Search

Background: Anabolic androgenic steroids (AAS) are thought to increase venous thromboembolism (VTE) risk., Objectives: We investigated whether AAS influence coagulation parameters associated with VTE by assessing their changes during and after AAS use., Methods: The HAARLEM study enrolled 100 male amateur athletes voluntarily starting an AAS cycle between 2015 and 2018. We measured procoagulant and anticoagulant protein levels, D-dimer levels, endogenous thrombin potential (ETP), and clot lysis time (CLT) at baseline and during 2 years of follow-up. Changes in coagulation during AAS cycle, 3 months after its discontinuation, and 1 year after its inclusion compared with baseline were estimated using linear mixed models. The associations between AAS dose and duration of use with these outcomes were studied through adjusted multivariable linear regression., Results: Participants used AAS for a median of 13 weeks (IQR: 10-23) with a median weekly dose of 901 mg (IQR: 634-1345 mg). Mean levels of multiple coagulation factors (F) increased during use compared with baseline, whereas FVIII and von Willebrand factor levels remained unchanged. Protein S and D-dimer showed the biggest increase (22% [95% CI: 15-29] and 1.3-fold [95% CI: 1.2-1.5], respectively). CLT was 8 minutes longer (95% CI: 5-10) and ETP was 165 nM∗min (95% CI: -205 to -124) lower during the AAS cycle. A high weekly AAS dose and short cycle duration were associated with changes in protein S and ETP during use. All parameters returned to baseline values 3 months after discontinuation and remained similar after., Conclusion: During AAS use, procoagulant and anticoagulant protein levels increased in a reversible manner. The overall balance did not suggest a clear procoagulant state., (© 2023 Published by Elsevier Inc. on behalf of International Society on Thrombosis and Haemostasis.)

Background: High levels of admitted doping use (43.6% and 57.1%) were reported for two international sport events in 2011. Because these are frequently referenced in evaluating aspects of anti-doping, having high level of confidence in these estimates is paramount., Objectives: In this study, we present new prevalence estimates from a concurrently administered method, the Single Sample Count (SSC), and critically review the two sets of estimates in the context of other doping prevalence estimates., Methods: The survey featuring the SSC model was completed by 1,203 athletes at the 2011 World Championships in Athletics (WCA) (65.3% of all participating athletes) and 954 athletes at the 2011 Pan-Arab Games (PAG) (28.2% of all participating athletes). At WCA, athletes completed both UQM and SSC surveys in randomised order. At PAG, athletes were randomly allocated to one of the two surveys. Doping was defined as "having knowingly violated anti-doping regulations by using a prohibited substance or method.", Results: Estimates with the SSC model for 12-month doping prevalence were 21.2% (95% CI: 9.69-32.7) at WCA and 10.6% (95% CI: 1.76-19.4) at PAG. Estimated herbal, mineral, and/or vitamin supplements use was 8.57% (95% CI: 1.3-16.11) at PAG. Reliability of the estimates were confirmed with re-sampling method ( n = 1,000, 80% of the sample). Survey non-compliance (31.90%, 95%CI: 26.28-37.52; p < 0.0001) was detected in the WCA data but occurred to a lesser degree at PAG (9.85%, 95% CI: 4.01-15.69, p = 0.0144 and 11.43%, 95% CI: 5.31-11.55, p = 0.0196, for doping and nutritional supplement use, respectively). A large discrepancy between those previously reported from the UQM and the prevalence rate estimated by the SSC model for the same population is evident., Conclusion: Caution in interpreting these estimates as bona fide prevalence rates is warranted. Critical appraisal of the obtained prevalence rates and triangulation with other sources are recommended over "the higher rate must be closer to the truth" heuristics. Non-compliance appears to be the Achilles heel of the indirect estimation models thus it should be routinely tested for and minimised. Further research into cognitive and behaviour aspects, including motivation for honesty, is needed to improve the ecological validity of the estimated prevalence rates., Competing Interests: AP was a member of the first WADA Working Group on Doping Prevalence between 2011 and 2012 and she chairs the current WADA Working Group on Doping Prevalence since 2017. OH, MS, and DS are members the current WADA Working Group on Doping Prevalence since 2017. MC is an ad hoc member of the WADA Working Group on Doping Prevalence. Working Group members receive no salary for their work for WADA but are entitled to expenses covered and to receive indemnity for formal meetings and up to five days per year for preparation., (Copyright © 2022 Petróczi, Cruyff, de Hon, Sagoe and Saugy.)

