A national anti-doping education programme reduces doping susceptibility in British athletes.

The World Anti-Doping Agency's International Standard for Education instructs that national and international sport organisations evaluate their education programmes. We addressed this directive by examining the effectiveness of a national anti-doping programme. Athletes (N = 302, 41% female) completed measures of doping susceptibility, intention to use dietary supplements, Spirit of Sport and moral values, anti-doping knowledge and practice, and whistleblowing, prior-to and three-months after attending an anti-doping education programme. At three-month follow-up, athletes reported decreased doping susceptibility and intention to use dietary supplements coupled with increased importance of values, anti-doping knowledge, anti-doping practice and whistleblowing. Within-participant, moderated-mediation analyses revealed that programme-related changes in doping susceptibility were indirectly related to changes in intention to use dietary supplements, and, that this indirect relationship was moderated by moral values. These findings confirm the effectiveness of a national anti-doping education programme and highlight the contribution of dietary supplement use and personal values to changes in doping susceptibility.

Are dietary supplement users more likely to dope than non-users?: A systematic review and meta-analysis.

In the past decade, a body of evidence has reported that dietary supplement use is related to prohibited performance enhancing substance use (i.e., doping). To help international and national sport organisations understand the degree to which dietary supplement use is related to doping, the objectives of this systematic review and meta-analysis were to 1) compare the prevalence of doping between dietary supplement users and non-users and 2) identify whether supplement use is related to doping social cognitive factors. We searched for studies sampling athletes and that measured both dietary supplement use and doping in EMBASE, MEDLINE, PsychINFO, CINAHL and SPORTDiscus from database creation to May 2022. Risk of bias was assessed using JBI Critical Appraisal Checklist for cross-sectional studies and the STROBE checklist. Twenty-six cross-sectional studies, involving 13,296 athletes were included. Random-effect models revealed that doping was 2.74 (95% CI=2.10 to 3.57) times more prevalent in dietary supplement users (pooled prevalence = 14.7%) than non-users (6.7%), and that users reported stronger doping intentions (r=0.26, 0.18 to 0.34) and attitudes (r=0.21, 0.13 to 0.28) compared to non-users. Preliminary evidence also suggests that dietary supplement users were less likely to dope if they were more task oriented and had a stronger sense of morality. Results of the review are limited by the cross-sectional design used in all studies and lack of consistency in measurement of dietary supplement use and doping. Data indicate that athletes using dietary supplements are more likely to self-report doping Anti-doping policy should, therefore, target dietary supplement use in anti-doping education programmes by providing alternative strategies for performance enhancement or highlighting the safest ways they can be consumed. Similarly, as a large proportion of athletes use dietary supplements without doping, further research is needed to understand the factors that protect a dietary supplement user from doping. No funding was received for the review. A study protocol can be found here: https://osf.io/xvcaq.

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

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

Efficacy of sodium bicarbonate ingestion strategies for protecting blinding.

Sodium bicarbonate (NaHCO3) is a widely researched ergogenic aid, but the optimal blinding strategy during randomised placebo-controlled trials is unknown. In this multi-study project, we aimed to determine the most efficacious ingestion strategy for blinding NaHCO3 research. During study one, 16 physically active adults tasted 0.3 g kg-1 body mass NaHCO3 or 0.03 g kg-1 body mass sodium chloride placebo treatments given in different flavour (orange, blackcurrant) and temperature (chilled, room temperature) solutions. They were required to guess which treatment they had received. During study two, 12 recreational athletes performed time-to-exhaustion (TTE) cycling trials (familiarisation, four experimental). Using a randomised, double-blind design, participants consumed 0.3 g kg-1 body mass NaHCO3 or a placebo in 5 mL kg-1 body mass chilled orange squash/water solutions or capsules and indicated what they believed they had received immediately after consumption, pre-TTE and post-TTE. In study one, NaHCO3 prepared in chilled orange squash resulted in the most unsure ratings (44%). In study two, giving NaHCO3 in capsules resulted in more unsure ratings than in solution after consumption (92 vs 33%), pre-TTE (67 vs. 17%) and post-TTE (50 vs. 17%). Administering NaHCO3 in capsules was the most efficacious blinding strategy which provides important implications for researchers conducting randomised placebo-controlled trials.

