To determine the validity of a prototype patch in measuring sweating rate and sweat electrolyte concentration during moderate intensity exercise against well-established reference methods in a controlled laboratory and in field conditions.

Inclusion Criteria:

• Subject is male or female
• Subject is 15-45 years
• Subject is moderately-trained (engages in moderate-intensity, intermittent, or steady-state exercise at least 4 days per week for at least 1 hour at a time)
• Subject is capable of moderate-intensity, intermittent exercise for 1-2 hours as assessed by recent training history
• If participating in Study Session 1, 2, 3, or 4, subject has a treadmill VO2max ≥ 42 ml/kg/min if male or ≥ 38 ml/kg/min if female, as measured during the screening at the GSSI laboratory
• If participating in Study Session 1, 2, 3, or 4, subject has a normal fasting blood glucose (70-110 mg/dl), as measured during the screening at the GSSI laboratory
• If participating in Study Session 1, 2, 3, or 4, subject has a normal resting blood pressure (< 140/90 mmHg), as measured during the screening at the GSSI laboratory
• If participating in Study Session 1, 2, 3, or 4, subject has a normal resting and graded exercise EKG, as measured during the screening at the GSSI laboratory
• If participating in Study Session 1, 2, 3, or 4, willing to be shaved at patch sites
• If participating in Study Session 3 or 4, willing to undergo a nude shower by an investigator of the same sex for collection of sweat electrolytes in the whole body wash procedure
• If participating in Study Session 5 or 6, subject is a trained team-sport athlete currently participating in training/competition at IMG Academy

Exclusion Criteria:

• Subject is pregnant (self-reported)
• Subject is a smoker
• Subject has a body weight that is lighter than 80 pounds
• Subject has a known or suspected obstructive disease of the gastrointestinal tract, such as diverticulitis or inflammatory bowel disease
• Subject has a history of problems with the gag reflex
• Subject has not had previous gastrointestinal surgery
• Subject has problems with swallowing
• Subject is planning to have an MRI scan during the time that the CorTemp™ Core Body Temperature Sensor is in the body
• Subject has slow movement of the gastrointestinal tract
• Subject has a cardiac pacemaker or other implanted electronic device
• Subject has asthma or other condition in which breathing can become difficult/labored during exercise (applies to Study Session 1-4 only)
• Subject is allergic to adhesives
• Subject is currently taking a medication or oral supplement that could interfere with study results
• Subject has a condition 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 has been enrolled into a PepsiCo-sponsored study within the past six months
• Subject has been enrolled into a clinical trial at a laboratory or clinic other than PepsiCo within the past 30 days
• 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 products. 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.