation to participate in a clean sport environment. The weight of evidence pointed to limitations in the current anti-doping education system in providing athletes and ASP with the knowledge and skills to protect against doping, as well as the significant influence of social and cultural norms in shaping doping and clean sport behaviours through a shared social identity, and risky contexts leading to moments of vulnerability to doping. We identified a need for anti-doping programmes to move beyond the current focus on athlete capability, and address the opportunity and motivation components of clean sport behaviours through a targeted and tailored focus on education, training, persuasion, modelling and environmental restructuring interventions.

Pharmacokinetic study of osilodrostat and identification of mono-hydroxylated metabolite in equine plasma for the purpose of doping control.

RATIONALE: Osilodrostat is an inhibitor of 11-beta-hydroxylase (CYP11B) and is used for the treatment of Cushing's disease but also categorized as an anabolic agent. The use of osilodrostat is prohibited in horseracing and equestrian sports. To the best of our knowledge, this is the first metabolic study of osilodrostat in equine plasma. METHODS: Potential metabolites of osilodrostat were identified by differential analysis using data acquired from pre- and post-administration plasma samples after protein precipitation with liquid chromatography electrospray ionization high-resolution mass spectrometry (LC/ESI-HRMS). [Correction added on 27 January 2023, after first online publication: In the preceding sentence, "C-HRMS" was changed to "LC/ESI-HRMS" in this version.] For quantification of osilodrostat, a strong cation exchange solid-phase extraction was employed, and the extracts were analyzed using LC/ESI-triple quadrupole tandem mass spectrometry (LC/ESI-QqQ-MS/MS) to establish its elimination profile. Such extracts were further analyzed using LC/ESI-HRMS to investigate the detectability of osilodrostat and its identified mono-hydroxylated metabolite over a 2-week sampling period. RESULTS: Mono-hydroxylated osilodrostat was identified based on the differential analysis and mass spectrometric interpretations, and it was found to be the most abundant metabolite in plasma. Elimination profile of osilodrostat in plasma was successfully established over the 24-h post-administration period. Both osilodrostat and its mono-hydroxylated metabolite were detected up to the last sampling point at 2 weeks using HRMS, and osilodrostat could be confirmed up to 8-day post-administration with its reference material using HRMS as well. CONCLUSIONS: For doping control, screening of both the parent drug osilodrostat and its mono-hydroxylated metabolite in equine plasma would be recommended due to their extended detection windows of up to 2 weeks. Given the availability of reference material for potential confirmation in forensic samples, osilodrostat is considered the most appropriate monitoring target.

Differences in Consumption Behaviour of Dietary Supplements in Competitive Athletes Depends on Sports Discipline.

BACKGROUND: The consumption of dietary supplements (DS) is widespread among the general population and competitive athletes. However, only a few competitive athletes seek information from experts about the effects and use of DS. Furthermore, it is currently unknown whether certain sports have a higher affinity for DS than others. METHODS: This study aimed to identify differences between different sports categories and subgroups that may have a very high affinity for DS. For this purpose, competitive athletes were surveyed. The survey included the type of sport, the training frequency, the number of competitions, the consumption behaviour of five DS categories (general health, regeneration promotion, performance enhancement, booster, and weight loss) as well as personal data such as biological sex and age. Subsequently, correlations, configural frequencies (CFA), and multiple correspondence analyses (MCA) were used to identify subgroups with a high affinity of consumption behaviour. RESULTS: A total of 409 questionnaires could be evaluated. It was found that all DS categories except weight loss were related. In addition, it was observed that in sports from the power category and from the endurance category, there was even higher consumption behaviour than in other sports categories. Male power athletes in particular have a higher affinity for consuming DS than other subgroups. CONCLUSIONS: This study shows that there is a clear different consumption behaviour depending on the type of sport. Male power athletes in particular are the subgroup with the greatest consumption behaviour and therefore require special education on the effects and use of DS. This subgroup in particular should receive increased attention in counselling on DS to minimise the possible risks of DS use.

Urinary excretion profile of higenamine in females after oral administration of supplements - Doping scenario.

