ExerciseMAPLE-DRNCT07389837
Maple Syrup Carbohydrate Dose-Response on 20-km Cycling Time-Trial Performance
A study testing Maple Syrup Beverages, Pre-Trial Meals and D₂O Fluid Absorption in people with Exercise and Endurance Cycling Performance, run by Université de Montréal at 1 site in Canada.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 to 45 years, men onlyHealthy volunteers can take part
- Conditions the study is for
- Exercise, Endurance Cycling Performance, Carbohydrate Intolerance
- What is being tested?
- Maple Syrup Beverages, Pre-Trial Meals and D₂O Fluid Absorption
- Type of treatment
- Pill or oral medicine, Surgery or procedure, Lifestyle or therapy programme
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 32 participants
- Where
- 1 siteCanada
- Study dates
- 1 Feb 2026to 1 Jun 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 45 years
- Men only
- Healthy volunteers accepted
- Adult
Who may be able to join
- Age: 18-45 years.
- Relative VO2max: >55 mL·min-¹·kg-¹ for level 3; >65 mL·min-¹·kg-¹ for level 4.
- Peak Power Output (PPO): >4.6 W·kg-¹ (absolute PPO >320 W).
- Training History: >5 hours/week of cycling-specific training; >1 year of consistent endurance training.
- No history of metabolic disorders, gastrointestinal issues, or contraindications to exercise testing.
Who cannot join
- Current or past metabolic disorders (diabetes, metabolic syndrome)
- Cardiovascular disease or abnormal ECG at rest
- Gastrointestinal disorders (IBS, Crohn's, celiac disease)
- Food allergies or intolerances (particularly maple, fructose)
- Current use of medications affecting metabolism
- Smoking or nicotine use
Show all 10Show fewer
- Alcohol consumption >14 units/week
- Recent illness or injury (<4 weeks)
- Participation in other clinical trials (<3 months)
- Unable to maintain consistent training during study period
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Canada1 site
Centre EPIC
Montreal, Quebec, H1T 1N6
Simon-Olivier Cloutier, MSc, +1-514-374-1480 ext. 4259, simon-olivier.cloutier@icm-mhi.org
Louis Behrer, PhD, +1-514-827-3758, louis.bherer@icm-mhi.org
About this study
Official title: Dose-Response Effects of Maple Syrup Carbohydrate Ingestion (60, 90, 120 g/h) on 20-km Cycling Time-Trial Performance, Substrate Oxidation, and Perceptual Responses in Trained Male Cyclists
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:
Read more
- Does consuming more carbohydrate from maple syrup help participants finish a 20-kilometer cycling time trial faster?
- How do different amounts of maple syrup change how the body uses carbohydrates and fats during long exercise?
- Are higher amounts of maple syrup easy for participants to tolerate without stomach problems?
Researchers will compare four drinks:
- A placebo drink (a look-alike drink with no calories),
- A drink that provides 60 grams of carbohydrate per hour,
- A drink that provides 90 grams per hour, and
- A drink that provides 120 grams per hour.
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:
- Attend a screening visit that includes a health check and a glucose tolerance test.
- Complete a fitness test to measure their aerobic capacity and practice the cycling tests used in the study.
- Take part in four separate exercise sessions in random order. Each session includes:
- Drinking one of the four study beverages during 2 hours of steady cycling,
- Completing two short, all-out 6-second sprints during the ride,
- Completing a 20-kilometer cycling time trial as fast as possible,
- Reporting stomach symptoms and perceptions of effort,
- Providing breath, blood, urine, and sweat samples so researchers can measure how their body uses fuel.
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.
- Being tested
- Maple Syrup Beverages, placebo beverage, Pre-Trial Meals, D₂O Fluid Absorption, Time Trial Performance
- Keywords
- 13C-glucose, cycling exercise, endurance performance, carbohydrate, substrate oxidation
- Medical subject headings
- Motor Activity, Glucose-Galactose Malabsorption
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Maple Syrup BeveragesDietary supplement
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.
placebo beverageDietary supplement
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).
