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NCT Number: NCT06854471

Effects of Beverage Volume, Glycerol Concentration, and Sodium Concentration on Fluid Balance in Healthy Euhydrated Men and Women at Rest

The presence of certain ingredients such as sodium and glycerol can facilitate retention of the fluid consumed via renal water reabsorption. To maintain overall whole-body fluid balance, it is important that ingested fluid is retained in the body instead of losing it through urination.

The purpose of this study is to determine the effect of sodium and glycerol concentrations at various fluid intake volumes on fluid balance in healthy, euhydrated men and women.

Recruiting

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Key information

Conditions

Fluid Balance

Age range

18 year–50 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

IMG Academy/GSSI Bradenton Gatorade Sports Science Institute, Bradenton, Florida, United States

Loading trial locations.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Subject is male or female
  • If female, subject is not pregnant
  • Subject is 18-50 years of age, inclusive
  • Subject is at least recreationally active (engaged in light to moderate-intensity, intermittent, or steady-state exercise at least 3 days per week for at least 30 min at a time)
  • Subject does not smoke (or has quit for at least 6 months)
  • Subject is not taking medication that may interfere with the study (e.g., diuretics)
  • Subject has no health conditions that would interfere with the study (e.g. cardiovascular, renal, or metabolic diseases)
  • Subject is willing to avoid alcohol consumption 24 hours prior to visit(s)
  • Subject is willing to fast overnight (~8-12 hours)
  • Subject is willing to refrain from vigorous exercise for 24 hours
  • Subject is willing to eat the exact same food the day prior to each visit to the laboratory
  • Provision of written consent to participate

Exclusion criteria

  • Subject has participated in a clinical trial within the past 30 days
  • Subject has participated in any PepsiCo trial within past 6 months
  • Subject has a condition or is taking medication that the investigator believes would interfere with his/her ability to provide informed consent, comply with the study protocol, which might confound the interpretation of the study results, or put the person at undue risk
  • Subject is employed by, or has a parent, guardian, or other immediate family member employed by a company that manufactures any products that compete with any Gatorade product. If subject is unsure if a company would be considered a competitor to Gatorade, they will be asked to please let the study investigator know the name of the other company and the nature of their relationship to that company before they sign the informed consent.

Treatment and study plan

Placebo beverage, kiwi-strawberry flavor

Other

9.3.oz 3 times for a total of 28 oz over a 35 min period followed by 25 min rest until Time 0 post-dose

Electrolyte solution without glycerol beverage 1

Other

4 oz 3 times for a total of 12 oz over a 35 min period followed by 25 min rest until Time 0 post-dose. Beverage matched to placebo for color and flavor.

Electrolyte solution without glycerol beverage 2

Other

6.7 oz 3 times for a total of 20 oz over a 35 min period followed by 25 min rest until Time 0 post-dose. Beverage matched to placebo for color and flavor.

Electrolyte solution without glycerol beverage 3

Other

9.3.oz 3 times for a total of 28 oz over a 35 min period followed by 25 min rest until Time 0 post-dose. Beverage matched to placebo for color and flavor.

Electrolyte solution with glycerol beverage 1

Other

4 oz 3 times for a total of 12 oz over a 35 min period followed by 25 min rest until Time 0 post-dose. Beverage matched to placebo for color and flavor.

Electrolyte solution with glycerol beverage 2

Other

4 oz 3 times for a total of 12 oz over a 35 min period followed by 25 min rest until Time 0 post-dose. Beverage matched to placebo for color and flavor.

Electrolyte solution with glycerol beverage 3

Other

9.3.oz 3 times for a total of 28 oz over a 35 min period followed by 25 min rest until Time 0 post-dose. Beverage matched to placebo for color and flavor.

Base with glycerol, no electrolytes beverage 1

Other

4 oz 3 times for a total of 12 oz over a 35 min period followed by 25 min rest until Time 0 post-dose. Beverage matched to placebo for color and flavor.

Base with glycerol, no electrolytes beverage 2

Other

6.7 oz 3 times for a total of 20 oz over a 35 min period followed by 25 min rest until Time 0 post-dose. Beverage matched to placebo for color and flavor.