Moral values and moral identity moderate the indirect relationship between sport supplement use and doping use via sport supplement beliefs.

The Incremental Model of Doping Behaviour suggests doping grows out of the habitual use of performance-enhancing methods (e.g., sport supplements) and belief that they are necessary for performance. Importantly, in this model, doping is viewed as functional rather than moral choice. In two studies, we examined whether sport supplement use was indirectly related to doping use via sport supplement beliefs, and whether personal morality moderated this relationship. Competitive athletes (Study 1, N = 366; Study 2, N = 200) completed measures of supplement use, beliefs, and doping use. They also completed measures of moral values (Study 1) and moral identity (Study 2). In both studies, supplement use was indirectly related to doping use via beliefs. Moreover, this indirect relationship was moderated by moral values (Study 1) and moral identity (Study 2). That is, the relationship between supplement use and doping use via beliefs was negated when moral values and moral identity were high but not when they were low or moderate. Taken together, our findings suggest that sport supplement users, who believe they are necessary, are more likely to dope if they have low moral values and believe that being a moral person is unimportant to their self-image.

Athletes using ergogenic and medical sport supplements report more favourable attitudes to doping than non-users.

OBJECTIVES: Our study objectives were twofold: 1) examine whether users and non-users of different types of sport supplements vary in doping attitudes and sport supplement beliefs, and 2) determine whether the type of sport supplement is directly and indirectly (via sport supplement beliefs) related to doping attitudes. DESIGN: Cross-sectional survey. METHODS: Athletes (N=557; 77% male, mean±standard deviation; age=20.8±4.5 years, training=5.7±4.2h per week, competing=11.1±5.2 years) completed measures of sport supplement use, sport supplement beliefs, and doping attitudes. Sport supplements were classified into: ergogenic, medical, sport food and drinks, and superfoods. RESULTS: Compared to non-users, users of ergogenic (d=0.31, p<0.01) and medical (d=0.42, p<0.01) sport supplements reported more favourable attitudes towards doping. In addition, compared to non-users, users of ergogenic (d=1.10, p<0.01), medical (d=0.80, p<0.01) and sport food/drink (d=0.58, p<0.01) supplements reported stronger beliefs in the effectiveness of sport supplements to improve sport performance. Use of ergogenic, medical and sport food/drink supplements was indirectly related to doping attitudes via sport supplement beliefs. CONCLUSIONS: Researchers examining the relationship between sport supplement use and doping should differentiate between sport supplement types to improve measurement accuracy. Sport practitioners administering ergogenic and medical sport supplements to athletes may need to provide additional anti-doping education to counteract any favourable attitudes towards doping.

No Differences Between Beetroot Juice and Placebo on Competitive 5-km Running Performance: A Double-Blind, Placebo-Controlled Trial.

The authors examine the effect of an acute dose of beetroot juice on endurance running performance in "real-world" competitive settings. In total, 70 recreational runners (mean ± SD: age = 33.3 ± 12.3 years, training history = 11.9 ± 8.1 years, and hours per week training = 5.9 ± 3.5) completed a quasi-randomized, double-blind, placebo-controlled study of 5-km competitive time trials. Participants performed four trials separated by 1 week in the order of prebaseline, two experimental, and one postbaseline. Experimental trials consisted of the administration of 70-ml nitrate-rich beetroot juice (containing ∼4.1 mmol of nitrate, Beet It Sport®) or nitrate-depleted placebo (containing ∼0.04 mmol of nitrate, Beet It Sport®) 2.5 hr prior to time trials. Time to complete 5 km was recorded for each trial. No differences were shown between pre- and postbaseline (p = .128, coefficient variation = 2.66%). The average of these two trials is therefore used as baseline. Compared with baseline, participants ran faster with beetroot juice (mean differences = 22.2 ± 5.0 s, p < .001, d = 0.08) and placebo (22.9 ± 4.5 s, p < .001, d = 0.09). No differences in times were shown between beetroot juice and placebo (0.8 ± 5.7 s, p < .875, d = 0.00). These results indicate that an acute dose of beetroot juice does not improve competitive 5-km time-trial performance in recreational runners compared with placebo.