Androgen abuse is associated with unfavourable changes in blood pressure, lipid metabolism and erythrocytosis. Most knowledge is based on cross-sectional studies sensitive to bias. We assessed the magnitude of these effects and their recovery in a prospective cohort study which included 100 men (≥18 years) performing an androgen cycle. Clinic visits took place before the cycle, at the end, 3 months after and 1 year after start of the cycle and included measurement of blood pressure, lipid parameters and haematocrit. During androgen use, systolic and diastolic blood pressure increased 6.87 (95% CI 4.34-9.40) and 3.17 mmHg (1.29-5.04) compared to baseline respectively. LDL cholesterol and ApoB increased 0.45 mmol/L (0.29-0.61) and 18.2 mg/dl (13.5-22.8) respectively, whereas HDL cholesterol, ApoA and Lp(a) decreased with 0.40 mmol/L (-0.45 to 0.35), 36.6 mg/dl (30.2-42.9) and 37.6% (13.9-61.3). ANGPTL3 increased 20.3% (7.38-33.2). Mean haematocrit increased 0.03 L/L (0.02-0.03). Three months after the cycle, and 1 year after the start, these parameters returned to baseline. In conclusion, androgen abuse induces small but clinically relevant adverse changes in blood pressure, lipid metabolism and erythrocytosis which are rapidly reversible after cessation. As follow-up was limited to 1 year, the impact of androgen abuse on cardiovascular disease remains uncertain., (© 2022 Wiley-VCH GmbH.)

