Effect of Glycerol-Electrolyte Beverages on Fluid Balance in Healthy Euhydrated Men and Women at Rest

The objective of this study is to determine the effect of consumption of drinks with varying amounts of glycerol and electrolytes on fluid balance at rest.

Study Overview

• Status: Completed
• Conditions: Hydration
• Intervention / Treatment: Other: Beverage. Incomplete block where each participant will complete 3 of the 6 possible glycerol-sodium blends in random order.

• Study Type: Interventional
• Enrollment (Actual): 37
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • New York
    • Valhalla, New York, United States, 10595
      • PepsiCo R&D, Gatorade Sports Science Institute

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Subject is male or female
• If female, subject is not pregnant
• Subject is 18-50 years of age, inclusive
• You are 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 as indicated on the general health questionnaire (GHQ), 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
• Able to speak, write, and read English
• 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.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Quadruple

Number of Arms

6

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Control; No sodium, No glycerol	Other: Beverage. Incomplete block where each participant will complete 3 of the 6 possible glycerol-sodium blends in random order.; 9.3 oz (273 ml) aliquot of one of the study beverages every 15 min for a total of 28 oz (828 ml) over a 45-min period, followed by 15 min of rest. Flavored water matched for sweetness, color. flavor, but cannot be matched for saltiness. All sodium-containing drinks will include a base blend of other electrolytes (potassium 15 mmol/L, magnesium 8 mmol/L, and calcium 5 mmol/L).
Experimental: Sodium only group 1; 55 mmol/L sodium	Other: Beverage. Incomplete block where each participant will complete 3 of the 6 possible glycerol-sodium blends in random order.; 9.3 oz (273 ml) aliquot of one of the study beverages every 15 min for a total of 28 oz (828 ml) over a 45-min period, followed by 15 min of rest. Flavored water matched for sweetness, color. flavor, but cannot be matched for saltiness. All sodium-containing drinks will include a base blend of other electrolytes (potassium 15 mmol/L, magnesium 8 mmol/L, and calcium 5 mmol/L).
Experimental: Glycerol only; 4.6% glycerol	Other: Beverage. Incomplete block where each participant will complete 3 of the 6 possible glycerol-sodium blends in random order.; 9.3 oz (273 ml) aliquot of one of the study beverages every 15 min for a total of 28 oz (828 ml) over a 45-min period, followed by 15 min of rest. Flavored water matched for sweetness, color. flavor, but cannot be matched for saltiness. All sodium-containing drinks will include a base blend of other electrolytes (potassium 15 mmol/L, magnesium 8 mmol/L, and calcium 5 mmol/L).
Experimental: Sodium and Glycerol group 1; 55 mmol/L sodium and 4.6% glycerol	Other: Beverage. Incomplete block where each participant will complete 3 of the 6 possible glycerol-sodium blends in random order.; 9.3 oz (273 ml) aliquot of one of the study beverages every 15 min for a total of 28 oz (828 ml) over a 45-min period, followed by 15 min of rest. Flavored water matched for sweetness, color. flavor, but cannot be matched for saltiness. All sodium-containing drinks will include a base blend of other electrolytes (potassium 15 mmol/L, magnesium 8 mmol/L, and calcium 5 mmol/L).
Experimental: Sodium only group 2; 27.5 mmol/L sodium	Other: Beverage. Incomplete block where each participant will complete 3 of the 6 possible glycerol-sodium blends in random order.; 9.3 oz (273 ml) aliquot of one of the study beverages every 15 min for a total of 28 oz (828 ml) over a 45-min period, followed by 15 min of rest. Flavored water matched for sweetness, color. flavor, but cannot be matched for saltiness. All sodium-containing drinks will include a base blend of other electrolytes (potassium 15 mmol/L, magnesium 8 mmol/L, and calcium 5 mmol/L).
Experimental: Sodium and Glycerol group 2; 27.5 mmol/L sodium and 2.3% glycerol	Other: Beverage. Incomplete block where each participant will complete 3 of the 6 possible glycerol-sodium blends in random order.; 9.3 oz (273 ml) aliquot of one of the study beverages every 15 min for a total of 28 oz (828 ml) over a 45-min period, followed by 15 min of rest. Flavored water matched for sweetness, color. flavor, but cannot be matched for saltiness. All sodium-containing drinks will include a base blend of other electrolytes (potassium 15 mmol/L, magnesium 8 mmol/L, and calcium 5 mmol/L).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Fluid balance	Change in body mass to the nearest 0.005 kilogram (kg) using a platform scale	Change from baseline (pre-beverage) to post-beverage Time 0, 30, 60, 90,120 and 180 minutes