Pre-Trial MealsOther
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.
D₂O Fluid AbsorptionProcedure or surgery
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.
Time Trial PerformanceBehavioural
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.
Substrate OxidationProcedure or surgery
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 MetabolitesProcedure or surgery
Blood samples collected every 30 minutes measure glucose, insulin, lactate, and fatty acids. Samples are stored for later analysis of hormonal and metabolic responses.
Gastrointestinal SymptomsDiagnostic test
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.
Perceptual ResponsesDiagnostic test
Effort and muscle pain are assessed using the Borg CR100 scale during exercise and throughout the time trial at preset intervals.
Neuromuscular FatigueDiagnostic test
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.
Hedonic RatingsOther
Immediately post-exercise, a 0-100 mm scale evaluates sweetness, flavor intensity, and overall liking to assess palatability of each drink.
Blinding IntegrityOther
Bang's Blinding Index is calculated from participant guesses of drink identity to confirm whether blinding was successful.
| Study group | Role | What they receive |
|---|---|---|
| Maple syrup providing 60g of CHO per hour | Experimental | 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. Receives: 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 |
| Maple syrup providing 90g of CHO per hour | Experimental | 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. Receives: 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 |
| Maple syrup providing 120g of CHO per hour | Experimental | 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. Receives: 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 |
| Placebo | Placebo comparator | 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. Receives: 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 |
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
Measured: Immediately after completion of the 20-km time trial during each experimental visit
Secondary outcomes (6)
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.
Measured: 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.
Measured: 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.
Measured: 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.
Measured: 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.
Measured: 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.
Measured: Approximately 25-30 minutes (continuously recorded during the 20-km time trial)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Feb 2026
- Study start1 Feb 2026 (estimated)
- Primary completion30 Dec 2026 (estimated)
- Study completion1 Jun 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (8)Papers the sponsor has linked to this study.
- Other trials for ExerciseStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- This is a randomized, double-blind, placebo-controlled, crossover trial designed to maximize statistical power. Each participant will serve as their own control, completing four experimental conditions in computer-randomized order.
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 32 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Université de Montréal
- Sponsor type
- University, hospital or other
- Collaborators
- Natural Sciences and Engineering Research Council, Canada, Montreal Heart Institute, Mitacs, Quebec Maple Syrup Producers, Quebec Cycling Federation
- Responsible party
- Principal investigator, Jonathan Tremblay, Université de Montréal
- Investigators
- Jonathan Tremblay, PhD, Principal investigator, Université de Montréal
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07389837
- Sponsor's protocol ID
- ICM 2026-3568
- Acronym
- MAPLE-DR
- Status last verified
- Jan 2026
- First submitted
- 2 Jan 2026
- Last updated
- 5 Feb 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- 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.
Publications
Cermak NM, van Loon LJ. The use of carbohydrates during exercise as an ergogenic aid. Sports Med. 2013 Nov;43(11):1139-55. doi: 10.1007/s40279-013-0079-0.
PubMed 23846824Stellingwerff T, Cox GR. Systematic review: Carbohydrate supplementation on exercise performance or capacity of varying durations. Appl Physiol Nutr Metab. 2014 Sep;39(9):998-1011. doi: 10.1139/apnm-2014-0027. Epub 2014 Mar 25.
PubMed 24951297Jeukendrup AE. Carbohydrate and exercise performance: the role of multiple transportable carbohydrates. Curr Opin Clin Nutr Metab Care. 2010 Jul;13(4):452-7. doi: 10.1097/MCO.0b013e328339de9f.
PubMed 20574242Vandenbogaerde TJ, Hopkins WG. Effects of acute carbohydrate supplementation on endurance performance: a meta-analysis. Sports Med. 2011 Sep 1;41(9):773-92. doi: 10.2165/11590520-000000000-00000.
