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
Method: Athletes (N = 557; 77% male, mean ± standard deviation; age = 20.8 ± 4.5 years, training = 5.7 ± 4.2 hours 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.
1. Garthe I, Maughan RJ. Athletes and supplements: prevalence and perspectives. Int. J. Sport Nutr. Exerc. Metab. 2018; 28(2):126-138.
2. Backhouse SH, Whitaker L, Petroczi A. Gateway to doping? Supplement use in the context of preferred competitive situations, doping attitude, beliefs, and norms. The Scandinavian Journal of Medicine & Science in Sports 2013; 23(2):244-252.
3. Ntoumanis N, Ng JY, Barkoukis V, Backhouse S. Personal and psychosocial predictors of doping use in physical activity settings: a meta-analysis. Sports Med. 2014; 44(11):1603-1624.
4. Sekulic D, Tahiraj E, Zvan M, Zenic N, Uljevic O, Lesnik B. Doping attitudes and covariates of potential doping behaviour in high-level team-sport athletes; gender specific analysis. J. Sports Sci. Med. 2016; 15(4):606.
5. Morente-Sánchez J, Zandonai T, Díaz MZ. Attitudes, beliefs and knowledge related to doping in different categories of football players. J. Sci. Med. Sport. 2019; 22(9):981-986.
6. Maughan RJ, Burke LM, Dvorak J, et al. IOC consensus statement: dietary supplements and the high-performance athlete. Int. J. Sport Nutr. Exerc. Metab. 2018; 28(2):104-125.
7. Garthe I. Dietary supplements and elite athletes: when nature becomes high risk. Current Opinion in Endocrine and Metabolic Research. 2019; 9:66-73.
8. Willoughby DS, Spillane M, Schwarz N. Heavy resistance training and supplementation with the alleged testosterone booster nmda has no effect on body composition, muscle performance, and serum hormones associated with the hypothalamo-pituitary-gonadal axis in resistance-trained males. J. Sports Sci. Med. 2014; 13(1):192.
9. Petróczi A. The doping mindset—Part I: Implications of the Functional Use Theory on mental representations of doping. Perf Enhanc Health. 2013; 2(4):153-163.
10. Petróczi A, Norman P, Brueckner S. Can we better integrate the role of anti-doping in sports and society? A psychological approach to contemporary value-based prevention, in Acute Topics in Anti-Dopinged^eds, Karger Publishers, 2017.
11. Hurst P, Kavussanu M, Boardley ID, Ring C. Sport supplement use predicts doping via sport supplement beliefs. J. Sports Sci. 2019:1-7.
12. Petróczi A, Aidman E. Measuring explicit attitude toward doping: Review of the psychometric properties of the Performance Enhancement Attitude Scale. Psychol. Sport Exerc. 2009; 10(3):390-396.
13. Peeling P, Castell LM, Derave W, de Hon O, Burke LM. Sports foods and dietary supplements for optimal function and performance enhancement in track-and-field athletes. Int. J. Sport Nutr. Exerc. Metab. 2019; 29(2):198-209.
14. Nicholls AR, Madigan DJ, Levy AR. A Confirmatory Factor Analysis of the Performance Enhancement Attitude Scale for adult and adolescent athletes. Psychol. Sport Exerc. 2017; 28:100-104.
15. Petróczi A. Measuring attitude toward doping: Further evidence for the psychometric properties of the Performance Enhancement Attitude Scale. 14th Congress of the European Association for Sport Management. Nicosia, Cyprus2006.
16. Hurst P, Foad AJ, Coleman DA, Beedie C. Development and validation of the Sports Supplements Beliefs Scale Perf Enhanc Health. 2017; 5(3):89-97.
17. Goldammer P, Annen H, Stöckli PL, Jonas K. Careless responding in questionnaire measures: Detection, impact, and remedies. The Leadership Quarterly. 2020:101384.
18. Little RJ. A test of missing completely at random for multivariate data with missing values. J Am Stat Assoc. 1988; 83(404):1198-1202.
19. Van Buuren S. Flexible imputation of missing data, CRC press; 2018.
20. Royston P. Multiple imputation of missing values. The Stata Journal. 2004; 4(3):227-241.
21. Pedersen AB, Mikkelsen EM, Cronin-Fenton D, et al. Missing data and multiple imputation in clinical epidemiological research. Clin. Epidemiol. 2017; 9:157.
22. Lenhard W, Lenhard A. Calculation of effect sizes. https://www.psychometrica.de/effect_size.html.
23. Cohen J. A power primer. Psychol. Bull. 1992; 112(1):155-159.
24. Hayes AF. Introduction to Mediation, Moderation, and Conditional Process Analysis: A Regression-Based Approach (Methodology in the Social Sciences), New York, NY, Guilford-Press; 2013.
25. Gignac GE, Szodorai ET. Effect size guidelines for individual differences researchers. Pers. Individ. Dif. 2016; 102:74-78.
26. Preacher KJ, Kelley K. Effect size measures for mediation models: quantitative strategies for communicating indirect effects. Psychol. Methods. 2011; 16(2):93-115.
27. Knapik JJ, Steelman RA, Hoedebecke SS, Austin KG, Farina EK, Lieberman HR. Prevalence of Dietary Supplement Use by Athletes: Systematic Review and Meta-Analysis. Sports Med. 2016; 46(1):103-123.
28. Hurst P, Ring C, Kavussanu M. Evaluation of UK Athletics Clean Sport Programme in Preventing Doping in Junior Elite Athletes. Perf Enhanc Health. 2020.