The Impact of Buoy on Hydration Status of Active Men and Women
Authors: Boyd-Shiwarski Cary , Ray Evan , Subramanian Harikesh , Zharichenko Nicole , Monroe Amy , Mahajan Aman 
Published: October 2024

Background

Hypo-hydration is a major health concern that affects performance and is associated with increasing morbidity and growing health care costs. There is an emerging interest in optimum hydration and identifying how factors such as ingestion rate and beverage composition affect hydration. This study examined three beverages with varying ingestion rates and measured markers of hydration.

Methods

Thirty healthy, active participants between ages 18-45 years were given three different beverages on three separate days. The beverages were of identical volumes (1 Liter), but differed in the rate of ingestion, carbohydrate content and electrolyte content. Beverage 1 (Buoy, San Diego, CA) and water-alone were both consumed at a metered rate of one liter over four hours, whereas Beverage 2 was used as a positive control and consumed at a bolus rate of one liter in 30 minutes.

Findings

After six hours Beverage 1 significantly improved markers of hydration compared to water-alone or Beverage 2. Beverage 1 decreased cumulative urine output vs water-alone by 32% (absolute difference -0.33L; CI ± -0.16 to -0.51) and vs Beverage 2 by 26% (absolute difference - 0.26L; CI ± -0.13 to -0.38). Beverage 1 increased the beverage hydration index vs water-alone by 64% (absolute difference +0.64L; CI ± 0.36 to 0.92) and vs Beverage 2 by 48% (absolute difference +0.53L; CI ± 0.30 to 0.76)

Interpretation

Beverage 1 is superior to water-alone at improving hydration when ingested at similar rates. Moreover, metered ingestion of Beverage 1 improved hydration compared to a bolus ingestion of Beverage 2, this could be due to the dissimilar ingestion rates and/or beverage composition.

RESEARCH IN CONTEXT

Despite the overwhelming number of commercial hydration beverages on the market, there are only a very limited number of studies that address whether these beverages are actually effective at improving hydration. Using PubMed and Google Scholar using the search term “Beverage Hydration Index” with the search date from 2016-2024 (2016 was when the Beverage Hydration Index was established) we found less than 10 articles on this topic that used the beverage hydration index to assess the efficacy of popular beverages and supplements, and none of them have previously evaluated the efficacy of Beverage 1 (Buoy). Additionally, only one other study assessed how that rate of beverage ingestion can influence the beverage hydration index. This current study has found Beverage 1 increased the beverage hydration index vs water-alone by 64% (absolute difference +0.64L; CI ± 0.36 to 0.92). We propose that Beverage 1 increases the beverage hydration index due to its abundance of electrolytes including sodium and chloride, as it does not contain carbohydrates, protein, or artificial sweeteners that are common in other commercial hydration beverages. Identifying beverages that improve hydration compared to water-alone can play an important role in preventing severe hypohydration and dehydration, including renal failure, seizures, arrythmia, and altered mental status. It has been estimated that over half a million hospitalizations per year are due to dehydration with a cost of over 5.5 billion United States dollars(1). Thus, there are both clinical and economic reasons to identify simple, cost-effective methods to promote euhydration.