NCT07520344 · PepsiCo Global R&D
Wearable Photoplethysmography for Non-invasive Hydration Assessment
What this study is about
Hydration status during exercise is often determined by measuring body mass change, fluid intake and urine output. However, obtaining these measurements can be an invasive, time-consuming process. Hydration status may be detectable by analyzing blood flow patterns of the superficial (just under the skin) blood vessels.
View original scientific description
Hydration status during exercise is often determined by measuring body mass change, fluid intake and urine output. However, obtaining these measurements can be an invasive, time-consuming process. Hydration status may be detectable by analyzing blood flow patterns of the superficial (just under the skin) blood vessels. Wearable devices are now abundant among the general population, and despite attempts from several groups, a hydration status metric based on noninvasive wearable device metrics has not been developed. With wearables, a light source connected to an optical sensor transmits and reflects light through the body. The light sensor detects absorption of the light based on wavelength measurements of the detected light. Absorption of specific wavelengths of light energy is dependent upon the amount of oxygenated blood in the vessels. When the vessels expand and relax, the amount of blood volume in the observed tissue increases and decreases potentially causing a shift in the photoplethysmography (PPG) wave detected by the wearable. The shift in the shape of the PPG wave may be detected in a way that indicates the relative change in tissue hydration levels. However, to our knowledge, no wrist worn device that utilizes PPG has been successfully able to predict hydration status. Therefore, this study aims to utilize photoplethysmography (PPG) technology in a wearable device to accomplish this approach to hydration monitoring.
Interventions
OTHER
Exercise
Perform stationary cycling exercise in the laboratory for 2 30- minute bouts at a standardized exercise intensity (wattage) that elicits 50-80% heart rate max determined by equation (208-(70% of age))
Primary outcome measures
Wearable Sensr Data
Time frame: Continuous data collection over 24 hours from start of exercise trial through completion of Day 2 measurements.
photoplethysmogram (PPG) waveform data- optical signals obtained from photoplethysmography, which measure blood volume changes in the microvascular bed of tissue.
Body Mass Change
Time frame: Change in body mass during 60 min exercise bout and over 24 hours from baseline
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Study subject is 18-45 years of age, inclusive
- Subject is male or female
- If female, subject is not pregnant, planning to get pregnant, or currently breast feeding
- Subject is willing to avoid alcohol consumption 24 hours prior to visit(s)
- Able to speak, write, and read English
- Provision of written consent to participate
- Subject is not taking medication that may interfere with the study, as indicated on the general health questionnaire (GHQ)
- Subject has no health conditions that would prevent completion of the trial, as indicated on the GHQ
- Subject is willing to fast overnight (no food or beverage, only water, \~8- 10 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 testing site
- Subject is willing to undergo fluid restriction to induce dehydration
- Subject is willing to wear a wrist worn wearable device for the duration of the study
Exclusion criteria
- Subject has participated or currently enrolled in a clinical trial within the past 30 days
- Subject has participated in any PepsiCo trial within the past 3 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, as indicated on the GHQ
- 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.
- Subject has a health condition or is taking medication that can be worsened by fluid restriction, as indicated on the GHQ
Where
- Frisco, Texas
- Plano, Texas
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Apr 9, 2026 · Source of record for eligibility and locations