An interventional study of Maple Syrup Beverages and placebo beverage in Exercise, Endurance Cycling Performance and Carbohydrate Intolerance, sponsored by Université de Montréal. Not yet recruiting at 1 site in Canada. Open to male participants aged 18 Years to 45 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-02-05.
Sponsored by Université de Montréal · Not applicable, Interventional, and Basic science
The goal of this clinical trial is to learn whether maple syrup can be used as a natural carbohydrate source to help trained male cyclists perform better during long-duration cycling. The study also aims to learn how different amounts of maple syrup affect energy use in the body, stomach comfort, and feelings of effort and fatigue.
The main questions the study aims to answer are:
Researchers will compare four drinks:
They will compare these drinks to see whether higher carbohydrate amounts lead to better cycling performance and how each dose affects comfort and metabolism.
Participants will:
All drinks will look, taste, and smell similar so participants cannot tell which one they are receiving. Meals before each session will be provided to keep conditions the same across visits.
This study may help athletes and active people choose natural carbohydrate sources that support both performance and comfort during long endurance exercise. The findings may also guide future research on the use of maple syrup as a sports nutrition option.
9,798 studies on the registry are indexed under Motor Activity; 1,910 are open to participants now.
This study's planned enrollment of 32 is below the median of 60 across 8,388 interventional studies indexed under Motor Activity.
Browse Motor Activity studies →Université de Montréal is the lead sponsor of 98 studies on the registry; 11 are open to participants now.
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Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ECG (electrocardiogram)
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The protocol begins with a 10-minute warm-up at 100 W, followed by a 120-minute constant-load cycling phase at 65% PPO, during which the 60 g/h maple syrup solution is consumed every 15 minutes as the main intervention. Neuromuscular fatigue is assessed four times (baseline, 60 min, 120 min into the constant-load, and post-TT) using two 6-second all-out seated sprints (from a 100 W rolling start); these two sprints are separated by a 1-minute active recovery at 100 W, after which the 65% PPO cycling is immediately resumed for the in-exercise timepoints. The constant-load phase is concluded by a 5-minute complete recovery, immediately followed by the 20-km self-paced Time Trial (completed without fluids), with the final set of sprints performed immediately after the TT to assess residual fatigue.
Dietary Supplement: Maple Syrup Beverages · Dietary Supplement: placebo beverage · Other: Pre-Trial Meals · Procedure: D₂O Fluid Absorption · Behavioral: Time Trial Performance · Procedure: Substrate Oxidation · Procedure: Blood Metabolites · Diagnostic Test: Gastrointestinal Symptoms · Diagnostic Test: Perceptual Responses · Diagnostic Test: Neuromuscular Fatigue · Other: Hedonic Ratings · Other: Blinding Integrity
The protocol begins with a 10-minute warm-up at 100 W, followed by a 120-minute constant-load cycling phase at 65% PPO, during which the 90 g/h maple syrup solution is consumed every 15 minutes as the main intervention. Neuromuscular fatigue is assessed four times (baseline, 60 min, 120 min into the constant-load, and post-TT) using two 6-second all-out seated sprints (from a 100 W rolling start); these two sprints are separated by a 1-minute active recovery at 100 W, after which the 65% PPO cycling is immediately resumed for the in-exercise timepoints. The constant-load phase is concluded by a 5-minute complete recovery, immediately followed by the 20-km self-paced Time Trial (completed without fluids), with the final set of sprints performed immediately after the TT to assess residual fatigue.
Dietary Supplement: Maple Syrup Beverages · Dietary Supplement: placebo beverage · Other: Pre-Trial Meals · Procedure: D₂O Fluid Absorption · Behavioral: Time Trial Performance · Procedure: Substrate Oxidation · Procedure: Blood Metabolites · Diagnostic Test: Gastrointestinal Symptoms · Diagnostic Test: Perceptual Responses · Diagnostic Test: Neuromuscular Fatigue · Other: Hedonic Ratings · Other: Blinding Integrity
The protocol begins with a 10-minute warm-up at 100 W, followed by a 120-minute constant-load cycling phase at 65% PPO, during which the 120 g/h maple syrup solution is consumed every 15 minutes as the main intervention. Neuromuscular fatigue is assessed four times (baseline, 60 min, 120 min into the constant-load, and post-TT) using two 6-second all-out seated sprints (from a 100 W rolling start); these two sprints are separated by a 1-minute active recovery at 100 W, after which the 65% PPO cycling is immediately resumed for the in-exercise timepoints. The constant-load phase is concluded by a 5-minute complete recovery, immediately followed by the 20-km self-paced Time Trial (completed without fluids), with the final set of sprints performed immediately after the TT to assess residual fatigue.
