Abstract
Introduction
Sodium bicarbonate is a dietary supplement that can provide small but potentially meaningful improvements in high-intensity exercise performance. Despite inclusion on the International Olympic Committee’s 2018 list of five dietary supplements known to directly improve performance, there remains a lack of information regarding the prevalence of use and athlete knowledge. The scarce data on sodium bicarbonate prevalence of use suggests that it is underutilized. The aims of this investigation were to develop and establish the content validity of a questionnaire assessing sodium bicarbonate supplementation practices and knowledge, and to quantify sodium bicarbonate’s use and knowledge among competitive athletes.
Methods
This investigation employed a survey-based, observational design and consisted of two phases. In phase one, the questionnaire was developed and sent to 11 sodium bicarbonate content experts (researchers and practitioners) for validation via the Delphi method. Content experts rated relevance, clarity, and simplicity of items/questions within the knowledge section using a 1-4 Likert scale. Content validity of each item was rated using the following formula: Content Validity Index = # of experts who gave a 3 or 4 rating / total # of experts. After receiving first-round feedback, items with a content validity score 0.78 were altered or omitted. Alterations were also made when several content experts provided similar feedback on a given item. In the second round, content experts were provided with statistics for each question, comments from all experts, and summaries of trends, before being sent the revised questionnaire for additional rating and feedback. In phase two, the validated questionnaire was shared with the target sample to gather data on sodium bicarbonate use patterns and knowledge. Eligible participants were ≥18 years old and had either regularly competed in sport or participated in at least one sporting competition during the previous 12 months.
Results
A total of 273 athletes took part in the questionnaire. Of this sample, 48 (17.6%) reported having ever supplemented with sodium bicarbonate. Of those who reported taking dietary supplements within the last 12 months with the goal of enhancing sport performance (n=206), prevalence of ever using sodium bicarbonate increased to 23.3%. Among participants with complete data on knowledge questions (n=186), correct scores averaged 33.1% (±22.6%). A one-way ANOVA revealed an effect of athlete level on knowledge scores (p0.001), with highly trained (6.5±3.6) and elite/international/world class (5.6±3.1) athletes scoring higher than recreationally active (3.7±2.9) and trained/developmental (4.4±3.3) athletes. There were no differences between men and women for knowledge (4.7±3.3 vs. 5.3±3.5, p=.230), but age was negatively correlated with knowledge (ρ=-0.33, p0.001).
Conclusion
The lifetime prevalence of sodium bicarbonate use was relatively low (less than 25%) among this sample of competing athletes, even among those reporting using sports supplements within the past 12 months. Lack of knowledge of its potential utilization among recreational/trained/developmental and older athletes is indicated as one reason why, though primary sport may also play a large role. Targeted evidence-based education may help close the knowledge-to-practice gap and promote appropriate use among regularly competing athletes in sports that may benefit.