Dehydration | Fluid Balance During Exercise in the Heat With Water, Flavored Placebo, or a Carbohydrate-electrolyte Beverage Intake (The APEX Study)

Dehydration research study

What is the primary objective of this study?

The purpose of the APEX study is to determine whether carbohydrate-electrolyte beverage intake promotes fluid balance during exercise in the heat compared with water or placebo intake.

Who is eligible to participate?

Inclusion Criteria: - Males aged 18-35 years - Healthy (No uncontrolled disease) Exclusion Criteria: - No medications that influence fluid balance - No uncontrolled disease

Which medical condition, disease, disorder, syndrome, illness, or injury is researched?


Study Interventions

Interventions can include giving participants drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available or noninvasive approaches such as surveys, education, and interviews.

Other:Exercise InterventionExercise intervention trials will consist of a steady-state bout of exercise at ~70% VO2peak and a timed performance test on a cycle ergometer in a heated environment.

Study Arms

Research studies and clinical trials typically have two or more research arms. An arm is a group of people who receive the same treatment in the study.

WaterElectrolyte- and mineral-free water with exercise intervention

PlaceboCalorie- and electrolyte-free, sweetened flavored water with exercise intervention

Carbohydrate-electrolyte beverageCommercially-available flavored beverage carbohydrate-electrolyte beverage with Exercise Intervention

Study Status


Start Date: October 2012

Completed Date: October 2013

Phase: N/A

Type: Interventional


Primary Outcome: Fluid Balance

Secondary Outcome: Rate of fluid uptake in the GI tract

Study sponsors, principal investigator, and references

Principal Investigator: Timothy S Church, MD, MPH, PhD

Lead Sponsor: Pennington Biomedical Research Center


More information:

Latzka WA, Sawka MN, Montain SJ, Skrinar GS, Fielding RA, Matott RP, Pandolf KB. Hyperhydration: thermoregulatory effects during compensable exercise-heat stress. J Appl Physiol (1985). 1997 Sep;83(3):860-6.

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