Dietary Supplement: Maple Syrup Beverages · Dietary Supplement: placebo beverage · Other: Pre-Trial Meals · Procedure: D₂O Fluid Absorption · Behavioral: Time Trial Performance · Procedure: Substrate Oxidation · Procedure: Blood Metabolites · Diagnostic Test: Gastrointestinal Symptoms · Diagnostic Test: Perceptual Responses · Diagnostic Test: Neuromuscular Fatigue · Other: Hedonic Ratings · Other: Blinding Integrity
The protocol begins with a 10-minute warm-up at 100 W, followed by a 120-minute constant-load cycling phase at 65% PPO, during which the placebo solution (sweetened water, with sotolon for maple taste) is consumed every 15 minutes as the main intervention. Neuromuscular fatigue is assessed four times (baseline, 60 min, 120 min into the constant-load, and post-TT) using two 6-second all-out seated sprints (from a 100 W rolling start); these two sprints are separated by a 1-minute active recovery at 100 W, after which the 65% PPO cycling is immediately resumed for the in-exercise timepoints. The constant-load phase is concluded by a 5-minute complete recovery, immediately followed by the 20-km self-paced Time Trial (completed without fluids), with the final set of sprints performed immediately after the TT to assess residual fatigue.
Dietary Supplement: Maple Syrup Beverages · Dietary Supplement: placebo beverage · Other: Pre-Trial Meals · Procedure: D₂O Fluid Absorption · Behavioral: Time Trial Performance · Procedure: Substrate Oxidation · Procedure: Blood Metabolites · Diagnostic Test: Gastrointestinal Symptoms · Diagnostic Test: Perceptual Responses · Diagnostic Test: Neuromuscular Fatigue · Other: Hedonic Ratings · Other: Blinding Integrity
Pure maple syrup is diluted in water and mixed with electrolytes (sodium, potassium, magnesium) to resemble a sports drink. Participants receive one of three carbohydrate doses (60, 90, or 120 g per hour). Drinks are ingested every 15 minutes during 120 minutes of cycling, for a total of \~750 mL per hour. All doses have the same volume, temperature, electrolyte content, and schedule.
Participants receive a calorie-free electrolyte drink designed to mimic maple syrup. Sotolon (maple aroma) and stevia are added in small amounts to reproduce sweetness, flavor, and smell without providing energy. The drink is administered in identical volumes and timing to the maple syrup beverages (\~750 mL per hour, every 15 minutes).
To control nutrition before each trial, participants are provided with a standardized dinner the night before and a standardized breakfast 2-3 hours before testing. Meals contain the same calories and macronutrient distribution across all sessions. Participants must also replicate their training during the previous 48 hours.
At 30 minutes of cycling, participants ingest a small, safe dose of deuterium oxide (7-8 mL) to measure fluid absorption and gastric emptying. Additional blood samples are collected at +32, +35, and +40 minutes to capture early absorption. Urine is collected to measure deuterium enrichment and validate absorption kinetics.
After 120 minutes of steady cycling, participants complete a 20-km self-paced time trial. Only distance is displayed. The primary outcome is completion time; mean power is analyzed as supportive information.
Energy metabolism is measured using indirect calorimetry and ¹³C-sucrose breath enrichment. Samples are collected at rest and every 30 minutes during exercise to quantify carbohydrate and fat use, distinguishing ingested vs. stored carbohydrate oxidation. Urine and sweat correct protein oxidation.
Blood samples collected every 30 minutes measure glucose, insulin, lactate, and fatty acids. Samples are stored for later analysis of hormonal and metabolic responses.
Participants rate stomach symptoms (0-10 scale) before exercise, every 30 minutes during cycling, and after the time trial. Scores quantify total, upper, and lower GI discomfort.
Effort and muscle pain are assessed using the Borg CR100 scale during exercise and throughout the time trial at preset intervals.
Participants perform two 6-second maximal sprints at baseline, 60 and 120 minutes of cycling, and after the time trial. Peak power, cadence, and torque assess fatigue progression and recovery.
Immediately post-exercise, a 0-100 mm scale evaluates sweetness, flavor intensity, and overall liking to assess palatability of each drink.
Bang's Blinding Index is calculated from participant guesses of drink identity to confirm whether blinding was successful.
Assess the dose-response effect of maple syrup carbohydrate ingestion (0, 60, 90, 120 g·h-¹) on 20-km cycling time-trial performance in trained male cyclists.
20-km time trial completion time (minutes), measured at the end of each experimental visit.
Time frame: Immediately after completion of the 20-km time trial during each experimental visit
Substrate oxidation rates during exercise
Exogenous and endogenous carbohydrate oxidation, fat oxidation, and protein oxidation rates (g·min-¹) measured via ¹³C stable isotope breath enrichment and indirect calorimetry.
Time frame: At rest, immediately before exercise, and every 30 minutes during 120 minutes of constant-load cycling
Plasma metabolite concentrations
Plasma glucose, insulin, lactate, and free fatty acid concentrations sampled before beverage ingestion, pre-exercise, every 30 minutes during constant-load exercise, and immediately after.
Time frame: Measured before beverage ingestion, immediately pre-exercise, every 30 minutes during the 120-minute constant-load cycling, and immediately post-exercise (before the time trial).
Ratings of perceived effort during exercise
Ratings of perceived effort (CR100 scale, 0-100) collected after 3 minutes and every 30 minutes during constant-load exercise, and during the time trial.
