The Role of Carbohydrate Blends and Electrolytes on Physical and Mental Performance During Cycling in the Heat (CARB-HEAT)
Study Overview
Status
Conditions
Detailed Description
EXPERIMENTAL PROTOCOL Each subject will complete five trials (one familiarization and four experimental), consisting of computer-based vigilance and reaction time tests (VIG/RT) administered before and after approximately 2 hours of cycling in a warm environment (90°F, 25-35% relative humidity). Each trial will be identical, with the only difference being the type of drink consumed during each trial. The beverages are commercially available products and are not considered investigational products under FDA regulations.
The first trial will be a familiarization trial, during which participants will complete the VIG/RT tests and cycling protocol exactly as performed in the experimental trials, but no biological samples will be collected. The remaining trials will be completed in randomized order, and the drink consumed will be:
A) Placebo (flavored water) B) GoodSport® (milk-permeate, lactose-free sports drink) C) Gatorade® (traditional sports drink) D) Low-Carb GoodSport® During the experiments, core body temperature, heart rate, skin temperature, urine samples, and expiratory gases will be collected. Blood samples will be collected using an intravenous catheter placed in an antecubital vein (see protocol figure on the next page). During the familiarization trial, no samples will be collected.
INFORMED CONSENT AND BASELINE ASSESSMENT During the initial visit, subjects will read the consent form, discuss any concerns, and have questions addressed. After signing the consent form, participants will have 20 minutes to complete the medical health history, PAR-Q questionnaire, and Ingestible Core Body Temperature Sensor Contraindication Form in person on paper.
If the volunteer is deemed eligible, height, weight, and body composition will be assessed on site using a bioelectrical impedance analyzer, and the procedure will take approximately five minutes.
Participants will then complete a standard graded exercise test (GXT) performed on a cycle ergometer. Performance data (e.g., power output) obtained from this test will be used to determine the resistance applied to the cycle ergometer during the experimental trials (description provided below). During this test, the investigators will also assess maximal oxygen uptake (VO₂max) via indirect calorimetry to evaluate aerobic capacity.
Once testing is completed, the experimental trials will be scheduled. Participants will receive a food diary form to record all food and fluid intake on the day before each trial, and dietary restrictions or allergies will be documented. Participants will be asked to replicate this intake for subsequent visits. Frozen meals will be provided for consumption as dinner before the first experimental trial. Additional meals will be provided after each experimental visit.
EXPERIMENTAL PROCESSES Subjects will ingest an individually calibrated telemetric temperature pill (e-Celsius®, France) on the evening preceding each trial to avoid interaction with fluid ingestion during testing. Subjects will report to the laboratory after at least 10 hours of fasting from food and beverages other than water, and a urine sample will be collected to verify adequate hydration status.
The urine sample will be analyzed for urine specific gravity (USG). If USG is below 1.020, indicating adequate hydration, the protocol will proceed. If USG is greater than 1.029, the trial will be canceled and rescheduled. If USG is between 1.020 and 1.029, the volunteer will consume 16 oz of water, and another urine sample will be collected within 30 minutes. The trial will be canceled and rescheduled unless USG is below 1.020 at the subsequent sample or unless the volunteer is unable to provide an additional sample.
At the start of each experimental trial, subjects will consume a light breakfast, after which body composition will be assessed using a bioelectrical impedance scale. Subjects will then complete the vigilance and reaction time tests. After completion of the tests, an intravenous catheter will be placed in an antecubital vein, and a baseline blood sample will be collected. Subjects will then void the bladder, and body weight will be measured. Once these procedures are completed, subjects will be positioned on the cycle ergometer.
Cycling Endurance Exercise Performance Each trial includes 120 minutes of cycling at 70% of VO₂max, followed by a 5-km time trial. A relative beverage volume of 15 mL/kg/h will be provided. The total beverage volume will be divided into aliquots and administered every 10 minutes during the 120-minute exercise period.
At the end of the 120-minute exercise bout, subjects will consume an additional beverage bolus before the 5-km time trial (see Figure 1 for drink timing), and another bolus will be consumed immediately before the post-exercise vigilance and reaction time (VIG/RT) tests. After completion of the tests, body composition will again be assessed using a bioelectrical impedance scale.
At regular intervals throughout the exercise protocol, body weight, blood samples, respiratory gases, and perceptual measures will be collected. See the study schematic provided below for specific measurement time points.
