Influence of short-term chronic oral cannabidiol application on muscle recovery and performance after an intensive training protocol - a randomized double-blind crossover study.

BACKGROUND: Rapid regeneration after intense exercise is essential for competitive athletes. Based on this assumption, supplementation strategies, focusing on food supplements, are increasing to improve the recovery processes. One such supplement is cannabidiol (CBD) which is gaining more attention in competitive sports. However, the evidence is still lacking and there are no data available about the effect of a short-term chronic application. METHODS: A three-arm double-blind cross-over study was conducted to determine the effects of two different CBD products on performance, muscle damage and inflammatory processes in well-trained athletes. In total 17 subjects took successfully part in this study. Each subject underwent the six-day, high-intensity training protocol three times. After each training session, each subject took either a placebo or a CBD product (60 mg of oil or solubilisate). Between the intervention phases, at least four weeks of washout period was conducted. Before and after the training protocols the performance capacity in countermovement jump (CMJ), back squat (BS), bench press (BP) and 1-mile run were measured and biomarkers for muscle damage (creatine kinase, myoglobin), inflammatory processes (interleukin 6 and 10) and immune cell activity (ratios of neutrophil granulocytes, lymphocytes and, platelets) were analyzed. For statistical analyses, the current version of R and a linear mixed model was used. RESULTS: It could identify different effects of the training protocol depending on performance level (advanced or highly advanced athletes) (p < .05). Regardless of the performance level, muscle damage and a reduction in performance could be induced by the training protocol. Only CBD oil was associated with a reduction in myoglobin concentration (p < .05) in advanced athletes. Concerning immune activity, a significant decrease in platelets lymphocyte ratios was observed in advanced athletes after placebo treatment (p < .05). CBD oil application showed a slight inhibitory effect (p < .10). Moreover, the reduction in performance differs between the performance levels. A significant decrease in CMJ was observed in advanced athletes and a decreasing trend in BS was observed in highly advanced athletes after placebo treatment (p < 0.10). Both CBD products do not affect performance parameters. For inflammatory parameters, no effects were observed. CONCLUSION: It was found that the performance level of the subjects was a decisive factor and that they responded differently to the training protocol and the CBD application. However, no clear effects of either CBD product were found and further research is needed to identify the long-term effects of CBD application.

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.

Resistance training alters body composition in middle-aged women depending on menopause - A 20-week control trial.

BACKGROUND: Resistance training (RT) is effective in counteracting the age- and menopause-related loss of muscle mass (MM) and strength in middle-aged women (40-60 years). Research on RT with free weights is limited in pre- and post-menopausal women. Based on this, a 20-week training intervention was conducted with this population to investigate the effects of systematic RT with free weights on strength capacity and body composition. METHOD: Forty-one healthy women (52.0 ± 3.6 years) participated in this study. After 10-week control phase (no RT, T0-T1) followed by a 10-week intervention phase (T1-T2) with RT twice a week and 6-8 sets of each muscle per week. Subjects were randomly assigned to a low-intensity (50% 1-RM) or moderate-intensity (75% 1-RM) RT group and divided into pre-menopausal and post-menopausal according to their hormone profile. Fat-free mass (FFM), MM, fat mass (FM), muscle thickness (Vastus lateralis (VL), Rectus femoris (RF), Triceps brachii (TB)), grip strength, 1-RM squat and bench press were assessed before and after each phase. Statistical analysis was performed using a linear mixed model to account for fixed (time and group) and random (individual) effects. RESULTS: A total of 31 women successfully completed the study. No injuries occurred during the intervention. Significant increases in 1-RM squat and bench press were observed in all groups. No interaction effect was observed for the strength parameters. In pre-menopausal women, FFM, MM and RF muscle thickness increased significantly, while VL showed a trend. These effects were not present in post-menopausal women regardless of RT intensity. CONCLUSION: RT with free weight is safe and effective for middle-aged women to increase 1-RM. Hypertrophy effects were found exclusively in pre-menopausal women. To achieve hypertrophy and/or body composition changes in post-menopausal women, larger training volumes (> 6-8 sets/muscle per week) are likely required.

