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

Not Applicable

Completed

• Conditions: Dehydration
• Interventions: Other: Exercise Intervention

• Registration Number: NCT01893853
• Lead Sponsor: Pennington Biomedical Research Center

Brief Summary

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.

Detailed Description

Exercise in the heat has large effects on cardiovascular strain, the ability to regulate core body temperature, and performance because of an increase in the reliance on body fluid distribution to the skin to maintain adequate sweat rates and heat dissipation. Carbohydrate-electrolyte beverage intake during exercise in the heat may improve fluid balance and subsequent physical performance.

The participants will be assigned each arm in a randomized, counterbalanced, cross-over fashion separated by at least 2 weeks. Participants will be placed in a heated environment for the duration of the exercise intervention.

Study Timeline

• Study Start: 2012-10
• Study First Submitted: 2013-06-17
• Study First Submitted QC: 2013-07-02
• Study First Posted: 2013-07-09
• Primary Completion: 2013-10
• Study Completion: 2013-10
• Status Verified: 2022-09
• Last Update Submitted: 2022-09-13
• Last Update Posted: 2022-09-15

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Male
• Target Recruitment: 24

Inclusion Criteria

• Males aged 18-35 years
• Healthy (No uncontrolled disease)

Exclusion Criteria

• No medications that influence fluid balance
• No uncontrolled disease

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Carbohydrate-electrolyte beverage	Exercise Intervention	Commercially-available flavored beverage carbohydrate-electrolyte beverage with Exercise Intervention
Water	Exercise Intervention	Electrolyte- and mineral-free water with exercise intervention
Placebo	Exercise Intervention	Calorie- and electrolyte-free, sweetened flavored water with exercise intervention

Primary Outcome Measures

Name	Time	Method
Fluid Balance	120 minutes	Fluid balance will be determined by change in body weight during the 120 minutes steady-state exercise bout in the heat.

Secondary Outcome Measures

Name	Time	Method
Physical Performance	30 minutes	Performance during the timed exercise trial will be improved with carbohydrate-electrolyte beverage intake compared with water and placebo intake.
Rate of fluid uptake in the GI tract	30 minutes	Fluid uptake in the GI tract be assessed by D20 accumulation in the plasma.
Amount of carbohydrate oxidized	120 minutes	Carbohydrate oxidation rates will be assessed by indirect calorimetry.
Cardiovascular responses	120 minutes	Heart rate and blood pressure will be assessed during exercise.
Thermoregulatory responses	120 minutes	Body temperatures will be assessed during exercise.

Trial Locations

Locations (1)

Pennington Biomedical Research Center; 🇺🇸 Baton Rouge, Louisiana, United States