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Completed

NCT Number: NCT01974986

Rehydration Following Exercise-Induced Dehydration

Athletes participating in multiple training sessions a day can be at increased risk of suboptimal hydration and heat illness during their second training session, especially when the environment is hot and humid. With the exception of the absolute volume of water delivered by a rehydration beverage, characteristics of the beverage consumed play a role in the recovery and completeness of rehydration. The amount of sodium in the beverage has been shown to be a primary factor in rehydration. Recently, an effect of the carbohydrate concentration of the beverage was been reported, with its effects mediated by the renal system in response to elevated serum insulin. The purpose of this study is to compare sodium and carbohydrate effects on rehydration and recovery.

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Key information

Conditions

Dehydration Related to Exercise Behavior Dehydration Metabolic Diseases Motor Activity Nutritional and Metabolic Diseases Pathologic Processes Pathological Conditions, Signs and Symptoms Water-Electrolyte Imbalance

Age range

18 year–35 year

Sex eligibility

Male

Study type

Interventional

Phase

Not applicable

Primary location

University of Illinois

Chicago, Illinois, 60608, United States

About this study

The effectiveness of beverage composition will be evaluated by modifying the sodium content and carbohydrate content of the beverage. Hypothesis: Completeness of rehydration will be greater in the beverage with higher sodium concentration. It is also hypothesized that electrolyte-carbohydrate beverages will promote rehydration that exceeds that of consuming placebo (water). Using a randomized balanced-treatment crossover design, physically trained males (18-35 yrs) will participate in intermittent exercise for 85 to 100 minutes in three experimental trials of variable intensity training in the heat (30 +/-3 C) followed by a rehydration-recovery period. Exercise will be done at varying intensities (intermittent intervals) ranging from 50% to nearly 100% of maximum oxygen uptake (max VO2) determined prior to the experimental trials. During the 85 to 100 min of exercise, no fluids will be given during the trial to elicit an acute reduction in body mass of approximately 2.5 to 3% (standardized for each subject). Following exercise, 100% of the volume of fluid lost will be replaced with one of the beverages. Beverages will be ingested in six aliquots over a 1-hr period given at the end of the trial. Retention of fluid will be calculated by measuring volume of urine lost at 30, 60, 135, and 210 min following ingestion of the rehydration beverage. The primary outcome variable is the percentage of fluid retained, i.e., the difference between volume ingested and cumulative urine produced in 3.5 h as a percentage of volume ingested. Body mass, urine specific gravity, total body water, and ratings of vigor and affect will be assessed prior to exercise, after exercise in a state of dehydration, and at 210 min post-exercise following rehydration. A one-way ANOVA will be used to test the hypothesis for rehydration, the primary outcome variable.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Male, age 18-35 y, physically fit, and regularly undergoing exercise training particularly but not exclusively in team sports.

Exclusion criteria

  • "Yes" on PAR-Q survey, symptoms or signs of exercise intolerance, VO2 max <50 mL/kg/min, smoker

Treatment and study plan

Water with flavoring and non-nutritive sweetener.

Other

A volume of fluid (water) was given after exercise to return each subject's body mass (to euhydration).

High-Na low-CHO beverage

Other

A volume of fluid (high-Na, low-CHO) was given after exercise to return each subject's body mass (to euhydration).

Low-Na high-CHO beverage

Other

A volume of fluid (low-Na, high-CHO) was given after exercise to return each subject's body mass (to euhydration).

Primary outcomes

  1. Rehydration

    Time frame: 8 hours

    Fluid retained to rehydrate the body as a percentage of volume of beverage ingested.

Secondary outcomes

  1. Body weight

    Time frame: 8 hours

    Change in body mass from the start of data collection.

Other outcomes

  1. Total body water

    Time frame: 8 hours

    Change in estimated total body water from the start of data collection.

Sponsors and collaborators

Lead sponsor

University of Illinois at Chicago

Other

Collaborators

  • Abbott Nutrition

Registry information

Official study title

Rehydration Following Exercise-Induced Dehydration: Beverage Formula Effects in Team Sport Athletes

Important dates

Study start
2013
Primary completion
2015
Study completion
2016
First posted
Nov 4, 2013
Registry last updated
Jun 2, 2016

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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