The Anabolic Effect of Fenugreek: A Systematic Review with Meta-analysis.

The use of plant steroids to improve physical health and performance is becoming increasingly popular. One of these plant steroids is diosgenin, which is mainly available in fenugreek. As a result, some studies have been conducted to improve physical health. Fenugreek extracts are also becoming increasingly popular in the context of athletic performance. Based on these assumptions, a systematic review with meta-analysis was conducted to evaluate the promoting effects of fenugreek on strength performance, body composition, and hormone concentration. Four databases were screened according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The current version of ReviewManager (RevMan) was used for the statistical evaluation. Seven studies with 449 participants (378 male, 71 female) met the inclusion criteria. A small effect of fenugreek was detected for total testosterone (standard mean difference (SMD): 0.32; 95% confidence interval (CI): 0.09 0.55), free testosterone (SMD: 0.24; 95% CI: -0.04, 0.52), lean body mass (SMD: 0.19; 95% CI: -0.10, 0.49), fat mass (SMD: -0.19; 95% CI: -0.44, 0.05), and leg press performance (SMD: 0.22; 95% CI: -0.02, 0.47), in male athletes. The meta-analysis shows that chronic application of fenugreek has performance-enhancing and anabolic effects in male athletes, but no statements can be made for female athletes.

Combinatory Effects of Training and Nutritive Administration of Carbohydrates and Protein via Food on Strength in Postmenopausal Women, and Old Men and Women.

The age-related loss of muscle mass promotes many impairments. Training and protein supplementation are suggested to prevent muscle wasting, but recommendations for all populations are not based on scientific evidence. This study combines protein/carbohydrate supplementation (PCS) and training for seniors and postmenopausal women. Project A: 51 postmenopausal women (PMW, 57.3 ± 3.0 years old) underwent health-oriented training (12 weeks, moderate-strength training + moderate-endurance training). The intervention group (IG) additionally received 110 g sour milk cheese (SMC) and toast. Project B: 25 women and 6 men (65.9 ± 4.9 years old) performed intense sling training (12 weeks). The IG additionally received 110 g SMC, toast, and buttermilk. Strength was tested before and after in both studies. Project A: there was significant increase in strength, no additional effect of PCS, and a reduction in body fat in the controls. Project B: there was significant increase in strength, significant additional effects of PCS for trunk strength, and a significant reduction in body weight. Combining training and PCS may counteract strength loss. Combined endurance/resistance training is recommended to PMW for whom the benefits of PCS are restricted. Aged subjects may benefit from PCS when training intensely, but these benefits may be strongly individual.

Effects of Carbohydrate and Protein Administration by Food Items on Strength Response after Training in Stable COPD.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is one of the world's most common diseases and reasons for death. Systemic consequences, especially reduced muscle strength, muscle mass and muscle function, are common and contribute to worsening prognosis and increasing morbidity and mortality. There is strong evidence that physical activity and strength training are effective in prolonging life and lead to better quality of life. Numerous studies have shown that ingestion of protein and carbohydrates after strength training can increase regeneration of strength in young athletes. Recently, we demonstrated that the same effect can be achieved with these macronutrients administered in a meal. Until now, it is not clear if patients with COPD, integrated in regular physical training, respond similarly. METHODS: Prescribed strength training, consisting of two sets circular training with machines for big muscle groups was supplemented with a meal rich in protein and carbohydrates. Changes in maximum strength after 24 h were investigated to find out about the impact of this meal on physical capacity. A pilot study was conducted with pragmatic cross-over design. RESULTS: With nutritive intervention, strength in both knee extensor and chest press were significantly higher than in control training. CONCLUSION: The study showed beneficial effects for the intake of protein and carbohydrates in changes in maximum strength. For now, the underlying mechanism remains unclear. Clinical relevance needs further research. The study design and study protocol can be used for further studies with only small adaptions.

Hormonal response after masturbation in young healthy men - a randomized controlled cross-over pilot study.