PubMed 21846165Smith JW, Zachwieja JJ, Peronnet F, Passe DH, Massicotte D, Lavoie C, Pascoe DD. Fuel selection and cycling endurance performance with ingestion of [13C]glucose: evidence for a carbohydrate dose response. J Appl Physiol (1985). 2010 Jun;108(6):1520-9. doi: 10.1152/japplphysiol.91394.2008. Epub 2010 Mar 18.
PubMed 20299609Hearris MA, Pugh JN, Langan-Evans C, Mann SJ, Burke L, Stellingwerff T, Gonzalez JT, Morton JP. 13C-glucose-fructose labeling reveals comparable exogenous CHO oxidation during exercise when consuming 120 g/h in fluid, gel, jelly chew, or coingestion. J Appl Physiol (1985). 2022 Jun 1;132(6):1394-1406. doi: 10.1152/japplphysiol.00091.2022. Epub 2022 Apr 21.
PubMed 35446596Lavoie L, Tremblay J. Ingestion of maple-based and other carbohydrate sports drinks: effect on sensory perceptions during prolonged exercise. J Int Soc Sports Nutr. 2020 Dec 9;17(1):63. doi: 10.1186/s12970-020-00384-3.
PubMed 33298104De Pauw K, Roelands B, Cheung SS, de Geus B, Rietjens G, Meeusen R. Guidelines to classify subject groups in sport-science research. Int J Sports Physiol Perform. 2013 Mar;8(2):111-22. doi: 10.1123/ijspp.8.2.111.
PubMed 23428482
Study at a glance
From the registry record, last updated by the sponsor on 5 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Dose-Response Effects of Maple Syrup Carbohydrate Ingestion (60, 90, 120 g/h) on 20-km Cycling Time-Trial Performance, Substrate Oxidation, and Perceptual Responses in Trained Male Cyclists
- ClinicalTrials.gov ID
- NCT07389837
- Acronym / sponsor ID
- MAPLE-DR / ICM 2026-3568
- Keywords
- 13C-glucose, cycling exercise, endurance performance, carbohydrate, substrate oxidation
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 32 participants (estimated)
- Lead sponsor
- Université de MontréalUniversity, hospital or other
- Collaborators
- Natural Sciences and Engineering Research Council, Canada, Montreal Heart Institute, Mitacs, Quebec Maple Syrup Producers, Quebec Cycling Federation
- Study start
- 1 Feb 2026 (estimated)
- Primary completion
- 30 Dec 2026 (estimated)
- Study completion
- 1 Jun 2027 (estimated)
- First posted
- 5 Feb 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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:
- Does consuming more carbohydrate from maple syrup help participants finish a 20-kilometer cycling time trial faster?
- How do different amounts of maple syrup change how the body uses carbohydrates and fats during long exercise?
- Are higher amounts of maple syrup easy for participants to tolerate without stomach problems?
Researchers will compare four drinks:
- A placebo drink (a look-alike drink with no calories),
- A drink that provides 60 grams of carbohydrate per hour,
- A drink that provides 90 grams per hour, and
- A drink that provides 120 grams per hour.
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:
- Attend a screening visit that includes a health check and a glucose tolerance test.
- Complete a fitness test to measure their aerobic capacity and practice the cycling tests used in the study.
- Take part in four separate exercise sessions in random order. Each session includes:
- Drinking one of the four study beverages during 2 hours of steady cycling,
- Completing two short, all-out 6-second sprints during the ride,
- Completing a 20-kilometer cycling time trial as fast as possible,
- Reporting stomach symptoms and perceptions of effort,
- Providing breath, blood, urine, and sweat samples so researchers can measure how their body uses fuel.
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.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind (participant, investigator)
- Number of arms
- 4
- Model description
- This is a randomized, double-blind, placebo-controlled, crossover trial designed to maximize statistical power. Each participant will serve as their own control, completing four experimental conditions in computer-randomized order.
| Arm | Type | Receives |
|---|---|---|
| Maple syrup providing 60g of CHO per hour | Experimental | 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 IntegrityThe 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. |
| Maple syrup providing 90g of CHO per hour | Experimental | 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 IntegrityThe 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. |
| Maple syrup providing 120g of CHO per hour | Experimental | 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 IntegrityThe 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. |
| Placebo | Placebo comparator | 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 IntegrityThe 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. |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- Male only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- Age: 18-45 years.