Background: The prevalence of doping in competitive sport, and the methods for assessing prevalence, remain poorly understood. This reduces the ability of researchers, governments, and sporting organizations to determine the extent of doping behavior and the impacts of anti-doping strategies., Objectives: The primary aim of this subject-wide systematic review was to collate and synthesize evidence on doping prevalence from published scientific papers. Secondary aims involved reviewing the reporting accuracy and data quality as evidence for doping behavior to (1) develop quality and bias assessment criteria to facilitate future systematic reviews; and (2) establish recommendations for reporting future research on doping behavior in competitive sports to facilitate better meta-analyses of doping behavior., Methods: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used to identify relevant studies. Articles were included if they contained information on doping prevalence of any kind in competitive sport, regardless of the methodology and without time limit. Through an iterative process, we simultaneously developed a set of assessment criteria; and used these to assess the studies for data quality on doping prevalence, potential bias and reporting., Results: One-hundred and five studies, published between 1975 and 2019,were included. Doping prevalence rates in competitive sport ranged from 0 to 73% for doping behavior with most falling under 5%. To determine prevalence, 89 studies used self-reported survey data (SRP) and 17 used sample analysis data (SAP) to produce evidence for doping prevalence (one study used both SRP and SAP). In total, studies reporting athletes totaled 102,515 participants, (72.8% men and 27.2% women). Studies surveyed athletes in 35 countries with 26 involving athletes in the United States, while 12 studies examined an international population. Studies also surveyed athletes from most international sport federations and major professional sports and examined international, national, and sub-elite level athletes, including youth, masters, amateur, club, and university level athletes. However, inconsistencies in data reporting prevented meta-analysis for sport, gender, region, or competition level. Qualitative syntheses were possible and provided for study type, gender, and geographical region. The quality assessment of prevalence evidence in the studies identified 20 as "High", 60 as "Moderate", and 25 as "Low." Of the 89 studies using SRP, 17 rated as "High", 52 rated as "Moderate", and 20 rated as "Low." Of the 17 studies using SAP, 3 rated as "High", 9 rated as "Moderate", and 5 rated as "Low." Examining ratings by year suggests that both the quality and quantity of the evidence for doping prevalence in published studies are increasing., Conclusions: Current knowledge about doping prevalence in competitive sport relies upon weak and disparate evidence. To address this, we offer a comprehensive set of assessment criteria for studies examining doping behavior data as evidence for doping prevalence. To facilitate future evidence syntheses and meta-analyses, we also put forward "best practice" recommendations and reporting guidelines that will improve evidence quality., (© 2021. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Tools for reliable assessment of socially sensitive or transgressive behavior warrant constant development. Among them, the Crosswise Model (CM) has gained considerable attention. We systematically reviewed and meta-analyzed empirical applications of CM and addressed a gap for quality assessment of indirect estimation models. Guided by the PRISMA protocol, we identified 45 empirical studies from electronic database and reference searches. Thirty of these were comparative validation studies (CVS) comparing CM and direct question (DQ) estimates. Six prevalence studies exclusively used CM. One was a qualitative study. Behavior investigated were substance use and misuse ( k = 13), academic misconduct ( k = 8), and corruption, tax evasion, and theft ( k = 7) among others. Majority of studies ( k = 39) applied the "more is better" hypothesis. Thirty-five studies relied on birthday distribution and 22 of these used P = 0.25 for the non-sensitive item. Overall, 11 studies were assessed as high-, 31 as moderate-, and two as low quality (excluding the qualitative study). The effect of non-compliance was assessed in eight studies. From mixed CVS results, the meta-analysis indicates that CM outperforms DQ on the "more is better" validation criterion, and increasingly so with higher behavior sensitivity. However, little difference was observed between DQ and CM estimates for items with DQ prevalence estimate around 50%. Based on empirical evidence available to date, our study provides support for the superiority of CM to DQ in assessing sensitive/transgressive behavior. Despite some limitations, CM is a valuable and promising tool for population level investigation., Competing Interests: DS, MS, OH, and AP are members, and MC and PH are associated members of the World Anti-Doping Agency's Working Group on Doping Prevalence. They prepared the review in this capacity with support from OS and RC. Members of the Working Group receive no payment for their work but expenses directly related to the Working Group are covered by WADA. WADA has no influence over the content of this paper., (Copyright © 2021 Sagoe, Cruyff, Spendiff, Chegeni, de Hon, Saugy, van der Heijden and Petróczi.)

An estimated 4-6% of fitness center visitors uses anabolic-androgenic steroids (AAS). Reliable data about adverse reactions of AAS are scarce. The HAARLEM study aimed to provide insight into the positive and negative effects of AAS use. One hundred men (≥18 years) who intended to start an AAS cycle on short notice were included for follow-up. Clinic visits took place before (T 0 ), at the end (T 1 ), and three months after the end of the AAS cycle (T 2 ), and one year after the start of the cycle (T 3 ), and comprised a medical history, physical examination, laboratory analysis, and psychological questionnaires. During the follow-up period, four subjects reported a serious adverse event, that is, congestive heart failure, acute pancreatitis, suicidal ideation, and exacerbation of ulcerative colitis. All subjects reported positive side effects during AAS use, mainly increased strength (100%), and every subject reported at least one negative health effect. Most common were fluid retention (56%) and agitation (36%) during the cycle, and decreased libido (58%) after the cycle. Acne and gynecomastia were observed in 28% and 19%. Mean alanine transaminase (ALT) and creatinine increased 18.7 U/l and 4.7 µmol/L, respectively. AAS dose and cycle duration were not associated with the type and severity of side effects. After one-year follow-up (T 3 ), the prevalence of observed effects had returned to baseline. There was no significant change in total scores of questionnaires investigating wellbeing, quality of life, and depression. In conclusion, all subjects experienced positive effects during AAS use. Four subjects experienced a serious adverse event. Other side effects were mostly anticipated, mild, and transient., (© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

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.