BACKGROUND: Hormones like testosterone play a crucial role in performance enhancement and muscle growth. Therefore, various attempts to increase testosterone release and testosterone concentration have been made, especially in the context of resistance training. Among practitioners, sexual activity (coitus and masturbation) a few hours before training is often discussed to result in increases of testosterone concentration and thus promote muscle growth. However, there is no evidence to support this assumption and the kinetics of the testosterone and cortisol response after sexual activity have not been adequately investigated. Therefore, the aim of this pilot-study was to examine the kinetics of hormone concentrations of total testosterone, free testosterone and cortisol and their ratios after masturbation. In a three-arm single blinded cross-over study, the effects of masturbation with visual stimulus were compared to a visual stimulus without masturbation and the natural kinetics in healthy young men. RESULTS: The results showed a significant between-condition difference in free testosterone concentrations. Masturbation (p < 0.01) and a visual stimulus (p < 0.05) may seem to counteract the circadian drop of free testosterone concentrations over the day. However, no statistical change was observed in the ratios between total testosterone, free testosterone and cortisol. CONCLUSIONS: It can be assumed that masturbation may have a potential effect on free testosterone concentrations but not on hormonal ratios. However, additional studies with larger sample sizes are needed to validate these findings.

RéSUMé: CONTEXTE: Les hormones comme la testostérone jouent un rôle crucial dans l'amélioration des performances et dans la croissance musculaire. Par conséquent, diverses tentatives pour augmenter la libération de testostérone et la concentration de testostérone ont été faites, en particulier dans le contexte de l'entraînement à la résistance. Chez les praticiens, l'activité sexuelle (le coït et la masturbation) quelques heures avant l'entraînement est souvent évoquée comme induisant une augmentation de la concentration de testostérone et favorisant ainsi la croissance musculaire. Il n'existe, cependant, aucune preuve à l'appui de cette hypothèse et la cinétique de la réponse de la testostérone et du cortisol après l'activité sexuelle n'a pas été étudiée de manière adéquate. Par conséquent, l'objectif de cette étude pilote était d'examiner la cinétique des concentrations hormonales de testostérone totale, de testostérone libre et de cortisol et de leurs ratios après la masturbation. Dans une étude croisée à trois bras en simple aveugle, les effets de la masturbation avec stimulus visuel ont été comparés à un stimulus visuel sans masturbation et à la cinétique naturelle chez des hommes jeunes en bonne santé. RéSULTATS: Les résultats ont montré, pour les concentrations de testostérone libre, une différence significative entre les conditions. La masturbation (p < 0,01) et un stimulus visuel (p < 0,05) pourraient sembler contrecarrer la baisse circadienne des concentrations de testostérone libre au cours de la journée. Cependant, aucun changement statistique n'a été observé dans les ratios entre la testostérone totale, la testostérone libre et le cortisol. CONCLUSION: On peut supposer que la masturbation peut avoir un effet potentiel sur la testostérone libre mais pas sur les ratios hormonaux. D'autres études, avec des échantillons de plus grande taille, sont cependant nécessaires pour valider ces résultats.

Effects of Cannabidiol Supplementation on Skeletal Muscle Regeneration after Intensive Resistance Training.

Cannabidiol supplements (CBD) are increasingly consumed by athletes to improve regeneration. However, the evidence for the pro-regenerative effects of CBD in sports is quite limited. Therefore, our aim was to investigate the effects of a single CBD supplementation in a six-arm placebo-controlled crossover study after resistance training on performance and muscle damage. Before and after the resistance training, one-repetition maximum in the back squat (1RM BS), countermovement jump (CMJ), and blood serum concentrations of creatine kinase (CK) and myoglobin (Myo) were measured in healthy, well-trained participants. 16 out of 21 participants completed the study and were included in the analysis. In 1RM BS, a significant decrease was observed after 24 h (p < 0.01) but not after 48 and 72 h. A significant group difference was detected after 72 h (p < 0.05; ES = 0.371). In CMJ, no significant changes were observed. The CK and Myo concentrations increased significantly after 24 h (CK: p < 0.001; Myo: p < 0.01), 48 h (CK: p < 0.001; Myo: p < 0.01) and 72 h (CK: p < 0.001; Myo: p < 0.001). After 72 h, significant group differences were observed for both muscle damage biomarkers (CK: p < 0.05 ES = 0.24; Myo: p < 0.05; ES = 0.21). The results show small but significant effects on muscle damage and recovery of squat performance after 72 h. However, more data are required for clearer statements concerning potential pro-regenerative effects of CBD supplementation after resistance training.