Time frame: Assessed 3 minutes after exercise begins; every 30 minutes during the constant-load cycling (30, 60, 90, 120 min); and at approximately 126, 127, 130, 136, and 145 minutes (corresponding to 0.5, 5, 10, 15, and 20 km during the time trial)
Assess gastrointestinal tolerance and symptoms across maple syrup doses and placebo.
Gastrointestinal distress scores (0-10 on a modified visual analog scale, mVAS), rated pre-exercise, every 30 minutes during the constant-load exercise, and post-TT; includes composite scores for total, upper, and lower GI symptoms.
Time frame: Measured pre-exercise; every 30 minutes during the 120-minute constant-load cycling (30, 60, 90, 120 min); and immediately after the time trial.
Peak power output during maximal sprints
Peak power output (watts) from two 6-second maximal sprints performed at baseline, 60 minutes, 120 minutes, and post-time trial.
Time frame: Baseline, 60 minutes, 120 minutes, and immediately after time trial
Mean power output during 20-km time trial
Mean power output (watts) recorded continuously during the 20-km time trial.
Time frame: Approximately 25-30 minutes (continuously recorded during the 20-km time trial)
Hedonic ratings for beverage sweetness, flavor, and liking
Hedonic ratings for sweetness, flavor intensity, and overall liking (0-100 mm visual analog scale) assessed immediately post-exercise.
Time frame: Immediately after time trial completion
Explore correlations between substrate oxidation rates and TT performance.
Correlation coefficients (e.g., Pearson's r) between exogenous/endogenous oxidation rates and TT time to completion or mean power output.
Time frame: Evaluated using oxidation values measured during cycling (at rest, pre-exercise, and at 30, 60, 90, 120 min) and TT performance measured at approximately 150-155 minutes (immediately after time trial completion)
Examine inter-individual variability in dose-response patterns for performance outcomes.
Within-subject and inter-individual coefficients of variation for TT time to completion and mean power output across doses.
Time frame: Calculated from repeated TT measurements collected at each of 4 experimental visits over approximately 4-6 weeks
Assess gastrointestinal absorption kinetics across maple syrup doses and placebo.
Deuterium oxide (D2O) tracer kinetics, including absorption rate constant, time-to-peak plasma enrichment (tmax), and area under the curve (AUC), derived from plasma and urine D/H enrichment samples.
Time frame: Measured via plasma samples at baseline, 30 min (pre-ingestion), and at +32, +35, +40 min, then every 30 min during cycling (60, 90, 120 min), plus within 30 minutes after time trial completion (approximately 150-180 min)
Explore whether individual characteristics (e.g., body weight, training volume) moderate the dose-response effects of maple syrup on endurance performance.
Moderation analysis using interaction terms in linear mixed-effects models (e.g., carbohydrate dose × body weight) for TT time to completion.
Time frame: Moderation assessed using TT outcomes collected at each of 4 experimental visits over approximately 4-8 weeks, combined with participant baseline characteristics collected at screening visit
Explore plasma metabolomic signatures associated with carbohydrate dose and performance.
Untargeted metabolomic profiling via high-resolution liquid chromatography-tandem mass spectrometry (LC-MS/MS) on plasma samples collected at before beverage ingestion, before the start of exercise, at 60 minutes into constant-load exercise, pre- and post-TT; focuses on pathways such as glycolysis, lipid oxidation, and amino acid metabolism.
Time frame: Baseline (before beverage ingestion), immediately before exercise, at 60 minutes of constant-load cycling, pre-TT (~125 minutes after beginning constand-load cycling), and post-TT (~150-160 minutes).
Plan to share: Yes — De-identified, row-level participant data collected in this trial, including: 20-km TT completion time and mean power; VO2max and PPO from incremental test; whole-body substrate oxidation (carbohydrate, fat, protein) and exogenous/endogenous carbohydrate oxidation from 13C breath enrichment; respiratory gas exchange (VO2, VCO2); plasma biomarkers (glucose, insulin, lactate, free fatty acids) at scheduled time points; D2O fluid absorption kinetics (rate constant, tmax, AUC); gastrointestinal symptom scores (mVAS); perceptual responses (Borg CR100 effort and muscle pain); neuromuscular fatigue metrics (6-s sprints: peak power, cadence, torque) at all timepoints; hedonic ratings (sweetness, flavor, overall liking); blinding guesses (Bang's index); and baseline demographics (age, body mass). Direct identifiers will be removed; dates and rare combinations will be masked per de-identification standards.
Supporting information: Study protocol, Statistical analysis plan, Analytic code
Time frame: 12 months after primary results publication and for at least 5 years
Access criteria: Qualified researchers at accredited institutions may request access to de-identified IPD and supporting materials (protocol, SAP, and analytic code if available). Requests must include a study synopsis, analysis plan, variables needed, and documentation of IRB/ethics approval. The PI/sponsor data access committee will review for scientific merit, feasibility, and privacy protection. Approved users must sign a Data Use Agreement prohibiting re-identification, onward sharing, and commercial use; publications must acknowledge the original study. Access will be time-limited via a secure repository with role-based permissions, encryption, and audit logs; only aggregate results may be publicly released. Linkage to external datasets requires explicit approval.
Data sharing details ↗ · bioenergeticslab.ca
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Université de Montréal