Background: The use of anabolic androgenic steroids (AAS) is common among visitors of fitness centers. Knowledge about health risks of AAS use is limited due to lack of clinical studies., Methods: One hundred men, at least 18 years old, intending to start a cycle of AAS were recruited. Baseline demographical data and reasons for AAS use were recorded. Subjects provided samples of AAS for analysis with UPLC-QTOF-MS/MS., Results: One hundred and eleven men were seen for a baseline visit. Nineteen percent had competed in bodybuilding competitions. Recent illicit drug use was reported by 56%. Seventy-seven percent of participants had used AAS in the past, and 97% of them had experienced side effects. After exclusion, 100 men comprised the cohort for follow-up. The AAS cycle performed had a median duration of 13 weeks (range 2-52), and the average dose of AAS equivalents was 901 mg per week (range 250-3.382). Subjects used other performance and image-enhancing drugs (PIEDs) such as growth hormone (21%). In total, 272 AAS samples were analyzed and 47% contained the AAS indicated on the label. The principal reason for AAS use was gain of muscle mass (44%). Forty-eight percent self-reported to being addicted to AAS., Conclusion: The HAARLEM study cohort shows that strength athletes use AAS in a wide variety of cycles and often also use illicit drugs and other potentially harmful PIEDs. The quality of the AAS used is strikingly low. Follow-up of the cohort will provide novel data regarding health risks of AAS use., (© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Recombinant human erythropoietin (rHuEPO) is used as doping a substance. Anti-doping efforts include urine and blood testing and monitoring the athlete biological passport (ABP). As data on the performance of these methods are incomplete, this study aimed to evaluate the performance of two common urine assays and the ABP. In a randomized, double-blinded, placebo-controlled trial, 48 trained cyclists received a mean dose of 6000 IU rHuEPO (epoetin β) or placebo by weekly injection for eight weeks. Seven timed urine and blood samples were collected per subject. Urine samples were analyzed by sarcosyl-PAGE and isoelectric focusing methods in the accredited DoCoLab in Ghent. A selection of samples, including any with false presumptive findings, underwent a second sarcosyl-PAGE confirmation analysis. Hematological parameters were used to construct a module similar to the ABP and analyzed by two evaluators from an Athlete Passport Management Unit. Sensitivity of the sarcosyl-PAGE and isoelectric focusing assays for the detection of erythropoietin abuse were 63.8% and 58.6%, respectively, with a false presumptive finding rate of 4.3% and 6%. None of the false presumptive findings tested positive in the confirmation analysis. Sensitivity was highest between 2 and 6 days after dosing, and dropped rapidly outside this window. Sensitivity of the ABP was 91.3%. Specificity of the urine assays was high; however, the detection window of rHuEPO was narrow, leading to questionable sensitivity. The ABP, integrating longitudinal data, is more sensitive, but there are still subjects that evade detection. Combining these methods might improve performance, but will not resolve all observed shortcomings., (© 2019 The Authors Drug Testing and Analysis Published by John Wiley & Sons Ltd.)

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.

The present study investigates the applicability of the chemical analysis of wastewater to assess the use of doping substances by the general population and amateur athletes. To this end, an analytical methodology that can identify and quantify a list of 15 substances from the groups of anabolic steroids, weight loss products, and masking agents in wastewater has been developed. The method uses solid phase extraction to increase the detection sensitivity of the target analytes, expected to be present at very low concentrations (ng L -1 range), and decrease possible matrix interferences. Instrumental analysis is performed by liquid chromatography coupled to high-resolution mass spectrometry, allowing data acquisition in both full scan and tandem MS mode. The method has been successfully validated at two concentration levels (50 and 200 ng L -1 ) with limits of quantification ranging between 0.7 and 60 ng L -1 , intra- and inter-day precision expressed as relative standard deviation below 15%, procedural recoveries between 60 and 160% and matrix effects ranging from 45 to 121%. The stability of the analytes in wastewater was evaluated at different storage temperatures illustrating the importance of freezing the samples immediately after collection. The application of the method to 24-h composite wastewater samples collected at the entrance of three wastewater treatment plants and one pumping station while different sport events were taking place revealed the presence in wastewater, and hence the use, of the weight loss substances ephedrine, norephedrine, methylhexanamine, and 2,4-dinitrophenol. The use of these stimulants was visible just prior and during the event days and in greater amounts than anabolic steroids or masking agents. Graphical abstract Chemical analysis of untreated wastewater reveals the use of prohibited doping substances during amateur sport event.

