Maple Products and Exercise Performance
Not Applicable
Completed
- Conditions
- Carbohydrate IngestionFuel SelectionAthletic Performance
- Interventions
- Dietary Supplement: Solution ingestionBehavioral: Constant load cyclingProcedure: Expired gas samplingProcedure: Indirect respiratory calorimetryOther: PalatabilityOther: GastrointestinalProcedure: Blood samplingBehavioral: Time trial
- Registration Number
- NCT02880124
- Lead Sponsor
- Université de Montréal
- Brief Summary
The purpose of this study is to compare the acute metabolic responses and time-trial performance following the ingestion of carbohydrate solutions containing either maple syrup, maple sap, corn syrup, a commercial sport drink or water.
- Detailed Description
The study will require 4 meetings for each subject: a 30-minute meeting to explain the project; a meeting of 2 hours (glucose tolerance test, at rest); a one-hour meeting (maximum oxygen consumption test (VO2max) during an exercise conducted on an electromagnetically braked cycle ergometer, and a meeting of about 4 hours for experimentation (120-min exercise on a stationary bicycle with ingestion of a solution carbohydrates or sweetened water, and a 20-km time trial).
Visit #1 - Pre-participation (screening visit) Following an initial contact by phone or email, the subject will be invited to individual meetings which will last about 15 minutes. During the meeting, one of the project managers will check the eligibility of the potential subject in the study and, if eligible, will present him the details of the protocol specifying the discomforts and risks involved. The participant will be required to fill a Physical Activity Readiness Questionnaire (PAR-Q) and will be given a copy of the consent form. We will request the name and contact details of a person to contact in case of emergency, this information will be recorded and preserved in the subject matter. A period of at least three days will be allocated to make the decision whether to participate in the study or not. If the participant decides to participate in the study, he will be invited for the second visit (oral glucose tolerance test) and on this occasion will sign the consent form.
Visit #2 - Oral glucose tolerance test (OGTT) This test will be performed at Exercise Physiology Laboratory at the Department of kinesiology from the University of Montreal under the procedure commonly used for these tests. This procedure requires the ingestion of 300 mL of water containing 75 g of glucose in the morning (around 8am) after 12 hours of fasting, and blood samples and on the tip of a finger at 0, 60 and 120 minutes for the measurement of blood glucose. Subjects with higher blood glucose than 5 mmol/L before ingestion of glucose and greater than 8 mmol/L after ingestion (60 or 120 min) will not be considered for the study. These glucose tolerance standards are more stringent than those of the World Health Organization, because the objective of this test is not a diagnosis on glucose tolerance or a prognosis of its future development, but just n include in the study subjects who have good glucose tolerance.
Visit #3 - Maximum oxygen uptake testing: cycling VO2max This test will be conducted in the Exercise Physiology Laboratory at the Department of kinesiology from the University of Montreal. Exercise involves pedaling a stationary bike at a power output (resistance) gradually increasing until reaching VO2max. During the execution of the test, the subject is wearing surface electrodes to measure heart rate, a mouthpiece and nose clip to measure the volume of expired gas as well as the oxygen and carbon dioxide content to determine the consumption oxygen and carbon dioxide production. This type of testing is routinely used in our laboratory. The test can be stopped at any time by the will of the subject. For this test, guidelines established by the Exercise Physiology Laboratory at the Department of kinesiology from the University of Montreal will be followed. These guidelines are based on recommendations of ethics and safety of the "American College of Sports Medicine".
4- Experimentation The tests will be conducted at the Exercise Physiology Laboratory at the Department of kinesiology from the University of Montreal. The exercise is carried out on stationary cycle ergometer. It lasts 120 minutes at a power output corresponding to 60% of the VO2max obtained during the maximal test. A volume of a carbohydrate solution (120 g, 6% carbohydrate by volume) or sweetened water will be administered to the subject before (571 mL) and during exercise (286 mL every 30 minutes). The following solutions will be administered in a balanced, randomized, double-blind model: maple sap, maple syrup, glucose, a commercial sports drink and water with a glucose trace (0.001% carbohydrate by volume). Under conditions where only a trace of water or glucose are administered, a natural sweetener (stevia) will be added to obtain a sweet taste similar to other conditions. Carbohydrate solutions will all be artificially enriched in 13C. The volume ingested after 30 minutes of exercise will be artificially enriched in deuterium (D2O, 8g incorporated in the ingestion of 286 mL).
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- Male
- Target Recruitment
- 76
Inclusion Criteria
- Low alcohol consumption (<3 drinks/week)
- Not regularly taking medication for a known pathology
- Regularly practices endurance sports (cycling, running, etc.)
Exclusion Criteria
- Intolerant to glucose (according to WHO standards)
- Musculoskeletal injury or illness affecting exercise performance
- Failure to respect protocol guidelines (diet, exercise prior to experimentation, etc.)
