What is the effect of glycerol-, sodium- or glycerol + sodium hyperhydration on physiological and gastrointestinal outcomes during endurance running in the heat?
- Conditions
- DehydrationDiet and Nutrition - Other diet and nutrition disorders
- Registration Number
- ACTRN12621000711819
- Lead Sponsor
- Deakin University
- Brief Summary
Not available
- Detailed Description
Not available
Recruitment & Eligibility
- Status
- Completed
- Sex
- Male
- Target Recruitment
- 17
The inclusion criteria for this study is: Trained males or females, aged 18-45 years. To be classified as ‘trained’, participants must be completing running-based training equal to or greater than 3 times per week and equal to or greater than 5 hours per week as per published criteria for participants completing exercise-based studies. Naturally menstruating females will need to be classified as ‘eumenorrheic’ (i.e., having 9 or more menstrual cycles in the last 12 months and having a menstrual cycle that ranges between 21 and 35 days in length). For oral contraceptive users. Females using an oral contraceptive will need to have been using the same oral contraceptive for the previous three months.
Exclusion criteria also includes any abnormal renal function, use of diuretics or creatine in the previous eight weeks as these factors can affect the body’s fluid retention capability. Participants that have previously suffered from heat illness and those that have an impairment that affects thermoregulation will also be excluded. Participants will be excluded if they answer ‘Yes’ to any of the first six questions in stage one of the attached Exercise and Sport Science Australia (ESSA) pre-screening tool. Participants will also complete stage 2 of the ESSA pre-screening tool, those that have multiple (equal to or greater than 2) risk factors, will be asked to seek medical advice before participating in this project. Participants must not have sustained a lower limb injury in the last six months and have no current injury that will impact their ability to complete the exercise protocol in the study. Participants will also be excluded if they have a history of migraines, chronic headaches, liver disease as it is recommended that these populations avoid glycerol ingestion. Participants who are allergic to the nutritional aids to be used in the study (e.g., glycerol and/or sodium chloride) will also be excluded.
Study & Design
- Study Type
- Interventional
- Study Design
- Not specified
- Primary Outcome Measures
Name Time Method Fluid retention: calculated as the total amount of fluid ingested minus the total amount of urine produced.[ Fluid retention will be calculated at minute 180 of the trial.]
- Secondary Outcome Measures
Name Time Method Gastrointestinal symptoms will be measured using a questionnaire devised from a modified VAS. Participants will rate the severity of upper and lower gastrointestinal symptoms from 0-10. This is a composite secondary outcome. [ Gastrointestinal symptoms will be continuously monitored throughout the trial at baseline (min 0), min 20, 40, 60, 80, 100, 120, 140, 160, 180. ]