An interventional study of Grape seed extract in Healhty, sponsored by China Medical University Hospital. Completed at 1 site in Taiwan. Open to participants aged 20 Years to 40 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-10-09.
Sponsored by China Medical University Hospital · Not applicable, Interventional, and Other
To address the physical fatigue and muscle recovery demands in endurance exercise, this study evaluates Grape Seed Extract (GSE) as a potential ergogenic aid. The research aims to investigate whether short-term, high-dose GSE supplementation (1,800 mg/day for 7 days) prolongs cycling time-to-exhaustion (TTE) at 75% VO2max while attenuating exercise-induced muscle damage, metabolic stress, and mood disturbance in collegiate athletes. This study seeks to enhance high-intensity endurance performance and support the development of functional botanical anti-fatigue supplements.
This study employs a single-group, pretest-posttest repeated-measures intervention design involving healthy, physically active collegiate participants who habitually exercise. During the experimental period, participants are instructed to avoid any form of intensive exercise, intake of caffeinated or alcoholic beverages, or other nutritional supplements. All participants provide voluntary written informed consent. The study protocol was approved by the Human Research Ethics Committee of China Medical University Hospital (CMUH111-REC3-160, Taichung, Taiwan).
For the preliminary test, maximal oxygen uptake (VO2max) is assessed seven days prior to the pre-intervention experiment. The pre- and post-intervention trials are separated by a 28-day interval. On the experimental trial morning, participants report to the laboratory at 07:00 following an overnight fast. Participants rest for one hour following a standardized low-calorie breakfast (300 kcal) and GSE capsule ingestion before the exercise challenge. Following a 5-minute warm-up on an ergometer bike (Monark 894E, Varberg, Sweden), participants perform an exhaustive cycling exercise at 75% VO2max maintaining a pedaling speed of 60 rpm, where individual cycling time-to-exhaustion (TTE) is recorded.
Exhaustion is defined by the attainment of at least two of the following criteria: (1) a rating of perceived exertion (RPE) > 18 on the Borg 6-20 scale; (2) reaching the age-predicted maximal heart rate (220 minus age); and (3) respiratory exchange ratio (RER) > 1.10 measured by an automated cardiopulmonary gas analysis system (Vmax Encore 29c, CareFusion, Palm Springs, CA, USA).
Venous blood samples are collected at four designated time points: fasting baseline (B), pre-exercise (0), 30 minutes during exercise (30), and immediately following the exhaustive cycling exercise challenge (E) to measure concentrations of lactate dehydrogenase (LDH), creatine kinase (CK), and uric acid (UA). In addition, psychological mood states are assessed using the Profile of Mood States (POMS) questionnaire completed immediately following the TTE challenge.
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This study's enrollment of 10 is below the median of 53 across 1,479 interventional studies indexed under Fatigue.
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To approximate that cumulative exposure over a shorter period, Participants were oral 1,800 mg/day of GSE for 7 consecutive days.
Dietary Supplement: Grape seed extract
Participants were oral 1,800 mg/day of GSE for 7 consecutive days.
Cycling Time-to-Exhaustion (TTE)
Participants performed an exhaustive cycling exercise at 75% VO2max, and speed was maintained at 60 rpm on a stationary ergometer bike, where the individual maximum TTE was recorded.
Time frame: At baseline (pre-supplementation) and after 7 days of GSE supplementation (post-supplementation)
Serum Creatine Kinase (CK) Concentration
A biomarker of muscle damage measured in serum.The absorbance was measured at 450 nm, 505 nm, and 572 nm, respectively, using a microplate reader (Tecan GENios, A-5082, Austria) via enzyme-linked immunosorbent assay (ELISA), and serum concentrations were determined based on the standard curve.Unit of Measure: Units per Liter (U/L).
Time frame: Assessed at Day 8 (pre-intervention) and Day 43 (post-intervention) at four time points on each experimental day: fasting baseline (07:00), pre-exercise (after 1-hour rest), 30 minutes during cycling exercise, and immediately at exhaustion.