Case Study: Atypical δ13 C values of urinary norandrosterone.

Isotope ratio mass spectrometry (IRMS) has been established in doping control analysis to identify the endogenous or exogenous origin of a variety of steroidal analytes including the 19-norsteroid metabolite norandrosterone (NorA). NorA can be found naturally in human urine in trace amounts due to endogenous demethylation or in situ microbial degradation. The administration of nortestosterone (nandrolone) or different prohormones results in the excretion of urinary NorA. Usually, this can be detected by IRMS due to differing δ13 C values of synthetic 19-norsteroids compared to endogenous reference compounds. The consumption of uncastrated pig edible parts like offal or even meat may also lead to a urinary excretion of NorA. In order to determine the δ13 C values of such a scenario, urine samples collected after consumption of a wild-boar-testicle meal were analyzed. IRMS revealed highly enriched δ13 C values for urinary NorA, which could be related to the completely corn-based nutrition of the animal. Isotopic analysis of the boar's bristles demonstrated a dietary change from C3 -based forage, probably in winter and spring, to a C4 -based diet in the last weeks to months prior to death. These results supported the interpretation of an atypical test result of a Central European athlete's doping control sample with δ13 C values for NorA of -18 ‰, most probably caused by the consumption of a wild boar ragout. As stated before, athletes should be fully aware of the risk that consumption of wild boar may result in atypical or even adverse analytical findings in sports drug testing.

Do we excrete what we eat? Analysis of stable nitrogen isotope ratios of human urinary urea.

RATIONALE: Natural stable nitrogen isotope ratios (δ15 N) are frequently used for the determination of provenance and dietary assessment of recent and ancient humans. Although individual δ15 N values typically correspond to the dietary δ15 N composition, they are also affected by metabolic conditions. Preferred matrices for the measurement of human δ15 N values have been hair, nail or blood. The goal of this study was to validate a novel approach for the assessment of the δ15 N values from urinary urea, the principal end-product of human N metabolism. METHODS: The method, which involves the precipitation of urea from urine using xanthydrol, was validated using fortified urea solutions. Intra- and inter-individual variance of the δ15 N values of urinary urea was determined from samples obtained from multiple human subjects. RESULTS: Precipitation with xanthydrol did not alter the δ15 N values of urea. The mean δ15 N value in urinary urea from human subjects from Germany was +4.4 ± 0.6 ‰, which corresponds to the estimated dietary composition. It falls below previously reported δ15 N values for human tissue and blood samples. Longitudinal analyses over 7 days illustrate short-time changes linked to varying protein intake. CONCLUSIONS: Our results indicate that δ15 N values can be measured reliably from human urine and that the method is suitable to monitor rapid dietary and metabolic changes of an individual. Our findings further confirm that urinary urea is depleted in 15 N compared with human tissue but within the range of the δ15 N composition of the diet. Copyright © 2017 John Wiley & Sons, Ltd.

Prediction of human dietary δ15N intake from standardised food records: validity and precision of single meal and 24-h diet data.

Natural stable isotope ratios (δ15N) of humans can be used for nutritional analyses and dietary reconstruction of modern and historic individuals and populations. Information about an individual's metabolic state can be obtained by comparison of tissue and dietary δ15N. Different methods have been used to estimate dietary δ15N in the past; however, the validity of such predictions has not been compared to experimental values. For a total of 56 meals and 21 samples of 24-h diets, predicted and experimental δ15N values were compared. The δ15N values were predicted from self-recorded food intake and compared with experimental δ15N values. Predicted and experimental δ15N values were in good agreement for meals and preparations (r = 0.89, p < .001) as well as for the 24-h diets (r = 0.76, p < .001). Dietary δ15N was mainly determined by the amount of fish, whereas the contribution of meat to dietary δ15N values was less pronounced. Prediction of human dietary δ15N values using standardised food records and representative δ15N data sets yields reliable data for dietary δ15N intake. A differentiated analysis of the primary protein sources is necessary when relating the proportion of animal-derived protein in the diet by δ15N analysis.