Background: The sanction that an athlete receives when an anti-doping rule violation has been committed depends on the specific circumstances of the case. Anti-doping tribunals decide on the final sanction, following the rules of the World Anti-Doping Code., Objectives: To assess the athletes' degree of fault based on the length of sanctions imposed on them to feed policy-related discussions., Methods: Analysing data from the results management database of the World Anti-Doping Agency for anonymous information of anti-doping rule violations in eight selected sports covering the years 2010-2012., Results: Four out of ten athletes who committed an anti-doping rule violation received a suspension that was lower than the standard. This is an indication that tribunals in many instances are not convinced that the athletes concerned were completely at fault, that mitigating circumstances were applicable, or that full responsibility of the suspected violation should not be held against them. Anabolic agents, peptide hormones, and hormone modulators lead to higher sanctions, as do combinations of several anti-doping rule violations., Conclusions: This first analysis of information from the World Anti-Doping Agency's results management database indicates that a large proportion of the athletes who commit anti-doping rule violations may have done this unintentionally. Anti-doping professionals should strive to improve this situation in various ways.

Background: Substances that potentially enhance performance (eg, recombinant human erythropoietin [rHuEPO]) are considered doping and are therefore forbidden in sports; however, the scientific evidence behind doping is frequently weak. We aimed to determine the effects of rHuEPO treatment in well trained cyclists on maximal, submaximal, and race performance and on safety, and to present a model clinical study for doping research on other substances., Methods: We did this double-blind, randomised, placebo-controlled trial at the Centre for Human Drug Research in Leiden (Netherlands). We enrolled healthy, well trained but non-professional male cyclists aged 18-50 years and randomly allocated (1:1) them to receive abdominal subcutaneous injections of rHuEPO (epoetin β; mean dose 6000 IU per week) or placebo (0·9% NaCl) for 8 weeks. Randomisation was stratified by age groups (18-34 years and 35-50 years), with a code generated by a statistician who was not masked to the study. The primary outcome was exercise performance, measured as maximal power output (Pmax), maximal oxygen consumption VO 2 max, and gross efficiency in maximal exercise tests with 25 W increments per 5 min, as lactate threshold and ventilatory threshold 1 (VT1) and 2 (VT2) at submaximal levels during the maximal exercise test, and as mean power, VO 2 , and heart rate in the submaximal exercise tests at the highest mean power output for 45 min in a laboratory setting and in a race to the Mont Ventoux (France) summit, using intention-to-treat analyses. The trial is registered with the Dutch Trial Registry (Nederlands Trial Register), number NTR5643., Findings: Between March 7, 2016, and April 13, 2016, we randomly assigned 48 participants to the rHuEPO group (n=24) or the placebo group (n=24). Mean haemoglobin concentration (9·6 mmol/L vs 9·0 mmol/L [estimated difference 0·6, 95% CI 0·4 to 0·8]) and maximal power output (351·55 W vs 341·23 W [10·32, 3·47 to 17·17]), and VO 2 max (60·121 mL/min per kg vs 57·415 mL/min per kg [2·707, 0·911 to 4·503]) in a maximal exercise test were higher in the rHuEPO group compared with the placebo group. Submaximal exercise test parameters mean power output (283·18 W vs 277·28 W [5·90, -0·87 to 12·67]) and VO 2 (50·288 mL/min per kg vs 49·642 mL/min per kg [0·646, -1·307 to 2·600]) at day 46, and Mont Ventoux race times (1 h 40 min 32 s vs 1 h 40 min 15 s [0·3%, -8·3 to 9·6]) did not differ between groups. All adverse events were grade 1-2 and were similar between both groups. No events of grade 3 or worse were observed., Interpretation: Although rHuEPO treatment improved a laboratory test of maximal exercise, the more clinically relevant submaximal exercise test performance and road race performance were not affected. This study shows that clinical studies with doping substances can be done adequately and safely and are relevant in determining effects of alleged performance-enhancing drugs., Funding: Centre for Human Drug Research, Leiden., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The prevalence of doping in elite sports is relevant for all those involved in sports, particularly for evaluating anti-doping policy measures. Remarkably, few scientific articles have addressed this subject so far, and the last review dates back to 1997. As a consequence, the true prevalence of doping in elite sports is unknown. Even though it is virtually impossible to uncover the exact prevalence of a prohibited activity such as doping, various methods are available to uncover parts of this particular problem, which enables the circumvention (to a certain degree) of the issues of truthfulness, definition problems and the limits of pharmacological evidence. This review outlines the various methods that exist and presents the scarce data available in this area. It is concluded that a combination of questionnaires using the Randomised Response Technique and models of biological parameters is able to provide the statistical possibilities to reveal accurate estimates of this often undisclosed practice. Data gathered in this way yield an estimation of 14-39% of current adult elite athletes who intentionally used doping. These period prevalences have been found in specific sub-groups of elite athletes, and the available data suggest that the prevalence of doping is considerably different between sub-groups with varying types of sport, levels and nationalities. The above-mentioned figure of 14-39% is likely to be a more accurate reflection of the prevalence of intentional doping in elite sports than that provided by doping control test results (estimate of doping: 1-2% annually) or questionnaire-based research (estimations between 1 and 70% depending on sport, level and exact definitions of intent and doping). In the future, analytical science may play a more important role in this topic if it may become feasible to detect very low concentrations of prohibited substances in sewage systems downstream of major sporting events. However, it is clear that current doping control test results show a distinct underestimation of true doping prevalence. It does not seem feasible to distil better estimates of the prevalence of doping based on performance indicators or ego documents because of the various existing effects that influence athletic performance. Such information can only be used as extra information to augment the accuracy of prevalence rates that have been found by using other techniques. True doping prevalence studies have been scarce in elite sports so far. With the correct application of the available scientific methods, preferably using harmonised definitions of the terms 'doping' and 'elite sports', more information on this topic may be gathered in a relatively short time. This would assist anti-doping professionals in the future in order to evaluate the effects of possible anti-doping measures, and better anti-doping policies would serve athletes who compete without doping. The existing anti-doping measures seriously impact the lives of elite athletes and their immediate entourage, which imposes a moral burden to evaluate these measures in the best possible way.