Lactate Dehydrogenase (LDH) Activity
A biomarker of muscle damage measured in serum using an automated clinical chemistry analyzer (Beckman Coulter AU5800).Unit of Measure: Units per Liter (U/L).
Time frame: Assessed at Day 8 (pre-intervention) and Day 43 (post-intervention) at four time points on each experimental day : fasting baseline (07:00), pre-exercise (after 1-hour rest), 30 minutes during cycling exercise, and immediately at exhaustion.
Uric Acid (UA) Levels
Measured in serum as a marker of metabolic stress and muscle damage using commercial analytical reagents. Unit of Measure: Milligrams per deciliter (mg/dL).
Time frame: Assessed at Day 8 (pre-intervention) and Day 43 (post-intervention) at four time points on each experimental day: fasting baseline (07:00), pre-exercise (after 1-hour rest), 30 minutes during cycling exercise, and immediately at exhaustion.
Profile of Mood States (POMS) - Vigor Subscale Score
A subscale of the POMS brief version used to evaluate the positive mood state of vigor. It consists of specific adjectives scored on a 5-point scale (1-5). Higher scores indicate higher levels of vigor. Unit of Measure: Units on a scale
Time frame: Assessments were conducted on Day 8 (pre-intervention) and Day 43 (post-intervention), immediately following the time-to-exhaustion (TTE) test.
Profile of Mood States (POMS) - Self-esteem Subscale Score
A subscale of the POMS brief version used to evaluate the mood state of self-esteem. Scored on a 5-point scale (1-5). Higher scores indicate higher levels of self-esteem. Unit of Measure: Units on a scale.
Time frame: Assessments were conducted on Day 8 (pre-intervention) and Day 43 (post-intervention), immediately following the time-to-exhaustion (TTE) test.
Profile of Mood States (POMS) - Tension Subscale Score
A subscale of the POMS brief version used to evaluate the negative mood state of tension. Scored on a 5-point scale (1-5). Higher scores indicate higher levels of tension. Unit of Measure: Units on a scale.
Time frame: Assessments were conducted on Day 8 (pre-intervention) and Day 43 (post-intervention), immediately following the time-to-exhaustion (TTE) test.
Profile of Mood States (POMS) - Confusion Subscale Score
A subscale of the POMS brief version used to evaluate the negative mood state of confusion. Scored on a 5-point scale (1-5). Higher scores indicate higher levels of confusion. Unit of Measure: Units on a scale.
Time frame: Assessments were conducted on Day 8 (pre-intervention) and Day 43 (post-intervention), immediately following the time-to-exhaustion (TTE) test.
Profile of Mood States (POMS) - Anger Subscale Score
A subscale of the POMS brief version used to evaluate the negative mood state of anger. Scored on a 5-point scale (1-5). Higher scores indicate higher levels of anger. Unit of Measure: Units on a scale.
Time frame: Assessments were conducted on Day 8 (pre-intervention) and Day 43 (post-intervention), immediately following the time-to-exhaustion (TTE) test.
Profile of Mood States (POMS) - Fatigue Subscale Score
A subscale of the POMS brief version used to evaluate the negative mood state of fatigue. Scored on a 5-point scale (1-5). Higher scores indicate higher levels of fatigue. Unit of Measure: Units on a scale.
Time frame: Assessments were conducted on Day 8 (pre-intervention) and Day 43 (post-intervention), immediately following the time-to-exhaustion (TTE) test.
Profile of Mood States (POMS) - Depression Subscale Score
A subscale of the POMS brief version used to evaluate the negative mood state of depression. Scored on a 5-point scale (1-5). Higher scores indicate higher levels of depression. Unit of Measure: Units on a scale.
Time frame: Assessments were conducted on Day 8 (pre-intervention) and Day 43 (post-intervention), immediately following the time-to-exhaustion (TTE) test.
Plan to share: No
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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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Studies of the drug tested here: Grape Seed Extract
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