Global spatial distributions of nitrogen and carbon stable isotope ratios of modern human hair.

RATIONALE: Natural stable carbon (δ(13)C) and nitrogen isotope ratios (δ(15)N) of humans are related to individual dietary habits and environmental and physiological factors. In forensic science the stable isotope ratios of human remains such as hair and nail are used for geographical allocation. Thus, knowledge of the global spatial distribution of human δ(13)C and δ(15)N values is an essential component in the interpretation of stable isotope analytical results. METHODS: No substantial global datasets of human stable isotope ratios are currently available, although the amount of available (published) data has increased within recent years. We have herein summarised the published data on human global δ(13)C andδ(15)N values (around 3600 samples) and added experimental values of more than 400 additional worldwide human hair and nail samples. In order to summarise isotope ratios for hair and nail samples correction factors were determined. RESULTS: The current available dataset of human stable isotope ratios is biased towards Europe and North America with only limited data for countries in Africa, Central and South America and Southeast Asia. The global spatial distribution of carbon isotopes is related to latitude and supports the fact that human δ(13)C values are dominated by the amount of C4 plants in the diet, either due to direct ingestion as plant food, or by its use as animal feed. In contrast, the global spatial distribution of human δ(15)N values is apparently not exclusively related to the amount of fish or meat ingested, but also to environmental factors that influence agricultural production. CONCLUSIONS: There are still a large proportion of countries, especially in Africa, where there are no available data for human carbon and nitrogen isotope ratios. Although the interpretation of modern human carbon isotope ratios at the global scale is quite possible, and correlates with the latitude, the potential influences of extrinsic and/or intrinsic factors on human nitrogen isotope ratios have to be taken into consideration.

Effects of estradiol, estrogen receptor subtype-selective agonists and genistein on glucose metabolism in leptin resistant female Zucker diabetic fatty (ZDF) rats.

The leptin resistant Zucker diabetic fatty (ZDF) rats are hyperphagic and become obese, but whereas the males develop type 2 diabetes mellitus (T2DM), the females remain euglycaemic. As estrogen deficiency is known to increase the risk of developing T2DM, we evaluated the role of ER subtypes alpha and beta in the development of glucose tolerance in leptin resistant ovariectomized (OVX) ZDF rats. At least six rats per group were treated with either vehicle (OVX), 17ß-estradiol (E2), ER subtype-selective agonists (Alpha and Beta), or genistein (Gen) for 17 weeks. At the end of the treatment period a glucose tolerance assay was performed and the metabolic flux of (13)C-glucose for the E2 group was investigated. OVX ZDF rats treated with E2, Alpha, Beta, and Gen tolerated the glucose significantly better than untreated controls. E2 treatment increased absorbance/flux of (13)C-glucose to metabolic relevant tissues such liver, adipose tissue, gastrocnemius, and soleus muscle. Moreover, whereas Alpha treatment markedly increased mRNA expression of GLUT4 in gastrocnemius muscle, Beta treatment resulted in the largest fiber sizes of the soleus muscle. Treatment with Gen increased both the mRNA expression of GLUT 4 and the fiber sizes in the skeletal muscle. In addition, E2 and Alpha treatment decreased food intake and body weight gain. In summary, estrogen-improved glucose absorption is mediated via different molecular mechanisms: while activation of ER alpha seems to stimulate muscular GLUT4 functionality, activation of ER beta results in a hypertrophy of muscle fibers. In addition, selective activation of ER alpha decreased food intake and body weight gain. Our data further indicate that ER subtype-selective agonists and genistein improve systemic glucose tolerance also in the absence of a functional leptin signaling pathway.

Physiological and metabolic responses as function of the mechanical load in resistance exercise.

