An interventional study of Anhydrous Betaine and Placebo in Exercise and Hydration, sponsored by Poznan University of Life Sciences. Not yet recruiting. Open to participants aged 18 Years to 45 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-09-25.
Sponsored by Poznan University of Life Sciences · Not applicable, Interventional, and Other
This randomized, double-blind, placebo-controlled crossover study will investigate whether acute betaine ingestion as part of a pre-exercise hyperhydration strategy improves endurance running performance and influences hydration-related responses during prolonged exercise.
Approximately 30 recreationally trained male and premenopausal female runners will complete two experimental trials: a betaine condition and a placebo/control condition. In the betaine condition, participants will ingest anhydrous betaine at a dose of 0.07 g/kg body mass as part of a standardized pre-exercise hydration protocol providing a total fluid intake of approximately 25 mL/kg body mass.
Following the hydration protocol, participants will complete 60 minutes of treadmill running at 60% of the running velocity corresponding to VO₂max, followed by a 5-minute recovery period and a 5-km treadmill time trial.
The primary outcome will be 5-km running time-trial performance. Secondary outcomes will include exercise-induced fluid and sweat loss, urinary hydration markers, sweat electrolyte concentrations, physiological responses, exercise economy, substrate utilization, blood lactate concentration, perceived exertion, thirst, and thermal sensation.
9,798 studies on the registry are indexed under Motor Activity; 1,910 are open to participants now.
This study's planned enrollment of 20 is below the median of 60 across 8,388 interventional studies indexed under Motor Activity.
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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.
Periods have stopped for good: usually no period for 12 months in a row without another medical reason, sometimes confirmed by a blood test (FSH).
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
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.
Postmenopausal
Periods have stopped for good: usually no period for 12 months in a row without another medical reason, sometimes confirmed by a blood test (FSH).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Participants will first complete the betaine-enriched hyperhydration condition. After the washout period, they will complete the placebo hyperhydration condition.
Dietary Supplement: Anhydrous Betaine · Other: Placebo
Participants will first complete the placebo hyperhydration condition. After the washout period, they will complete the betaine-enriched hyperhydration condition.
Dietary Supplement: Anhydrous Betaine · Other: Placebo
Anhydrous betaine (trimethylglycine) will be administered as a single dose of 0.07 g/kg body mass, dissolved in a commercially available sports drink (5 mL/kg body mass), 150 minutes before exercise. The betaine-containing drink will constitute the first bolus of a standardized pre-exercise hyperhydration protocol providing a total fluid intake of approximately 25 mL/kg body mass over 120 minutes.
Participants will receive the same commercially available sports drink (5 mL/kg body mass) without added betaine 150 minutes before exercise. This will be followed by four additional fluid boluses of mineral water (5 mL/kg each) administered at 120, 90, 60, and 30 minutes before exercise, for a total pre-exercise fluid intake of approximately 25 mL/kg body mass.
5-km Running Time-Trial Performance
Time required to complete a 5-km treadmill running time trial, expressed in seconds. Participants will be instructed to complete the distance as quickly as possible and will be allowed to adjust treadmill speed throughout the trial. Lower completion time indicates better performance.
Time frame: During the 5-km treadmill time trial performed after the 60-minute running preload and a 5-minute recovery period in each experimental trial.
Sweat rate
Whole-body sweat rate will be estimated from the change in body mass from immediately before exercise to completion of the 5-km time trial, adjusted for fluid intake and urine output, if applicable, and expressed as L/h. Body mass will be measured using the calibrated electronic scale integrated with the BOD POD system (COSMED, Italy) and expressed in kilograms (kg). Changes in body mass will also be calculated and reported as a percentage of pre-exercise body mass (%).
Time frame: From immediately before the 60-minute running preload to completion of the subsequent 5-km time trial during each experimental trial.
Sweat sodium concentration
Sodium concentration will be measured in sweat samples collected from standardized sites on the forearm and thigh during exercise. Sweat samples will be collected between minutes 30 and 60 of the 60-minute running preload. Sodium concentration will be analyzed using a HORIBA ion-selective electrode analyzer and reported in mmol/L.
Time frame: Between minutes 30 and 60 of the 60-minute running preload during each experimental trial.
Sweat Potassium Concentration
Potassium concentration will be measured in sweat samples collected from standardized sites on the forearm and thigh during exercise. Sweat samples will be collected between minutes 30 and 60 of the 60-minute running preload. Sweat potassium concentration will be analyzed using a HORIBA ion-selective electrode analyzer and reported in mmol/L.
