COVID-19 shutdown prevented study enrollment. Staff was subsequently lost to execute trial aims.

Kona Deep is bottled water extracted from a depth of 3000 feet off the cost of Kona, Hawaii. Kona Deep claims that this unique source provides water that is "naturally free of pathogens, chemicals and pollutants and rich in nutrients and minerals that are readily absorbed by the body". The investigators wish to examine Kona Deep's claim that this water is "beneficial to the human body" by testing the impact of drinking Kona Deep on exercise performance and recovery. Subjects will be exercised to a safe level of dehydration and then will be rehydrated with Kona Deep water, or commercially available bottled spring water or Gatorade as controls. Subjects will perform a simple exercise to evaluate peak power performance. This measurement will be compared between rehydration methods for significant differences.

Exercise-induced dehydration is very common in athletes and regularly active individuals. Hypohydration, if sufficiently severe, can negatively impact physical performance and mental capacity. Development of an efficient rehydration therapy could prove beneficial in these circumstances. Multiple animal studies have shown the positive effects of desalinated deep-sea mineral water on various physiological conditions. The beneficial effects of deep-sea mineral water may be attributed to its unique mineral composition, particularly magnesium, which is highly abundant in deep-sea water. The investigators wish to evaluate whether a similar response occurs in post-exercise rehydration using deep ocean water from a different source. Kona Deep is marketed as Hawaiian glacier water drawn from a depth of 915 m off the Kona coast that is naturally rich in electrolytes and nutrients, and that is free of mercury, harmful bacterial, and pollutants, making it a desired drinking water source. Accordingly, the investigators will investigate whether subjects administered Kona Deep following an exercise challenge undergo more rapid rehydration and demonstrate higher peak power production compared to subjects administered commercially available liquids. Euhydrated subjects in this study will be exposed to an exercise-challenge protocol (stationary biking) under warm conditions (30°C) to accelerate dehydration. Dehydration will be measured as a body mass loss of 3-5% (maximum exercise time will be 180 minutes). A body mass loss of 3% is the minimal amount lost during a similar exercise-dehydration protocol but where significance was still observed in exercise performance, recovery, and physiological parameters. During the post-exercise recovery period, subjects will consume one of three liquids in a volume equivalent to 1.5 times the body mass lost. Rehydration measured by salivary and urinary osmolality and exercise recovery will be measured such as oxygen consumption (VO2) at 60% estimated maximal heart rate and peak power production by contraction of the knee extensors before exercise, immediately after exercise, and after the rehydration period.

Inclusion Criteria:

• Non-smokers, BMI: 18.5-24.9, 20-25 years of age, physically active

Exclusion Criteria:

• prescription medications, BMI > 24.9

The University of Arizona (UA) will assure the timely release and sharing of data no later than the acceptance for publication of the main findings from the final dataset and will protect the rights and privacy of human subjects who participate in NIH sponsored research by redacting all identifiers and adoption of other strategies to minimize risks of unauthorized disclosure of personal identifiers in accordance with authorization and consent documents. UA will share data resulting from sponsored projects with research colleagues by depositing data on a secure web-accessible data warehouses or arranging distribution of data, reagents, protein targets, and protocols to other researchers using established mechanisms and repositories. Manuscripts will be submitted for publication in high-quality peer-reviewed journals, adhering to NIH Public Access Policy guidelines. Additionally, findings will be presented and discussed at relevant national conferences.