In 2017, higenamine was added to the World Antidoping Agency's (WADA) Prohibited list under group S3: beta-2 agonists and it is banned for athletes both in - and out of competition. Aim of this study was to characterize the urinary excretion profile of higenamine and its metabolite coclaurine after oral administration of multiple doses of higenamine capsules. For this purpose, an administration study including female basketball players was performed. For the detection of higenamine and cocalurine in the collected urine samples, a new, fast, and highly sensitive quantitative on-line SPE LC HRMS method was developed and validated. The method was applied for the quantification of higenamine and cocalurine in urine and their excretion pattern was defined. Results obtained show substantial inter-individual differences in the excretion profile of higenamine and coclaurine. For higenamine, half-lives were estimated to be between 4 and 27 h, and for coclaurine between 5 and 25 h. Furthermore, the data indicate that the elimination of coclaurine is rate-limited by its formation. Higenamine could be detected at a urine concentration above 10 ng/mL for at least 20 h after the last application for all study participants.

Supplement usage and doping attitudes in elite youth sports: The mediating role of dietary supplement acceptance.

This study investigated whether dietary supplement acceptance mediated the relationship between supplement use and doping attitudes in youth sports. To this end, we employed a two-wave half-longitudinal design during a sports season (time point one [T1] to time point two [T2]). The sample consisted of 217 elite youth athletes (47% male; mean age = 16.98 years, standard deviation = 0.88) who competed in team sports (43%; N = 93; basketball, floorball, handball, and ice hockey) and individual sports (57%; N = 124; alpine skiing, biathlon, cross-country skiing, swimming, and tennis). The participants were recruited from eight Norwegian sports academy high schools that provide extracurricular, higher-level training and specialization for youth athletes. Results from structural equation modeling analysis indicated that dietary supplement acceptance (T2) mediated the positive relationship between supplement use (T1) and doping attitudes (T2) when accounting for prior levels of the mediator and the outcome variable. These findings suggest that when young athletes used dietary supplements at the start of the season to improve their performance, they were more likely to view the use of supplements as acceptable and to report more favorable attitudes toward doping at the end of the season six months later. For those seeking to prevent doping in youth sports, targeting athletes' views on the acceptable use of dietary supplements may be important.

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.

Prevalence of Drug Use in Ultraendurance Athletes.

PURPOSE: In competitive sport, classic methods of measuring drug prevalence, such as doping controls or questionnaires, are challenging. Here we describe a novel urine sampling method to measure drug use in athletes. We hypothesize that the prevalence of drug use in ultramarathon runners is measured more accurately with our sampling method than randomized-response questionnaires. METHODS: Urine samples and associated demographic data were collected from male participants using blind, automated urinals at the start of ultramarathon races. Various nonprohibited and prohibited substances were subsequently screened. Concomitantly, 2931 male and female runners participating in the same ultramarathons completed an anonymized, randomized-response questionnaire regarding drug use. RESULTS: Among 412 individual urine samples, 205 (49.8%) contained at least one substance, and 16.3% of the samples contained one or more prohibited substances. Substances detected in urine included nonsteroid anti-inflammatory drugs (NSAID) (22.1%), acetaminophen (15.5%), opioids (6.6%), diuretics (4.9%), hypnotics (4.4%), glucocorticoids (2.7%), beta-2 agonists (2.2%), cannabinoids (1.9%), and stimulants (1.2%). None of the samples contained erythropoietin-receptor agonists or suspicious testosterone. Drug use was not associated with the participants' characteristics or ranking. Respondents to the questionnaire reported using acetaminophen (13.6%) and NSAID (12.9%); however, no prohibited substances were declared. CONCLUSIONS: There was a high prevalence of drug use among male ultramarathon runners, in particular, NSAID and painkillers; however, performance-enhancing drugs were marginally used. Blind urine sampling highlighted prohibited drug use not declared in questionnaires, and it is useful to assess the prevalence of drug use and/or doping in competitive athletes.

Chromatographic-mass spectrometric analysis of peptidic analytes (2-10 kDa) in doping control urine samples.

