Nutritional Supplements Usage by Portuguese Athletes

Abstract

In this study, we determined the prevalence of nutritional supplements (NS) usage, the type of supplements used, the reasons for usage, and the source of nutritional advice among Portuguese athletes. Two hundred ninety-two athletes (68 % male, 12 - 37 years old) from 13 national sports federations completed a questionnaire that sought information on socio-demographics, sports data, and NS usage. Most athletes (66 %) consumed NS, with a median consumption of 4 supplements per athlete. The most popular supplements included multivitamins/minerals (67 %), sport drinks (62 %), and magnesium (53 %). Significant differences for the type of NS consumed were found between gender and age groups and the number of weekly training hours. Most athletes used NS to accelerate recovery (63 %), improve sports performance (62 %), and have more energy/reduce fatigue (60 %). Athletes sought advice on supplementation mainly from physicians (56 %) and coaches (46 %). Age and gender were found to influence reasons for use and the source of information. Reasons for NS usage were supported scientifically in some cases (e. g., muscle gain upon protein supplementation), but others did not have a scientific basis (e. g., use of glutamine and magnesium). Given the high percentage of NS users, there is an urgent need to provide athletes with education and access to scientific and unbiased information, so that athletes can make assertive and rational choices about the utilization of these products.

6 Nutritional Supplements

“…There are different definitions of the concept "supplement" and which supplements includes 1,2,6,7,12 . According to the Dietary Supplement Health and Education Act of 1994, the term "dietary supplement" includes any product orally consumed (except tobacco) to supplement someone's diet that contains one or more dietary ingredients.…”

“…However, the list of supplements with scientific evidence supporting its efficacy and safety is short 1,2,4,10,11 , and, unlike medication, these products do not undergo rigorous control criteria or require prior approval of regulatory authorities, which could be an alarming situation for athletes 1,6,9,10 . About 25% of supplements are contaminated with substances prohibited by World Anti-Doping Agency (WADA, 2016) and the main contaminant are anabolic steroids 2,7 . This presents a potential risk to the athlete's health and a negative impact in the athlete's career since he may be suspended for accusing positive in an anti-doping control test 1,2,4,6,10,11 .…”

“…About 25% of supplements are contaminated with substances prohibited by World Anti-Doping Agency (WADA, 2016) and the main contaminant are anabolic steroids 2,7 . This presents a potential risk to the athlete's health and a negative impact in the athlete's career since he may be suspended for accusing positive in an anti-doping control test 1,2,4,6,10,11 .…”

“…Its use is more prevalent than in general population, and is gaining popularity in various sports [1][2][3][4][5][6][7][8][9] . The international prevalence of supplements usage varies between 37% and 89% 10 , more frequently in older and elite athletes 2,3,5,7,10,11 , being associated with increased physical demands at the highest level of physical training and also to continue to improve athletic performance 12 .…”

“…These products may contain vitamins, minerals, herbs or botanicals, amino acids and substances like enzymes, organ tissues, glandular and metabolites, extracts or concentrates under the form of tablets, capsules, liquids, powders, bars, soft gels or caps gels 2,3,7,[12][13][14] . Therefore, there is a range of supplements available with different and specific objectives 1 .…”