Base with glycerol, no electrolytes beverage 3

Other

9.3.oz 3 times for a total of 28 oz over a 35 min period followed by 25 min rest until Time 0 post-dose. Beverage matched to placebo for color and flavor.

Primary outcomes

  1. Fluid balance

    Time frame: Change from baseline (pre-beverage) to post-beverage Time 30, 60, 90,120, 150,180 and 210 minutes

    Calculated as change in body mass kg and %

Secondary outcomes

  1. Urine mass

    Time frame: Change from baseline (pre-beverage) to post-beverage Time 30, 60, 90,120, 150,180 and 210 minutes

    (g)

  2. Urine specific gravity

    Time frame: Change from baseline (pre-beverage) to post-beverage Time 30, 60, 90,120, 150,180 and 210 minutes

    (au)

  3. Urine osmolality

    Time frame: Change from baseline (pre-beverage) to post-beverage Time 30, 60, 90,120, 150,180 and 210 minutes

    (mosmol/kg)

  4. Whole blood hematocrit

    Time frame: Change from baseline (pre-beverage) to post-beverage Time 30, 90,150 and 210 minutes

    (%)

  5. Whole blood hemoglobin concentration

    Time frame: Change from baseline (pre-beverage) to post-beverage Time 30, 90,150 and 210 minutes

    (g/dl)

  6. Serum sodium concentration

    Time frame: Change from baseline (pre-beverage) to post-beverage Time 30, 90,150 and 210 minutes

    (mmol/L)

  7. Serum potassium concentration

    Time frame: Change from baseline (pre-beverage) to post-beverage Time 30, 90,150 and 210 minutes

    (mmol/L)

  8. Serum chloride concentration (mmol/L)

    Time frame: Change from baseline (pre-beverage) to post-beverage Time 30, 90,150 and 210 minutes

    (mmol/L)

  9. Serum glucose concentration

    Time frame: Change from baseline (pre-beverage) to post-beverage Time 30, 90,150 and 210 minutes

    (mg/dl)

  10. Serum glycerol concentration

    Time frame: Change from baseline (pre-beverage) to post-beverage Time 30, 90,150 and 210 minutes

    (mmol/L)

  11. Serum copeptin concentration

    Time frame: Change from baseline (pre-beverage) to post-beverage Time 30, 90,150 and 210 minutes

    (pmol/L)

  12. Serum osmolality

    Time frame: Change from baseline (pre-beverage) to post-beverage Time 30, 90,150 and 210 minutes

    (mosmol/kg)

  13. Blood pressure

    Time frame: Change from baseline (pre-beverage) to post-beverage Time 30, 60, 90,120, 150,180 and 210 minutes

    (systolic/diastolic) (mmHg)

  14. Heart rate

    Time frame: Change from baseline (pre-beverage) to post-beverage Time 30, 60, 90,120, 150,180 and 210 minutes

    (bpm)

  15. Subjective measures of gastrointestinal discomfort and headache (VAS)

    Time frame: Change from baseline (pre-beverage) to post-beverage Time 30, 60, 90,120, 150,180 and 210 minutes

    Rated on a 100 point scale from none to severe for headache, lightheaded, stomach upset, nausea, burping, stomach bloating, abdominal discomfort, stomach fullness, vomiting, diarrhea).

  16. Menstrual categorization

    Time frame: Screening visit

    Current status (e.g., contraception, regular periods or not, etc.)

  17. Adverse Events

    Time frame: From Screening (Visit 1) through the fifth and final beverage testing day (Visit 6)

    Documented changes in health and symptoms

Study contacts

Contact information is provided by the study sponsor or research team.

Lindsay Baker, PhD

CONTACT

[email protected]

800.884.2867

Sponsors and collaborators

Lead sponsor

PepsiCo Global R&D

Industry

Registry information

Important dates

Study start
2025
Primary completion
2025
Study completion
2025
First posted
Mar 3, 2025
Registry last updated
Jul 17, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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