Peptides with a molecular mass between 2 and 10 kDa that are prohibited in elite sports usually require dedicated sample preparation and mass spectrometric detection that commonly cannot be combined with other (lower molecular mass) substances. In most instances, the physicochemical differences are too significant to allow for a generic analytical procedure. A simplification of established and comparably complex analytical approaches is therefore desirable and has been accomplished in the context of this study. With urine samples representing still the most frequently collected doping control specimens, efficient extraction of peptidic analytes from this matrix was a major goal of this method, as demonstrated for the included compounds such as insulins (human, lispro, aspart, glulisine, tresiba, glargine metabolite, bovine insulin, porcine insulin), growth hormone-releasing hormones (sermorelin, CJC-1295, tesamorelin) incl. their respective metabolites, insulin-like-growth factors (long-R3 -IGF-I, R3 -IGF-I, des1-3 -IGF-I), synacthen, gonadorelin and mechano growth factors (human MGF, MGF-Goldspink). Sample preparation and detection are controlled by five internal standards, covering all five included peptide drug categories. Nearly all requirements of the recent technical documents from the World Anti-Doping Agency (WADA) considering their minimum required performance levels (MRPL) are fulfilled, and the method was validated for its utilisation as initial testing procedure in doping controls. Finally, the approach was applied to authentic post-administration study urine samples (for insulins and gonadorelin) in order to provide proof of principle.

Application of a bar adsorptive microextraction based methodology for doping control of alkylamine stimulants in urine matrices.

To comply with 'World Anti-Doping Agency' (WADA) guidelines, doping control laboratories must continuously adjust their analytical procedures. Therefore, sample preparation continues to play a critical step in modern analytical strategies, namely by replacing the tedious, time and solvent consuming commonly employed (e.g. liquid-liquid extraction). The present contribution proposes, for the first time in doping control, bar adsorptive microextraction (BAµE) as an alternative analytical technique for the qualitative determination of six alkyl amine stimulants (AAs; 1,3-dimethylbutylamine, 1,4-dimethylpentylamine, heptaminol, isometheptene, octodrine and tuaminoheptane) in urine matrices followed by derivatization prior to gas chromatography coupled to mass spectrometry, operating in the selected ion monitoring mode acquisition (GC-MS(SIM)). After selecting the most selective coating phase, i.e., a mixed-mode reversed phase/strong anion exchange sorbent (P2), assays performed under optimized experimental conditions [microextraction - BAµE(P2), 1 h (1,000 rpm), pH 11, 10 % NaCl; back-extraction - methanol (150 µL), 30 min, under sonication], allowed remarkable recoveries ranging from 48.7 % (heptaminol, 200 ng/mL) to 83.1 % (1,4-dimethylpentylamine, 200 ng/mL). The validation assessment assays of the proposed methodology showed suitable limits of identification (5.0-35.0 ng/mL), appropriate linear dynamic ranges (5.0-200.0 ng/mL) and good determination coefficients (r2 > 0.9937), as well as excellent selectivity, robustness, accuracy and precision. To check whether the methodology is fit-for-purpose, four previously analysed proficiency urine samples were successfully tested, in which were unequivocally detected and identified some of the target AAs. The present methodology showed to be a remarkable alternative in comparison to other dedicated analytical approaches to screen AAs in urine matrices, since it is cost-effective, user- and eco-friendly, requiring low volume of urine sample (1 mL). The great potential of this analytical technology in doping control lies in a very effective microextraction combined with the minimization of potential interferents, presenting itself as an added value to be applied to other types of substances and complex matrices.

A new enigma: doping in E-sports.

Electronic sports (e-sports) is a growing entity that is estimated to be valued at USD $200 billion by the end of 2023. With the rapid rate of growth, it will come to a point that e-sports will need to be regulated including regulatory mechanisms of fair play, which includes sports doping. With the emergence of substances that provides unfair advantages in terms of concentration, staying awake and preventing anxiety including tremors, there is a need to regulate doping in e-sports. However, due to the nature of the sport, it might not be as straightforward to regulate as other sports.

Recent advances in mass spectrometry for the detection of doping.