- Relative VO2max: >55 mL·min-¹·kg-¹ for level 3; >65 mL·min-¹·kg-¹ for level 4.
- Peak Power Output (PPO): >4.6 W·kg-¹ (absolute PPO >320 W).
- Training History: >5 hours/week of cycling-specific training; >1 year of consistent endurance training.
- No history of metabolic disorders, gastrointestinal issues, or contraindications to exercise testing.
Key exclusion criteria (10 listed)
- Current or past metabolic disorders (diabetes, metabolic syndrome)
- Cardiovascular disease or abnormal ECG at rest
- Gastrointestinal disorders (IBS, Crohn's, celiac disease)
- Food allergies or intolerances (particularly maple, fructose)
- Current use of medications affecting metabolism
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Maple Syrup BeveragesPure 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. | Dietary supplement | Maple syrup providing 120g of CHO per hour, Maple syrup providing 60g of CHO per hour, Maple syrup providing 90g of CHO per hour, Placebo |
| placebo beverageParticipants 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). | Dietary supplement | Maple syrup providing 120g of CHO per hour, Maple syrup providing 60g of CHO per hour, Maple syrup providing 90g of CHO per hour, Placebo |
| Pre-Trial MealsTo 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. | Other | Maple syrup providing 120g of CHO per hour, Maple syrup providing 60g of CHO per hour, Maple syrup providing 90g of CHO per hour, Placebo |
| D₂O Fluid AbsorptionAt 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. | Procedure or surgery | Maple syrup providing 120g of CHO per hour, Maple syrup providing 60g of CHO per hour, Maple syrup providing 90g of CHO per hour, Placebo |
| Time Trial PerformanceAfter 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. | Behavioural | Maple syrup providing 120g of CHO per hour, Maple syrup providing 60g of CHO per hour, Maple syrup providing 90g of CHO per hour, Placebo |
| Substrate OxidationEnergy 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. | Procedure or surgery | Maple syrup providing 120g of CHO per hour, Maple syrup providing 60g of CHO per hour, Maple syrup providing 90g of CHO per hour, Placebo |
| Blood MetabolitesBlood samples collected every 30 minutes measure glucose, insulin, lactate, and fatty acids. Samples are stored for later analysis of hormonal and metabolic responses. | Procedure or surgery | Maple syrup providing 120g of CHO per hour, Maple syrup providing 60g of CHO per hour, Maple syrup providing 90g of CHO per hour, Placebo |
| Gastrointestinal SymptomsParticipants 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. | Diagnostic test | Maple syrup providing 120g of CHO per hour, Maple syrup providing 60g of CHO per hour, Maple syrup providing 90g of CHO per hour, Placebo |
| Perceptual ResponsesEffort and muscle pain are assessed using the Borg CR100 scale during exercise and throughout the time trial at preset intervals. | Diagnostic test | Maple syrup providing 120g of CHO per hour, Maple syrup providing 60g of CHO per hour, Maple syrup providing 90g of CHO per hour, Placebo |
| Neuromuscular FatigueParticipants 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. | Diagnostic test | Maple syrup providing 120g of CHO per hour, Maple syrup providing 60g of CHO per hour, Maple syrup providing 90g of CHO per hour, Placebo |
| Hedonic RatingsImmediately post-exercise, a 0-100 mm scale evaluates sweetness, flavor intensity, and overall liking to assess palatability of each drink. | Other | Maple syrup providing 120g of CHO per hour, Maple syrup providing 60g of CHO per hour, Maple syrup providing 90g of CHO per hour, Placebo |
| Blinding IntegrityBang's Blinding Index is calculated from participant guesses of drink identity to confirm whether blinding was successful. | Other | Maple syrup providing 120g of CHO per hour, Maple syrup providing 60g of CHO per hour, Maple syrup providing 90g of CHO per hour, Placebo |
Primary outcome
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.
