Hydration and Exercise Performance in Cycling

Healthy Clinical Trial

Official title:

How Does Altering the Composition of Ingested Fluids Affect Hydration Status Whilst Cycling?

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT03304197
• Other study ID #: 170614/A/01
• Status: Completed
• Phase: N/A
• Start date: September 11, 2017
• Est. completion date: June 1, 2018

Study information

• Verified date: October 2018
• Source: University of Exeter
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

This study will evaluate the effects manipulating ingested fluids can have on hydration status and cycling performance. There will be 4 different conditions.

Description:

Being dehydrated can decrease endurance exercise performance. The investigators wish to test which of three drinks is most effective at re-hydrating cyclists and if this affects performance. Subjects will undertake 4 tests: once dehydrated, once hydrated with water, once hydrated with a sports-specific drink, and once with an altered sports drink. Blood samples will be taken and expired gasses will be sampled at various time points throughout the tests for later analysis. A small amount of labelled water will be consumed with each drink, a technique which will allow us to quantify the absorption of each of the drinks.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 15
• Est. completion date: June 1, 2018
• Est. primary completion date: June 1, 2018
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 50 Years

Eligibility

Inclusion Criteria:

• Highly trained cyclists (vo2max >55 ml/kg/min, PPO (peak power output) > 4 w/kg)

• Training at least 4 times a week

• Females must be taking an oral contraceptive, or using the contraceptive implant

Exclusion Criteria:

• Recent history of musculoskeletal injury

• Diagnosed cardiovascular disease

• Regular use of nutritional supplements that may interfere with the protocol

Related Conditions & MeSH terms

• Healthy

Intervention

Dietary Supplement:
• Hypotonic
N/A: see arm description
• Isotonic
N/A: see arm description
• Placebo
N/A: see arm description

Other:
• Dehydrated
N/A: see arm description

Locations

Country	Name	City	State
United Kingdom	School of Sports and Health Sciences	Exeter	Devon

Sponsors (1)

Lead Sponsor	Collaborator
University of Exeter

Country where clinical trial is conducted

United Kingdom, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Other	Substrate utilisation	Substrate utilisation will be calculated from data collected through a metabolic cart and its software. It will be measured during the 90-minute steady-state cycle for 4 periods of 3 minutes. Carbohydrate and lipid oxidation rates will be calculated using equations by Jeukendrup & Wallis (2005).	Throughout the 90 minute steady-state cycle
Other	Plasma metabolites	A cannula will be used to draw blood from subjects at several time points. Whole blood samples will be analysed immediately for plasma glucose, plasma lactate, haemoglobin content, haematocrit and plasma volume. Remaining whole blood will be centrifuged immediately and its plasma split into aliquots and stored in a -20°C freezer. At the end of the trial, plasma samples will be moved to a -80°C freezer for later analysis for sodium, glycerol, and NEFA.	Throughout the 90 minute steady-state cycle and time-trial
Other	Heart rate	Heart rate will be measured throughout with the use of a heart rate monitor.	Throughout the 90 minute steady-state cycle and time-trial
Other	RPE (rating of perceived exertion)	RPE will be measured using the Borg Scale.	Throughout the 90 minute steady-state cycle and time-trial
Other	Core body temperature	Core temperature will be measured throughout with the use of an ingestible core-body temperature pill (HQ Inc, FL, USA).	Throughout the 90 minute steady-state cycle and time-trial
Primary	Absorption of fluid through the gut	Absorption of drinks through the gut will be measured using 2 boluses of deuterated water. This will be consumed alongside 2 of the drinks, and blood samples will be used to quantify enrichment. Total body water calculations are required to provide corrections in equations related to D2O. H218O will be consumed in order to quantify total body water: this will be provided in a single bolus before each trial.	To begin 10 minutes after the completion of the 90 minute steady-state cycle
Secondary	Work done (kJ) during 15 minute cycling time-trial	Subjects will perform a cycle ergometer protocol that has been shown to be reproducible in athletes. Subjects will complete the time trial on a Lode Excalibur cycling ergometer. Software linked to this software will record work done and power output.	Throughout the 90 minute steady-state cycle & the 15 minute time trial.