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Fluid retention	As a percent (%)	Change from baseline (pre-beverage) to post-beverage Time 0, 30, 60, 90,120 and 180 minutes
Urine mass	By urine mass scale in grams (g)	Change from baseline (pre-beverage) to post-beverage Time 0, 30, 60, 90, 120 and 180 minutes
Urine specific gravity	By USG digital pen refractometer	Change from baseline (pre-beverage) to post-beverage Time 0, 30, 60, 90,120 and 180 minutes
Blood sodium	By iSTAT Blood Electrolyte and Chemistry Analyzer (CG8+ cartridge) in mmol/L	Change from baseline (pre-beverage) to post-beverage Time 0, 60 min, 120 min and 180 minutes
Blood glucose	Glucometer for point of care test in mg/dL	Screening visit only
Blood glucose	By iSTAT Blood Electrolyte and Chemistry Analyzer (CG8+ cartridge) in mg/dL	Change from baseline (pre-beverage) to post-beverage Time 0, 60 min, 120 min and 180 minutes
Percent change in plasma volume	Calculated from hematocrit and hemoglobin concentration	Change from baseline (pre-beverage) to post-beverage Time 0, 60 min, 120 min and 180 minutes
Serum glycerol concentration	By Sigma Aldrich glycerol assay kit in mmol/L	Change from baseline (pre-beverage) to post-beverage Time 0, 60 min, 120 min and 180 minutes
Blood pressure	mmHg by automatic sphygmomanometer	Change from baseline (pre-beverage) to post-beverage Time 0, 30, 60, 90, 120 and 180 minutes
Heart rate	Beats per minute (bpm) by heart rate monitor	Change from baseline (pre-beverage) to post-beverage Time 0, 30, 60, 90, 120 and 180 minutes
Subjective measures of gastrointestinal discomfort and headache	Visual Analog Scale (VAS) symptom rating of how you feel right now by placing a slash along a 100 millimeter (mm) vertical line anchored from 0 mm (None) to 100 mm (Severe). Fewer symptoms and lower numbers are better.	Change from baseline (pre-beverage) to post-beverage Time 0, 30, 60, 90, 120 and 180 minutes
Menstrual cycle phase	Date of last menstrual period by self-report of female participant	Female participants log menstrual flow throughout study participation. The three study sessions (2-45 days apart) are scheduled to avoid menses and can be completed in the same menstrual cycle, or in 3 different cycles (3 different months) if needed.

Collaborators and Investigators

• Sponsor: PepsiCo Global R&D
• Investigators: Principal Investigator: Lindsay Baker, PhD, PepsiCo, Inc. Sports Science

Study record dates

Study Major Dates

• Study Start (Actual): January 8, 2024
• Primary Completion (Actual): June 28, 2024
• Study Completion (Actual): June 28, 2024

Study Registration Dates

• First Submitted: December 8, 2023
• First Submitted That Met QC Criteria: December 28, 2023
• First Posted (Actual): December 29, 2023

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: January 2, 2025
• Last Verified: January 1, 2025

More Information

Terms related to this study

• Keywords: fluid balance; hydration; fluid retention; euhydration
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Protective Agents; Cryoprotective Agents; Glycerol
• Other Study ID Numbers: PEP-2311

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No