The present study aimed to investigate the relationship between the mechanical load during resistance exercise and the elicited physiological responses. Ten resistance-trained healthy male subjects performed 1 set of resistance exercise each at 55%, 70%, and 85% of 1 repetition maximum for as many repetitions as possible and in 4 training modes: 4-1-4-1 (4 s concentric, 1 s isometric, 4 s eccentric, and 1 s isometric successive actions), 2-1-2-1, 1-1-1-1, and explosive (maximum velocity concentric). Mean concentric power and total concentric work were determined. Oxygen uptake (V̇O2) was measured during exercise and for 30 min post exercise. Total volume of consumed oxygen (O2 consumed) and excess post-exercise oxygen consumption (EPOC) were calculated. Maximum blood lactate concentration (LAmax) was also determined. V̇O2 exhibited a linear dependency on mean concentric power. Mean concentric power did not have a detectable effect on EPOC and LAmax. An augmentation of total concentric work resulted in significant linear increase of O2 consumed and EPOC. Total concentric work caused a significant increase in LAmax. In general, a higher mechanical load induced a larger physiological response. An increase in mean concentric power elicited higher aerobic energy turnover rates. However, a higher extent of total concentric work augments total energy cost covered by oxidative and (or) glycolytic pathways.

Molecular effects of ER alpha- and beta-selective agonists on regulation of energy homeostasis in obese female Wistar rats.

The molecular mechanisms underlying the effects of selective ER subtype activation on lipogenesis, adipogenesis, lipid utilization and storage as well as glucose metabolism are currently largely unknown and were analyzed in female OVX Wistar rats on a high-fat diet. Rats received estradiol (E2), ER subtype-selective agonists (Alpha and Beta), and genistein (Gen) for 10 weeks. In adipose tissue, treatment with E2, Alpha, and Beta significantly decreased lipogenic (SREBP-1c, FAS) and adipogenic genes (LPL, PPAR gamma). In liver and skeletal muscle of E2-, Alpha-, Beta-, and Gen-treated animals, lipogenesis and triglyceride accumulation were significantly reduced. Increased hepatic and muscular PPAR gamma mRNA expression was observed in untreated, Beta- and Gen-treated animals, which correlates with increased hepatic glucose uptake. However, only untreated animals showed impaired insulin sensitivity compared to all other groups. Therefore, PPAR gamma up-regulation in untreated animals suggests a compensatory mechanism, probably due to increased triglyceride accumulation in non-adipose tissues. Beta- and Gen-treated animals may benefit from the anabolic potency of ER beta that ameliorates lipid and glucose utilization in muscle. Activation of either ER subtype reduces fat enrichment and improves insulin sensitivity. Depending on the investigated tissue, different molecular pathways seem to be involved.

Traditional Chinese medicine and sports drug testing: identification of natural steroid administration in doping control urine samples resulting from musk (pod) extracts.

The administration of musk extract, that is, ingredients obtained by extraction of the liquid secreted from the preputial gland or resulting grains of the male musk deer (eg, Moschus moschiferus), has been recommended in Traditional Chinese Medicine (TCM) applications and was listed in the Japanese pharmacopoeia for various indications requiring cardiovascular stimulation, anti-inflammatory medication or androgenic hormone therapy. Numerous steroidal components including cholesterol, 5α-androstane-3,17-dione, 5ß-androstane-3,17-dione, androsterone, etiocholanolone, epiandrosterone, 3ß-hydroxy-androst-5-en-17-one, androst-4-ene-3,17-dione and the corresponding urea adduct 3α-ureido-androst-4-en-17-one were characterised as natural ingredients of musk over several decades, implicating an issue concerning doping controls if used for the treatment of elite athletes. In the present study, the impact of musk extract administration on sports drug testing results of five females competing in an international sporting event is reported. In the course of routine doping controls, adverse analytical findings concerning the athletes' steroid profile, corroborated by isotope-ratio mass spectrometry (IRMS) data, were obtained. The athletes' medical advisors admitted the prescription of TCM-based musk pod preparations and provided musk pod samples for comparison purposes to clarify the antidoping rule violation. Steroid profiles, IRMS results, literature data and a musk sample obtained from a living musk deer of a local zoo conclusively demonstrated the use of musk pod extracts in all cases which, however, represented a doping offence as prohibited anabolic-androgenic steroids were administered.

