The Role of Hydration on Exercise Performance - ODIN (ODIN)

During exercise in the heat, there is a need to replenish fluids in order to avoid dehydration and decrease the risk for heat illness. What drives this urge to drink is the thirst mechanism. Following ingestion of fluids, there is an inhibition of thirst before there is a replenishing of fluids. However, there is little scientific evidence of where thirst is inhibited, if this thirst inhibition is augmented by exercise and how thirst itself influence exercise performance. Further, during rehydration studies, it is very difficult to successfully blind a subject to their drinking/hydration protocol. Previous studies that have blinded a subject to their drinking have used various methods such as intravenous fluid administration and/or nasogastric tubes. Therefore, the purpose of this research is to examine the mechanistic roles thirst inhibition plays while exercising in the heat while undergoing intravenous fluid administration. Specific attention will be directed to the cardiovascular and thermoregulatory function of the individuals. All blood, cardiovascular, thermoregulatory, and perceptual measures are shown in the diagram below.

Study Overview

• Status: Completed
• Conditions: Dehydration
• Intervention / Treatment: Other: iv fluid infusion

• Study Type: Interventional
• Enrollment (Actual): 11
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Arkansas
    • Fayetteville, Arkansas, United States, 72701
      • University of Arkansas - HPER

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 45 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Male

Description

Inclusion Criteria:

• Cycling Racing History category 3 or higher USA cycling certification
• maximal oxygen uptake >55 ml/kg/min

Exclusion Criteria:

• History of heat stroke
• Renal, cardiovascular, metabolic diseases
• Regular medication

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Euhydration - no thirst	Other: iv fluid infusion; Intravenous isotonic saline infusion
Experimental: Dehydration - no Thirst	Other: iv fluid infusion; Intravenous isotonic saline infusion

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
5km - Cycling Time Trial	Time to completion 5 km cycling time trial in the heat	2hour

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Rectal Temperature	Body core temperature at the end of the 5 km time trial	2hour

Collaborators and Investigators

• Sponsor: University of Arkansas, Fayetteville
• Investigators: Principal Investigator: Stavros A Kavouras, PhD, University of Arkansas

Study record dates

Study Major Dates

• Study Start: November 1, 2016
• Primary Completion (Actual): March 18, 2017
• Study Completion (Actual): March 18, 2017

Study Registration Dates

• First Submitted: November 30, 2016
• First Submitted That Met QC Criteria: December 1, 2016
• First Posted (Estimate): December 2, 2016

Study Record Updates

• Last Update Posted (Actual): May 31, 2017
• Last Update Submitted That Met QC Criteria: May 27, 2017
• Last Verified: May 1, 2017

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Metabolic Diseases; Water-Electrolyte Imbalance; Dehydration
• Other Study ID Numbers: 16-10-135

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
• product manufactured in and exported from the U.S.: No