Time frame: Immediately after completion of the 20-km time trial during each experimental visit
20-km time trial completion time (minutes), measured at the end of each experimental visit.
6 secondary outcomes
Substrate oxidation rates during exercise
Time frame: At rest, immediately before exercise, and every 30 minutes during 120 minutes of constant-load cycling
Plasma metabolite concentrations
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
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.
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
Time frame: Baseline, 60 minutes, 120 minutes, and immediately after time trial
Mean power output during 20-km time trial
Time frame: Approximately 25-30 minutes (continuously recorded during the 20-km time trial)
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 Feb 2026.
- Background: PubMed 23846824Cermak NM, van Loon LJ. The use of carbohydrates during exercise as an ergogenic aid. Sports Med. 2013 Nov;43(11):1139-55. doi: 10.1007/s40279-013-0079-0.
- Background: PubMed 24951297Stellingwerff T, Cox GR. Systematic review: Carbohydrate supplementation on exercise performance or capacity of varying durations. Appl Physiol Nutr Metab. 2014 Sep;39(9):998-1011. doi: 10.1139/apnm-2014-0027. Epub 2014 Mar 25.
- Background: PubMed 20574242Jeukendrup AE. Carbohydrate and exercise performance: the role of multiple transportable carbohydrates. Curr Opin Clin Nutr Metab Care. 2010 Jul;13(4):452-7. doi: 10.1097/MCO.0b013e328339de9f.
- Background: PubMed 21846165Vandenbogaerde TJ, Hopkins WG. Effects of acute carbohydrate supplementation on endurance performance: a meta-analysis. Sports Med. 2011 Sep 1;41(9):773-92. doi: 10.2165/11590520-000000000-00000.
- Background: PubMed 20299609Smith JW, Zachwieja JJ, Peronnet F, Passe DH, Massicotte D, Lavoie C, Pascoe DD. Fuel selection and cycling endurance performance with ingestion of [13C]glucose: evidence for a carbohydrate dose response. J Appl Physiol (1985). 2010 Jun;108(6):1520-9. doi: 10.1152/japplphysiol.91394.2008. Epub 2010 Mar 18.
- Background: PubMed 35446596Hearris MA, Pugh JN, Langan-Evans C, Mann SJ, Burke L, Stellingwerff T, Gonzalez JT, Morton JP. 13C-glucose-fructose labeling reveals comparable exogenous CHO oxidation during exercise when consuming 120 g/h in fluid, gel, jelly chew, or coingestion. J Appl Physiol (1985). 2022 Jun 1;132(6):1394-1406. doi: 10.1152/japplphysiol.00091.2022. Epub 2022 Apr 21.
- Background: PubMed 33298104Lavoie L, Tremblay J. Ingestion of maple-based and other carbohydrate sports drinks: effect on sensory perceptions during prolonged exercise. J Int Soc Sports Nutr. 2020 Dec 9;17(1):63. doi: 10.1186/s12970-020-00384-3.
- Background: PubMed 23428482De Pauw K, Roelands B, Cheung SS, de Geus B, Rietjens G, Meeusen R. Guidelines to classify subject groups in sport-science research. Int J Sports Physiol Perform. 2013 Mar;8(2):111-22. doi: 10.1123/ijspp.8.2.111.
- Individual participant dataSharing planned: 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.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Jonathan Tremblay, PhD principal investigator
Université de Montréal
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Maple Syrup Beverages, Pre-Trial Meals and D₂O Fluid Absorption in people with Exercise and Endurance Cycling Performance, run by Université de Montréal at 1 site in Canada.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 5 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Canada. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Philippe Parent, BSc (+1-438-393-9720, philippe.parent.1@umontreal.ca), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
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. (time frame: Immediately after completion of the 20-km time trial during each experimental visit). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07389837, which also lists 8 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 5 Feb 2026; AzTrials last refreshed its copy on 26 Oct 2026.