Validity of stable isotope data in doping control: perspectives and proposals.

Δ(13)C and δ(13)C values of endogenous urinary steroids represent physiological random variables. Measurement uncertainty and biological scatter likewise contribute to the variances. The statistical distributions of negative controls are well investigated, but there is little knowledge about the corresponding distributions of steroid-users. For these reasons valid discrimination of steroid users from non-users by (13)C/(12)C analysis of endogenous steroids requires elaborate statistical treatment. Corresponding Bayesian approaches are presented following an introduction to the rationale. The use of mixture models appears appropriate. The distribution of routine data has been deconvolved and characterized accordingly. The mixture components, which presumably represent steroid users and non-users, exhibit considerable overlap. The validity of a given result depends on both the analytical uncertainty and the prior probability of doping offenses. Low analytical uncertainties but high prior probabilities facilitate valid detection of doping offenses. Two recommendations can be deduced. First, before starting an (13)C/(12)C analysis, any initial suspicion should be well-substantiated. This precludes use of permissive criteria derived from the steroid profile. Secondly, knowledge of relevant (13)C/(12)C distributions is required. This must cover representative numbers of authentic steroid users. Finally, it is desirable that the conditional probability for steroid administration rather than the measurement uncertainty is calculated and reported. This quantity possesses superior validity and it is largely independent of laboratory bias. The findings suggest and facilitate flexible handling of decision limits. Proposals for the evaluation of stable isotope data are presented.

Isotope ratio mass spectrometry - history and terminology in brief.

The history of isotope ratio mass spectrometry (IRMS) is briefly described. It is shown that the fundamental design of isotope ratio mass spectrometers has not changed since the 1940s. The basic findings concerning the natural variation of isotope abundances even date back to the 1930s. Recent improvements in the methodology mainly concern online coupling and analytical peripherals. The nature of isotopic scales necessitates a specific terminology which is unfamiliar to many analysts. However, corresponding guidelines exist that should be adopted by the anti-doping community. Currently, steroids represent the only group of compounds routinely analyzed by IRMS in doping-control. Suggestions are made in respect to a harmonized terminology concerning the nature and origins of steroids.

Evolving concepts and techniques for anti-doping.

Technical advances are being made in many areas of biotechnology and genetics that are facilitating the detection of doping in sport. These improvements have been catalyzed by the need to counter the ever-increasing sophistication of the community of athletes and their retinues who are intent on the illicit use of physical, pharmacological and genetic tools and methods to enhance athletic performance, in contravention of established international ethical and legal standards and of international treaty. The methods described in this article present a partial and general picture of only some of these advances.

Determination of salbutamol and salbutamol glucuronide in human urine by means of liquid chromatography-tandem mass spectrometry.

The determination of salbutamol and its glucuronide in human urine following the inhalative and oral administration of therapeutic doses of salbutamol preparations was performed by means of direct urine injection utilizing liquid chromatography-tandem mass spectrometry (LC-MS/MS) and employing d(3)-salbutamol and d(3)-salbutamol glucuronide as internal standards. Unconjugated salbutamol was detected in all administration study urine samples. Salbutamol concentrations following inhalation were commonly (99%) below 1000 ng/ml whereas values after oral administration frequently (48%) exceeded this threshold. While salbutamol glucuronide was not detected in urine samples collected after inhalation of the drug, 26 out of 82 specimens obtained after oral application contained salbutamol glucuronide with a peak value of 63 ng/ml. The percentage of salbutamol glucuronide compared to unconjugated salbutamol was less than 3%. Authentic doping control urine samples indicating screening results for salbutamol less than 1000 ng/ml, showed salbutamol glucuronide concentrations between 2 and 6 ng/ml, whereas adverse analytical findings resulting from salbutamol levels higher than 1000 ng/ml, had salbutamol glucuronide values between 8 and 15 ng/ml. The approach enabled the rapid determination of salbutamol and its glucuronic acid conjugate in human urine and represents an alternative to existing procedures since time-consuming hydrolysis or derivatization steps were omitted. Moreover, the excretion of salbutamol glucuronide in human urine following the administration of salbutamol was proven.