INTRODUCTION: The analysis of doping control samples is preferably performed by mass spectrometry, because obtained results meet the highest analytical standards and ensure an impressive degree of reliability. The advancement in mass spectrometry and all its associated technologies thus allow for continuous improvements in doping control analysis. AREAS COVERED: Modern mass spectrometric systems have reached a status of increased sensitivity, robustness, and specificity within the last decade. The improved sensitivity in particular has, on the other hand, also led to the detection of drug residues that were attributable to scenarios where the prohibited substances were not administered consciously but rather by the unconscious ingestion of or exposure to contaminated products. These scenarios and their doubtless clarification represent a great challenge. Here, too, modern MS systems and their applications can provide good insights in the interpretation of dose-related metabolism of prohibited substances. In addition to the development of new instruments itself, software-assisted analysis of the sometimes highly complex data is playing an increasingly important role and facilitating the work of doping control laboratories. EXPERT OPINION: The sensitive analysis and evaluation of a higher number of samples in a shorter time is made possible by the ongoing developments in mass spectrometry.

The presence of doping agents in dietary supplements: A glimpse into the Brazilian situation.

Dietary supplements (DS) are intended for healthy people to maintain or improve their overall health. Its consumption is widespread in large part of the general population and at all levels of athletes. Nevertheless, DS use can also pose health risks to individuals and, in the case of athletes, may lead to adverse analytical findings (AAFs) due to the possibility of DS contamination or adulteration with doping agents banned by the World Anti-Doping Agency. Although educational initiatives are being performed in Brazil to warn the sports community about inadvertent doping cases, AAFs connected to the DS administration have been increasingly growing. The findings of DS analyzed by the Brazilian Doping Control Laboratory (LBCD), between 2017 and 2022, after Testing Authorities (TAs) analysis requests, showed an alarming number of tainted samples. Diuretics were the most common adulterants found in all supplement types. However, the profile of prohibited substances in manufactured and compounded dietary supplements (MDS and CDS, respectively) were distinct, with stimulants being most prevalent in MDS and anabolic agents in CDS products. Additionally, MDS samples generally presented higher estimated concentrations of banned substances (mg/g) than CDS samples (µg/g). The common practice of DS intake by athletes continues to be of great concern for a doping-free sport, given the high prevalence of prohibited substances detected in the analyzed samples by the LBCD. The current Brazilian scenario reinforces the importance of raising awareness in the sports community of the possible consequences of an unintentional doping case linked to DS use.

Indirect biomarkers of blood doping: A systematic review.

The detection of blood doping represents a current major issue in sports and an ongoing challenge for antidoping research. Initially focusing on direct detection methods to identify a banned substance or its metabolites, the antidoping effort has been progressively complemented by indirect approaches. The longitudinal and individual monitoring of specific biomarkers aims to identify nonphysiological variations that may be related to doping practices. From this perspective, the identification of markers sensitive to erythropoiesis alteration is key in the screening of blood doping. The current Athlete Biological Passport implemented since 2009 is composed of 14 variables (including two primary markers, i.e., hemoglobin concentration and OFF score) for the hematological module to be used for indirect detection of blood doping. Nevertheless, research has continually proposed and investigated new markers sensitive to an alteration of the erythropoietic cascade and specific to blood doping. If multiple early markers have been identified (at the transcriptomic level) or developed directly in a diagnostics' kit (at a proteomic level), other target variables at the end of the erythropoietic process (linked with the red blood cell functions) may strengthen the hematological module in the future. Therefore, this review aims to provide a global systematic overview of the biomarkers considered to date in the indirect investigation of blood doping.

Asthma and exercise-induced bronchoconstriction in athletes: Diagnosis, treatment, and anti-doping challenges.

Athletes often experience lower airway dysfunction, such as asthma and exercise-induced bronchoconstriction (EIB), which affects more than half the athletes in some sports, not least in endurance sports. Symptoms include coughing, wheezing, and breathlessness, alongside airway narrowing, hyperresponsiveness, and inflammation. Early diagnosis and management are essential. Not only because untreated or poorly managed asthma and EIB potentially affects competition performance and training, but also because untreated airway inflammation can result in airway epithelial damage, remodeling, and fibrosis. Asthma and EIB do not hinder performance, as advancements in treatment strategies have made it possible for affected athletes to compete at the highest level. However, practitioners and athletes must ensure that the treatment complies with general guidelines and anti-doping regulations to prevent the risk of a doping sanction because of inadvertently exceeding specified dosing limits. In this review, we describe considerations and challenges in diagnosing and managing athletes with asthma and EIB. We also discuss challenges facing athletes with asthma and EIB, while also being subject to anti-doping regulations.