Time frame: Between minutes 30 and 60 of the 60-minute running preload during each experimental trial.
Blood lactate concentration
Blood lactate concentration will be measured using a portable Lactate Scout 4 analyzer. Measurements will be obtained immediately after completion of the 60-minute running preload and immediately after completion of the subsequent 5-km time trial. Blood lactate concentration will be reported in mmol/L.
Time frame: Immediately after the 60-minute running preload and immediately after the 5-km time trial during each experimental trial.
Heart rate
Heart rate will be monitored continuously using a Garmin chest-strap heart rate monitor with integrated electrodes throughout the 60-minute running preload and the subsequent 5-km time trial. Outcome variables will include mean heart rate during the 60-minute preload, mean heart rate during the 5-km time trial, and maximal heart rate achieved during the 5-km time trial. Heart rate will be reported in beats per minute (bpm).
Time frame: Continuously during the 60-minute running preload and the subsequent 5-km time trial in each experimental trial.
Core Body Temperature
Core body temperature will be monitored continuously using a CORE body temperature sensor attached to the Garmin chest strap throughout the 60-minute running preload and the subsequent 5-km time trial. Outcome variables will include mean core body temperature during the exercise protocol and the highest core body temperature recorded during the exercise protocol. Temperature will be reported in degrees Celsius (°C).
Time frame: Continuously during the 60-minute running preload and the subsequent 5-km time trial in each experimental trial.
Running Economy
Running economy will be assessed by breath-by-breath indirect calorimetry using a QUARK RMR metabolic system during the final 10 minutes (minutes 50-60) of the 60-minute running preload. Running economy will be quantified as mean oxygen consumption (VO₂) relative to body mass at the standardized running velocity and expressed as mL·kg-¹·min-¹. Lower oxygen consumption at the same running velocity indicates better running economy.
Time frame: During the final 10 minutes (minutes 50-60) of the 60-minute running preload in each experimental trial.
Respiratory Exchange Ratio
Respiratory exchange ratio (RER) will be assessed by breath-by-breath indirect calorimetry using a QUARK RMR metabolic system during the final 10 minutes (minutes 50-60) of the 60-minute running preload. RER will be calculated as the ratio of carbon dioxide production (VCO₂) to oxygen consumption (VO₂) and expressed as a unitless value. The mean RER over the measurement period will be used for analysis.
Time frame: During the final 10 minutes (minutes 50-60) of the 60-minute running preload in each experimental trial.
Urine specific gravity
Urine specific gravity (USG) will be measured using a URIT-31 urine analyzer from urine samples collected immediately before the 60-minute running preload and after completion of the subsequent 5-km time trial. USG will be reported as a dimensionless value. Urine osmolality will also be estimated from USG using a predefined conversion equation and reported in mOsm/kg.
Time frame: Immediately before the 60-minute running preload and immediately after completion of the 5-km time trial in each experimental trial.
Rating of Perceived Exertion (RPE)
Rating of perceived exertion will be assessed using the Borg 6-20 Rating of Perceived Exertion scale, ranging from 6 ("no exertion at all") to 20 ("maximal exertion"). RPE will be recorded at 15-minute intervals during the 60-minute running preload and immediately after completion of the 5-km time trial.
Time frame: At minutes 30, and 60 of the 60-minute running preload and immediately after completion of the 5-km time trial during each experimental trial.
Thirst Sensation
Perceived thirst will be assessed using a 9-point categorical thirst sensation scale ranging from 1 ("not thirsty at all") to 9 ("very, very thirsty"). Participants will be asked to rate their current sensation of thirst at each measurement time point.
Time frame: Immediately before the 60-minute running preload, at minutes 30,and 60 of the preload, and immediately after completion of the 5-km time trial during each experimental trial.
Thermal Sensation
Thermal sensation will be assessed using a 17-point thermal sensation scale ranging from 0 to 8 in 0.5-point increments, with 0 representing "unbearably cold", 4 representing "neutral", and 8 representing "unbearably hot". Participants will rate their whole-body thermal sensation at each measurement time point.
Time frame: Immediately before the 60-minute running preload, at minutes 30 and 60 of the preload, and immediately after completion of the 5-km time trial during each experimental trial.
No study locations are listed for this record.
Plan to share: Undecided
No publications or documents are linked to this record.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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Poznan University of Life Sciences