The Placebo and Nocebo effect on sports performance: A systematic review.

The aim of this review was to determine the magnitude of the placebo and nocebo effect on sport performance. Articles published before March 2019 were located using Medline, Web of Science, PubMed, EBSCO, Science Direct, and Scopus. Studies that examined placebo and nocebo effects of an objective dependent variable on sports performance, which included a control or baseline condition, were included in the analysis. Studies were classified into two categories of ergogenic aids: (1) nutritional and (2) mechanical. Cohen's d effect sizes were calculated from 32 studies involving 1513 participants. Small to moderate placebo effects were found for both placebo (d = 0.36) and nocebo (d = 0.37) effects and when separated by nutritional (d = 0.35) and mechanical (d = 0.47) ergogenic aids. The pooled effect size revealed a small to moderate effect size across all studies (d = 0.38). Results suggest that placebo and nocebo effects can exert a small to moderate effect on sports performance.

Sport supplement use predicts doping attitudes and likelihood via sport supplement beliefs.

The aim of this study was to examine: 1) whether sport supplement use is related to doping and 2) whether sport supplement beliefs mediated this relationship. In Study 1, athletes (N = 598), completed measures of sport supplement use, sport supplement beliefs, and doping attitudes. In Study 2, athletes (N = 475) completed measures of sport supplement use, sport supplement beliefs, and doping likelihood. In both studies, sport supplement use predicted doping outcomes indirectly via sport supplement beliefs. Our findings provide novel evidence to suggest that sport supplement users, who strongly believe that sport supplements are effective, are more likely to dope. For anti-doping organisations wishing to prevent doping, targeting an athlete's beliefs about sport supplements may improve the effectiveness of anti-doping prevention programmes.

Athletes Intending to Use Sports Supplements Are More Likely to Respond to a Placebo.

PURPOSE: We investigated associations between athletes' use of sport supplements and their responsiveness to placebo and nocebo interventions. METHODS: Participants (n = 627) reported their intention to use, and actual use of, sport supplements. They then completed a 5 × 20 m repeat sprint protocol in the baseline condition, before being randomized to one of three treatments. Participants in the positive-belief treatment were administered an inert capsule described as a potent supplement which would improve sprint performance. Participants in the negative-belief treatment were administered an inert capsule described as a potent supplement which would negatively affect sprint performance. Participants in the control treatment received neither instruction nor capsule. Twenty minutes after baseline trials, all participants completed the same repeat sprint protocol in the experimental condition. RESULTS: Compared with controls, no mean differences in performance were observed between baseline and experimental conditions for the positive-belief treatment (-0.07% ± 0.27%, d = 0.02), but mean differences were observed for the negative-belief treatment (-0.92% ± 0.31%, d = 0.32), suggesting a moderate nocebo effect. In the positive-belief treatment, however, a relationship between intention to use supplements and performance was observed. Performance worsened by -1.10% ± 0.30% compared with baseline for participants not intending to use supplements, worsened by -0.64% ± 0.43% among those undecided about supplement use, but improved by 0.19% ± 0.24% among those participants intending to use supplements. CONCLUSIONS: Information about a harmful supplement worsened repeat sprint performance (a mean nocebo effect), whereas information about a beneficial supplement did not improve performance (no mean placebo effect was observed). However, participants' intention to use sport supplements influenced the direction and magnitude of subsequent placebo responses, with participants intending to use supplements more likely to respond to the positive intervention.