Study Type
Enrollment (Estimated)
Phase
- Not Applicable
Contacts and Locations
Study Contact
- Name: Sajjad Rezaei, MS
- Phone Number: 515-441-4904
- Email: srezaei8@asu.edu
Study Locations
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-
Arizona
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Phoenix, Arizona, United States, 85004
- 850 Phoenix Bioscience Core
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Principal Investigator:
- Stavros Kavouras, PhD
-
Contact:
- Shannon Wilson, PhD
- Phone Number: 602-555-5555
- Email: clinicalresearchservices@asu.edu
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-
Participation Criteria
Eligibility Criteria
Ages Eligible for Study
- Adult
Accepts Healthy Volunteers
Description
Inclusion Criteria:
- Healthy and injury free (muscle, skeletal) for greater than 2 months
- Active cyclists who train at least 3 times per week
- Body mass index (BMI) range of 18.5-30 kg/m2
- VO₂max ≥ 51 mL/kg/min for male participants
- VO₂max ≥ 45 mL/kg/min for female participants
Exclusion Criteria:
- Taking medicine influences the cardiovascular system
- non-steroidal anti-inflammatory drugs during the last week
- Cancer Diagnosis during the last 5 years
- Current Pregnancy
- History of renal disease, hypertension, obstructive gastrointestinal tract disease, disorders or impairment of the gag reflex, previous gastrointestinal surgery
- History of heat stroke
- Use of testosterone therapy
- Adults who are unable to consent (impaired decision-making capacity)
- Adults having Felinization of the esophagus
- Adults who will undergo Nuclear Magnetic Resonance (NMR) or MRI scanning within 3 days of swallowing a temperature sensitive pills
Study Plan
How is the study designed?
Design Details
- Primary Purpose: Other
- Allocation: Randomized
- Interventional Model: Crossover Assignment
- Masking: Single
Arms and Interventions
Participant Group / Arm |
Intervention / Treatment |
|---|---|
|
Placebo Comparator: Placebo
no caloric, no sodium containing flavor water
|
Flavor water
|
|
Experimental: Carbohydrate Milk Permeate sports drink
GoodSport sports drink
|
4.4% carbohydrate sports drink
|
|
Experimental: Traditional Sports drink with 6% carbs
Gatorade sports drink
|
Gatorade with 6% carbohydrate content
|
|
Experimental: Low Carbohydrate Milk Permeate sports drink
LowCarb GoodSport sports drink
|
2.2% Carbohydrate Milk Permeate sports drink
|
What is the study measuring?
Primary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
|
Time to completion of 5 kilometer cycling time trial
Time Frame: Five minutes after completion of the two-hour cycling protocol
|
cycling performance expressed as time to completion.
|
Five minutes after completion of the two-hour cycling protocol
|
|
Psycho-motor Vigilance test
Time Frame: Five minutes after completion of the 5-kilometer cycling test
|
Psycho-motor Vigilance test measured by reaction time in milliseconds
|
Five minutes after completion of the 5-kilometer cycling test
|
Secondary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
|
Plasma Osmolality
Time Frame: Plasma osmolality at 0, 30, 60, 90, and 120 minutes of the 2-hour steady cycling, at the end of the 5-kilometer cycling time trial, and within 2 minutes after the cognitive test.
|
Plasma osmolality
|
Plasma osmolality at 0, 30, 60, 90, and 120 minutes of the 2-hour steady cycling, at the end of the 5-kilometer cycling time trial, and within 2 minutes after the cognitive test.
|
|
Carbohydrate oxidation rate during exercise
Time Frame: At minutes 15, 60, and 120 of the 2-h steady-state cycling exercise
|
Carbohydrate oxidation rate during 2-h steady-state cycling exercise
|
At minutes 15, 60, and 120 of the 2-h steady-state cycling exercise
|
Collaborators and Investigators
Sponsor
Study record dates
Study Major Dates
Study Start (Estimated)
Primary Completion (Estimated)
Study Completion (Estimated)
Study Registration Dates
First Submitted
First Submitted That Met QC Criteria
First Posted (Actual)
Study Record Updates
Last Update Posted (Actual)
Last Update Submitted That Met QC Criteria
Last Verified
More Information
Terms related to this study
Additional Relevant MeSH Terms
Other Study ID Numbers
- AWD00041609
Plan for Individual participant data (IPD)
Plan to Share Individual Participant Data (IPD)?
Drug and device information, study documents
Studies a U.S. FDA-regulated drug product
Studies a U.S. FDA-regulated device product
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