Studies on the use of performance enhancing drugs (PED) in fitness centres rely predominately on conventional survey methods using direct questioning. However, research indicates that direct questioning of sensitive information is characterized by under-reporting. The aim of the present study was to contrast direct questioning of different types of PED use by Dutch fitness centre members with results obtained with the Randomized Response Technique (RRT). Questionnaires were conducted among members of fitness centres. PED were classified into the following categories: anabolic steroids, prohormones, substances to counteract side-effects, growth hormone and/or insulin, stimulants (to reduce weight), and miscellaneous substances. A total of 718 athletes from 92 fitness centres completed the questionnaire. The conventional method resulted in prevalences varying between 0% and 0.4% for the different types of PED with an overall prevalence of 0.4%. RRT resulted in prevalences varying between 0.8% and 4.8% for the different types of PED with an overall prevalence of 8.2%. The overall prevalence of the two survey methods differed significantly. The current study showed that the conventional survey method using direct questioning led to an underestimation of the prevalence. Based on the RRT results, the percentage of users of PED among members of fitness centres is approximately 8.2%. Stimulants to lose weight had the highest prevalence, even higher than anabolic steroids. The key task for future preventive health work is to not only focus on anabolic steroid use, but also include interventions focusing on the use of stimulants to lose weight., (Copyright © 2013 John Wiley & Sons, Ltd.)

