The descriptive cross-sectional study used a validated questionnaire to collect data from 106 middle-distance runners, ranging from regional competitors to international athletes.
The authors from Poland and Spain concluded: “Higher-level athletes consume SS that have greater scientific evidence.
“On the other hand, although the most commonly consumed SS have evidence for the performance or health of middle-distance runners, runners should improve both their sources of information and their places of purchase.”
Middle-distance running events require significant contributions of both aerobic and anaerobic metabolism from the athlete.
Middle-distance runners engage in a diverse range of training intensities, encompassing low to very-high-intensity sessions, and elite middle-distance runners develop capacities similar to both long-distance runners and sprinters, with enhanced aerobic and anaerobic capabilities.
Athletes often use SS for their notable worthwhile performance enhancement, and in middle-distance races, the supplements that have shown the most evidence of improving performance are caffeine, β-Alanine, and sodium bicarbonate.
However, previous research found that vitamins, minerals, and amino acids are more popularly consumed.
Although SS have shown health and performance benefits, athletes’ knowledge of them reportedly can be limited, and it has been shown that the use of some SS with less scientific evidence is greater than those with higher levels of supporting research.
Supplements can be classified into four groups using an “ABCD” system, based on scientific evidence for determining whether a product is safe, permitted, and effective in improving performance or health:
Group A supplements hold solid scientific evidence in specific situations under established protocols; Group B supplements have components with emerging evidence that should be used in research or clinical settings; Group C supplements have limited evidence and effects on performance; and Group D supplements are prohibited products or those with a high risk of contamination by doping substances.
Previous research has shown that motivators for SS consumption can be credited to "unqualified individuals”, such as friends and teammates.
The authors of the new study explain that there is a lack of research analysing supplementation patterns in athletes, particularly in middle-distance runners.
They state: “Thus, the objective of this research is to know the supplementation trends in those athletes with respect to their level and gender.
“On the other hand, it aims to assess whether the SS taken by middle-distance runners are those with the most scientific evidence, thus reducing the existing gap in the literature.”
A total of 106 middle-distance runners (800–1500 m) participated, of which 74 were men and 32 were women (gender assigned at birth).
Of the total sample, 85.85% responded that they consumed SS, with no statistical difference found regarding the level of competition or sex of the athletes.
Concerning the level of competition, differences were observed in the total consumption of SS (p = 0.012), as well as in that of medical supplements (p = 0.005).
Differences were also observed between the sexes in the consumption of medical supplements (p = 0.002) and group C supplements (p = 0.029).
The authors conclude that higher-level athletes consumed more supplements, especially medical ones, which they suggest indicates a focus on health maintenance and recovery.
The most-consumed SS was found to be caffeine, and the second most consumed were sports drinks and sports bars, both categorised as ‘Group A’ SS. Isolated protein was reportedly third most popular amongst the participants.
Athletes reported that those who encouraged the use of SS were mainly coaches (37.74%), followed by dieticians–nutritionists (26.42%), teammates (21.70%), or physicians (16.04%).
Some other people and sources recommended its use such as friends and the internet (8.49%) or social network profiles (4.72%).
The authors add: “It is important to mention that, although a large part of the SS consumed by middle-distance runners in this study belong to group A, it is also observed that there is still a fairly large consumption of supplements with little or no scientific evidence (groups B and C).
“This has also been observed in other sports, so it is important that athletes use reliable sources of information when deciding which supplements to consume.”
They also note that the study had its limitations, including that while the sample was larger than that of previous studies, greater participation of international athletes is necessary.
Additionally, the nature of the self-reporting questionnaire could lead to errors in the number or type of supplements.
“It is necessary to compare and have the support of different federations or institutions worldwide to check if the consumption is similar depending on the competitive level or gender,” they conclude.
“Are Supplements Consumed by Middle-Distance Runners Evidence-Based? A Comparative Study between Level of Competition and Sex”
Authors: Asier Del Arco, Aitor Martinez Aguirre-Betolaza, Ewa Malchrowicz-Mośko, Anna Gogojewicz and Arkaitz Castañeda-Babarro