IOC consensus statement: dietary supplements and the high-performance athlete

Abstract

Nutrition usually makes a small but potentially valuable contribution to successful performance in elite athletes, and dietary supplements can make a minor contribution to this nutrition programme. Nonetheless, supplement use is widespread at all levels of sport. Products described as supplements target different issues, including (1) the management of micronutrient deficiencies, (2) supply of convenient forms of energy and macronutrients, and (3) provision of direct benefits to performance or (4) indirect benefits such as supporting intense training regimens. The appropriate use of some supplements can benefit the athlete, but others may harm the athlete’s health, performance, and/or livelihood and reputation (if an antidoping rule violation results). A complete nutritional assessment should be undertaken before decisions regarding supplement use are made. Supplements claiming to directly or indirectly enhance performance are typically the largest group of products marketed to athletes, but only a few (including caffeine, creatine, specific buffering agents and nitrate) have good evidence of benefits. However, responses are affected by the scenario of use and may vary widely between individuals because of factors that include genetics, the microbiome and habitual diet. Supplements intended to enhance performance should be thoroughly trialled in training or simulated competition before being used in competition. Inadvertent ingestion of substances prohibited under the antidoping codes that govern elite sport is a known risk of taking some supplements. Protection of the athlete’s health and awareness of the potential for harm must be paramount; expert professional opinion and assistance is strongly advised before an athlete embarks on supplement use.

Inconsistency in the Ergogenic Effect of Caffeine in Athletes Who Regularly Consume Caffeine: Is It Due to the Disparity in the Criteria That Defines Habitual Caffeine Intake?

“…In addition, the threshold of daily caffeine intake used to correctly categorize an individual/athlete as a habitual caffeine user has not been properly established. We conclude that the general guidelines for acute caffeine intake [3], which are based on individuals with no habituation to caffeine, are not applicable to habitual caffeine consumers because of the existence of tolerance to caffeine ergogenicity [15,16]. Before creating new caffeine guidelines for habitual users, the establishment of common and unified norms to classify individuals who ingest caffeine on a daily basis is required.…”

“…Nowadays, caffeine is the most popular psychoactive substance in the world and data on urine caffeine concentration suggests that it is widely used by athletes before competition to enhance physical and mental fitness [1,2]. The research supporting the ergogenic effects of acute caffeine intake in a variety of sporting disciplines and exercise scenarios is extensive, and the International Olympic Committee has recently classified caffeine as a substance that enhances performance based on this strong scientific evidence [3]. However, most of the studies supporting this claim have used samples of athletes who do not consume caffeine on a regular basis and with caffeine intake withdrawal prior to the experiments, in an attempt to enhance the margin of action of this substance on physical performance [4,5].…”

“…Only eight studies were conducted on participants with a daily caffeine intake between 100 and 299 mg/day (Table 1). Investigations within this range of daily caffeine intake are particularly interesting because this might represent an intake of~3 mg/kg of caffeine per day for athletes with a body mass between 40 and 100 kg, whereas this is typically considered as the minimal dose that gives an ergogenic effect in naïve/low caffeine consumers [3]. Studies in which participants ingested caffeine for several days to habituate them to caffeine were included in this analysis.…”

The Physiological Effects of Amino Acids Arginine and Citrulline: Is There a Basis for Development of a Beverage to Promote Endurance Performance? A Narrative Review of Orally Administered Supplements

“…Supplementation for competitive or recreational use is widespread in today's society, and it has become increasingly popular in recent years [1]. Results of a survey in 2016, indicated around 50% of athletes are taking supplements regularly, although this does not capture the 'irregular' supplement users, or what a particular individual might define as a 'supplement' [30,31]. While the prevalence of supplementation has not necessarily increased over the period of a few years, a study by Shaw et al (2016) observed a greater amount of supplements being used within the same populations [30].…”

“…Several institutions, such as the Australian Institute of Sport (AIS), provide a framework of supplement classifications, which includes an educational tool to rank sports foods and supplements (and their 'functional' ingredients) according to their scientific evidence and safety, allowing a practical contribution to an individual's performance goals [32]. In 2018, the International Olympic Committee (IOC) released a consensus statement on supplements and the high-performance athlete, indicating supplement use varied between different sports or activities [31]. This also increased with age, the level of training or performance, and was strongly influenced by perceived cultural and social norms [31].…”