Background: To improve anti-doping efforts in sports, the World Anti-Doping Agency (WADA) introduced the World Anti-Doping Program, in which (among others) regulations for providing athletes' whereabouts are described. Because the effectiveness and efficiency of this system depends on the co-operation and compliance of athletes, the perspective of elite athletes is important. This paper answers the following research questions: What is the perspective of Dutch elite athletes on the current whereabouts system in general and how important is their privacy in providing whereabouts in particular? In addition, this study explores how far the whereabouts system can be developed in the future. Are athletes willing to accept greater invasions of their privacy in order to reduce administrative effort and whereabouts failures?, Method: A structured questionnaire was completed by 129 Dutch elite athletes registered in the national and/or international testing pool., Results: The results of this study indicate widespread dissatisfaction with the whereabouts system. Most respondents support anti-doping testing in general, but many athletes feel that WADA's whereabouts system is unacceptable in several respects. In terms of physical privacy, there was a great dissatisfaction. Nearly half of the athletes felt that the '1-hour time slot' limits their freedom, but on the other hand, most athletes disagreed with the statement that the distinction between their sport and private life is disturbed. For almost one in three respondents, the whereabouts system has a negative influence on the pleasure they experience in being an elite athlete. In terms of informational privacy, almost all athletes had confidence in the confidential treatment of their whereabouts information. Almost all athletes would accept giving their phone number to Doping Control Officials, but only half of the athletes would accept sharing their location on their mobile phone. Furthermore, almost two in ten of the athletes would accept wearing a permanent wrist or ankle bracelet or accept being implanted with a GPS chip in order to facilitate future anti-doping testing., Conclusion: The current whereabouts system needs to be improved in order to increase athletes' satisfaction with the anti-doping rules. The athletes themselves need to be engaged in this process. The results of this study indicate that a majority of the athletes are not likely to accept a greater violation of their privacy than the current whereabouts regulations already entail., (Copyright © 2013 Elsevier B.V. All rights reserved.)

The possibility of gene doping, defined as the transfer of nucleic acid sequences and/or the use of normal or genetically modified cells to enhance sport performance, is a real concern in sports medicine. The abuse of knowledge and techniques gained in the area of gene therapy is a form of doping, and is prohibited for competitive athletes. As yet there is no conclusive evidence that that gene doping has been practiced in sport. However, given that gene therapy techniques improve continuously, the likelihood of abuse will increase. A literature search was conducted to identify the most relevant proteins based on their current gene doping potential using articles from Pubmed, Scopus and Embase published between 2006 and 2011. The final list of selected proteins were erythropoietin, insulin-like growth factor, growth hormone, myostatin, vascular endothelial growth factor, fibroblast growth factor, endorphin and enkephalin, α actinin 3, peroxisome proliferator-activated receptor-delta (PPARδ) and cytosolic phosphoenolpyruvate carboxykinase (PEPCK-C). We discuss these proteins with respect to their potential benefits, existing gene therapy experience in humans, potential risks, and chances of detection in current and future anti-doping controls. We have identified PPARδ and PEPCK-C as having high potential for abuse. But we expect that for efficiency reasons, there will be a preference for inserting gene target combinations rather than single gene doping products. This will also further complicate detection.

Physicians should possess specific diagnostic and pharmacotherapeutic skills in order to recognize symptoms associated with doping use. It is important to be on the alert in athletes and fitness enthusiasts for physical and psychological changes due to use of anabolic steroids such as acne, stretch marks, gynecomastia, signs of acromegaly, irascibility and lethargy. Stimulants such as amphetamines, ephedrine and cocaine lead to fat loss and increased alertness; their main side effects are cardiac problems, behavioural changes and addiction. In addition to anabolic steroids and stimulants, erythropoietin, growth hormone, diuretics and glucocorticoids are regularly used to improve sport performance. In cycling, a biological passport will be used in an attempt to detect doping use. In future, the Olympic motto 'citius, altius, fortius' (faster, higher, stronger) will have ground-breaking consequences for the performance and health of top athletes.

