Normative Data for Sweating Rate, Sweat Sodium Concentration and Sweat Sodium Loss in Female Athlete

The main objectives are to determine sweat sodium concentration [Na+], whole body sweat rate (WBSR) and rate of sweat sodium loss (RSSL) in female athletes aged 13 and above during their normal planned training session across various sports (basketball, soccer, volleyball, cheer, flag football and softball).

Study Overview

• Status: Recruiting
• Conditions: Sweat Rate
• Intervention / Treatment: Other: Sweat patch

Detailed Description

The testing procedures will follow the standardized Gatorade Sports Sciences GSSI sweat testing protocol using the absorbent sweat patch technique, to measure local sweat [Na+], which will be normalized to whole-body sweat [Na+]. Whole-body sweat rate (WBSR) will be calculated based on changes in exercise body mass, pre to post training, and adjusted for food and fluid intake, as well as urine and stool loss. The rate of sweat sodium loss (RSSL) will be determined as the product of sweat [Na+] and WBSR.

Secondary outcomes are pre-exercise hydration status measured by urine specific gravity (USG) and estimation of menstrual cycle phase collected by self-report date of last menstrual cycle.

Athletes will complete a single day of testing, unless a repeat test is requested by the team's performance staff. In this case, athletes will undergo the exact same protocol as described above.

• Study Type: Observational
• Enrollment (Estimated): 500

Contacts and Locations

• Study Contact: Name: Rebecca Randell, PhD; Phone Number: 414-520-7097; Email: rebecca.randell@pepsico.com

Study Locations

• United States
  • Illinois
    • Chicago, Illinois, United States, 60607
      • Recruiting
      • Gatorade Sports Science Institute
      • Contact: Rebecca Randell, PhD; Phone Number: 414-520-7097; Email: rebecca.randell@pepsico.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

Healthy female athletes in coach-led team sports

Description

Inclusion Criteria:

Subject is female

• Subject is 13yrs+
• Subject has been cleared for sport participation by their personal or team physician and/or coach-led practice/training.
• Subject is participating in sport on the youth/ amateur/ collegiate/professional/elite level
• If under 18, a parental/guardian consent form will be completed.

Exclusion Criteria:

• As this study is undertaken at the athletes training facility, the medical staff at the team/club will advise on who should/ should not take part.
• Subject has an allergy to adhesives (e.g., experiences rash reactions to typical adhesive bandages

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Female team sports athletes aged 13 and over; Multiple athletic teams at locations in USA and UK	Other: Sweat patch; Wear sweat patch during regular team sports practice session

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Regional sweat [Na+]	Absorbent patch technique (3M TegadermTM + Pad; 3M, St. Paul, MN; pad size 10 cm2 with an absorbent capacity of ~1.3 g) to left and right dorsal arm. An additional patch on the right scapula may be added depending on the accessibility to the sites on the body and the nature of the sport. Analyzed using a HORIBA (LAQUAtwin Na-11)	One day from start through end of a single coach-led normal training practice session. Practice duration will be dictated by coaching staff.
Whole body sweat rate (WBSR) WBSR	Pre- versus post body mass on scale, taking into account food and fluid intake, urine and stool output	One day from start through end of a single coach-led training normal training practice session. Practice duration will be dictated by coaching staff.A
Rate of sweat sodium loss (RSSL)	The rate of sodium sweat loss (RSSL) will be determined as the product of sweat [Na+] and whole-body sweat rate (WBSR)	One day from start through end of a single coach-led normal training practice session. Duration will be dictated by coaching staff.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Urine specific gravity (USG)	Unit not applicable	Pre-exercise at one coach-led normal training practice session.
Fluid intake	Weighing pre-filled bottles before and after exercise, beverage choice of water, and Gatorade, or G2	One day from start through end of a single coach-led normal training practice session. Duration will be dictated by coaching staff.
Carbohydrate intake	Grams of carbohydrate consumed through food and beverages	One day from start through end of a single coach-led normal training practice session. Duration will be dictated by coaching staff.

Collaborators and Investigators

• Sponsor: PepsiCo Global R&D
• Investigators: Principal Investigator: Rebecca Randell, PhD, PepsiCo R&D Life Sciences, Sports Science

Study record dates

Study Major Dates

• Study Start (Actual): April 22, 2025
• Primary Completion (Estimated): June 30, 2026
• Study Completion (Estimated): June 30, 2026

Study Registration Dates

• First Submitted: April 30, 2025
• First Submitted That Met QC Criteria: May 21, 2025
• First Posted (Actual): May 29, 2025

Study Record Updates

• Last Update Posted (Actual): May 29, 2025
• Last Update Submitted That Met QC Criteria: May 21, 2025
• Last Verified: May 1, 2025

More Information

Terms related to this study

• Keywords: healthy volunteer; athlete; sweat; sweat patch; sodium loss
• Other Study ID Numbers: PEP-2506

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