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description Maple syrup Solution ingestion A maple syrup solution of 6% carbohydrate per volume labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Maple syrup Time trial A maple syrup solution of 6% carbohydrate per volume labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Glucose Constant load cycling A glucose solution of 6% carbohydrate per volume labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Maple sap Solution ingestion A maple sap solution of 6% carbohydrate per volume labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Maple sap Expired gas sampling A maple sap solution of 6% carbohydrate per volume labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Maple syrup Expired gas sampling A maple syrup solution of 6% carbohydrate per volume labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Maple sap Blood sampling A maple sap solution of 6% carbohydrate per volume labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Maple syrup Indirect respiratory calorimetry A maple syrup solution of 6% carbohydrate per volume labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Maple syrup Palatability A maple syrup solution of 6% carbohydrate per volume labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Maple sap Constant load cycling A maple sap solution of 6% carbohydrate per volume labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Maple sap Indirect respiratory calorimetry A maple sap solution of 6% carbohydrate per volume labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Maple syrup Constant load cycling A maple syrup solution of 6% carbohydrate per volume labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Maple syrup Gastrointestinal A maple syrup solution of 6% carbohydrate per volume labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Maple syrup Blood sampling A maple syrup solution of 6% carbohydrate per volume labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Glucose Blood sampling A glucose solution of 6% carbohydrate per volume labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Maple sap Palatability A maple sap solution of 6% carbohydrate per volume labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Sport drink Constant load cycling A Gatorade (TM) solution of 6% carbohydrate per volume labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Sport drink Palatability A Gatorade (TM) solution of 6% carbohydrate per volume labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Sport drink Time trial A Gatorade (TM) solution of 6% carbohydrate per volume labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Trace Indirect respiratory calorimetry A solution containing stevia (sugar substitute) and trace amounts of glucose (3g) labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Maple sap Gastrointestinal A maple sap solution of 6% carbohydrate per volume labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Maple sap Time trial A maple sap solution of 6% carbohydrate per volume labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Glucose Solution ingestion A glucose solution of 6% carbohydrate per volume labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Glucose Time trial A glucose solution of 6% carbohydrate per volume labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Sport drink Expired gas sampling A Gatorade (TM) solution of 6% carbohydrate per volume labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Sport drink Indirect respiratory calorimetry A Gatorade (TM) solution of 6% carbohydrate per volume labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Glucose Expired gas sampling A glucose solution of 6% carbohydrate per volume labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Glucose Indirect respiratory calorimetry A glucose solution of 6% carbohydrate per volume labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Glucose Palatability A glucose solution of 6% carbohydrate per volume labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Glucose Gastrointestinal A glucose solution of 6% carbohydrate per volume labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Sport drink Solution ingestion A Gatorade (TM) solution of 6% carbohydrate per volume labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Sport drink Gastrointestinal A Gatorade (TM) solution of 6% carbohydrate per volume labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Sport drink Blood sampling A Gatorade (TM) solution of 6% carbohydrate per volume labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Trace Solution ingestion A solution containing stevia (sugar substitute) and trace amounts of glucose (3g) labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Trace Gastrointestinal A solution containing stevia (sugar substitute) and trace amounts of glucose (3g) labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Trace Constant load cycling A solution containing stevia (sugar substitute) and trace amounts of glucose (3g) labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Trace Expired gas sampling A solution containing stevia (sugar substitute) and trace amounts of glucose (3g) labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Trace Palatability A solution containing stevia (sugar substitute) and trace amounts of glucose (3g) labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Trace Time trial A solution containing stevia (sugar substitute) and trace amounts of glucose (3g) labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial. Trace Blood sampling A solution containing stevia (sugar substitute) and trace amounts of glucose (3g) labeled with 13C-sucrose will be ingested 30 min prior to starting exercise and every 30 min thereafter (solution ingestion), until 2h of the constant load cycling exercise is completed. Starting 4 min before each solution ingested over the protocol, indirect respiratory calorimetry, expired gas sampling, blood sampling will occur. After completing the 2h of exercise, subjects will be given a few minutes of rest (5-min) during which the catheter will be removed, after which the 20-km time trial will be initiated on the same ergometer. Palatability of the solution will be assessed after the first ingestion and after ingesting the last solution. Gastrointestinal symptoms will be assessed after the time trial.
- Primary Outcome Measures
Name Time Method Exercise performance in the 20-km time trial At the end of 2 hours of exercise Duration to complete distance and mean power sustained during the performance
Exogenous carbohydrate oxidation Every 30 minutes during the exercise protocol, during 3 minutes of expired gas collection. Measured by indirect respiratory calorimetry combined with tracer techniques.
- Secondary Outcome Measures
Name Time Method Oxidation of glucose released by the liver Every 30 minutes during the exercise protocol, during 3 minutes of expired gas collection. Measured by indirect respiratory calorimetry combined with tracer techniques. Average of 3 minutes of steady-state expired gas collection.
Blood insulin concentration Every 30 minutes during the exercise protocol Blood is sampled using a venous catheter over about 60 seconds. Following centrifugation to extract the plasma, a small sample is used to measure insulin concentration.
Blood lactate concentration Every 30 minutes during the exercise protocol Blood is sampled using a venous catheter over about 60 seconds. Following centrifugation to extract the plasma, a small sample is used to measure lactate concentration.
Blood glucose concentration Every 30 minutes during the exercise protocol Blood is sampled using a venous catheter over about 60 seconds. Following centrifugation to extract the plasma, a small sample is used to measure glucose concentration.
Muscle glycogen oxidation Every 30 minutes during the exercise protocol, during 3 minutes of expired gas collection. Measured by indirect respiratory calorimetry combined with tracer techniques.
Blood free fatty acid concentration Every 30 minutes during the exercise protocol Blood is sampled using a venous catheter over about 60 seconds. Following centrifugation to extract the plasma, a small sample is used to measure free fatty acid concentration.
Total carbohydrate oxidation Every 30 minutes during the exercise protocol, during 3 minutes of expired gas collection. Measured by indirect respiratory calorimetry.
Trial Locations
- Locations (1)
Centre d'éducation physique et sportive de l'Université de Montréal (CEPSUM)
🇨🇦Montréal, Quebec, Canada
Centre d'éducation physique et sportive de l'Université de Montréal (CEPSUM)🇨🇦Montréal, Quebec, Canada