Inhaled β₂-agonists are commonly used as bronchodilators in the treatment of asthma. Their use in athletes, however, is restricted by anti-doping regulations. Controversies remain as to whether healthy elite athletes who use bronchodilators may gain a competitive advantage. The aim of this systematic review and meta-analysis is to assess the effects of inhaled and systemic β₂-agonists on physical performance in healthy, non-asthmatic subjects. To this end, MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched up to August 2009. Reference lists were searched for additional relevant studies. The search criteria were for randomized controlled trials examining the effect of inhaled or systemic β₂-agonists on physical performance in healthy, non-asthmatic subjects. Two authors independently performed the selection of studies, data extraction and risk of bias assessment. Parallel-group and crossover trials were analysed separately. Mean difference (MD) and 95% confidence intervals were calculated for continuous data and, where possible, data were pooled using a fixed effects model. Twenty-six studies involving 403 participants (age range 7-30 years) compared inhaled β₂-agonists with placebo. No significant effect could be detected for inhaled β₂-agonists on maximal oxygen consumption (VO₂(max)) [MD -0.14 mL · kg⁻¹ · min⁻¹; 95% CI -1.07, 0.78; 16 studies], endurance time to exhaustion at 105-110% VO₂(max) (MD -1.5 s; 95% CI -15.6, 12.6; four studies), 20-km time trial duration (MD -4.4 s; 95% CI -23.5, 14.7; two studies), peak power (MD -0.14 W · kg⁻¹; 95% CI -0.54, 0.27; four studies) and total work during a 30-second Wingate test (MD 0.80 J · kg⁻¹; 95% CI -2.44, 4.05; five studies). Thirteen studies involving 172 participants (age range 7-22 years) compared systemic β₂-agonists with placebo, with 12 studies involving oral and one study involving intravenous salbutamol. A significant effect was detected for systemic β₂-agonists on endurance time to exhaustion at 80-85% VO₂(max) (MD 402 s; 95% CI 34, 770; two studies), but not for VO₂(max) (placebo 42.5 ± 1.7 mL · kg⁻¹ · min⁻¹, salbutamol 42.1 ± 2.9 mL · kg⁻¹ · min⁻¹, one study), endurance time to exhaustion at 70% VO₂(max) (MD 400 s; 95% CI -408, 1208; one study) or power output at 90% VO₂(max) (placebo 234.9 ± 16 W, salbutamol 235.5 ± 18.1 W, one study). A significant effect was shown for systemic β₂-agonists on peak power (MD 0.91 W · kg⁻¹; 95% CI 0.25, 1.57; four studies), but not on total work (MD 7.8 J · kg⁻¹; 95% CI -3.3, 18.9; four studies) during a 30-second Wingate test. There were no randomized controlled trials assessing the effects of systemic formoterol, salmeterol or terbutaline on physical performance. In conclusion, no significant effects were detected for inhaled β₂-agonists on endurance, strength or sprint performance in healthy athletes. There is some evidence indicating that systemic β₂-agonists may have a positive effect on physical performance in healthy subjects, but the evidence base is weak.

In the Netherlands an estimated 20,000 people use anabolic androgenic steroids (AAS). The use of AAS is particularly common in regular visitors to gyms and fitness centres. AAS are usually synthetic derivatives of testosterone with both an anabolic and an androgenic effect. AAS have many side effects like liver damage (oral use) or infections (intramuscular use), which can be explained partly by the androgenic effect and partly by the manner of use. Many of these side effects are only reported in case studies and have not been systematically investigated.

Nutritional supplements can be a source of positive doping cases as some supplements contain prohibited substances without showing this on their label. This problem has existed for some time and has been extensively studied in the past 8 years. The sport of tennis has played a particular role in this problem because of some peculiar doping cases within its community. This article focuses on this particular doping problem, explaining the background and reviewing the available literature. It presents the first 3 years of experience within the Netherlands Security System Nutritional Supplements Elite Sports ("Nederlands Zekerheidssysteem Voedingssupplementen Topsport" or NZVT) and explains the most extensive system established to combat this particular doping problem. The NZVT experience has shown that paper-based quality systems are still prone to possible contaminations, which leads to the conclusion that the best possible solution for athletes who wish to use nutritional supplements must include laboratory-based analysis for doping substances, preferably repeated for every new batch. The most important educational message, however, is to use a nutritional supplement only if it is deemed of benefit by a nutritional expert.