Chronic Grape Extract in Crosstraining Athletes: A Randomized Crossover Trial

Not Applicable

Not yet recruiting

• Conditions: Performance

• Registration Number: NCT07106281
• Lead Sponsor: Universidad de Granada

Brief Summary

The aim of this study is to investigate the effect of cronic GSE intake in crosstraining may have a favorable impact on biochemical markers, recovery, and performance.

Detailed Description

Supplementation with certain antioxidant nutrients is a feasible strategy to accelerate recovery from fatigue and prevent exercise-induced oxidative damage. Grape seed extract (GSE) contains flavonoids such as proanthocyanidins, which are potent antioxidants with numerous health benefits. Therefore, optimizing the recovery process after training is essential for athletes engaged in strength and power sports who aim to enhance performance.

Thirty trained CrossFit athletes consumed grape seed extract or a placebo for one week. The training session consisted of a 12-minute strength block, a 13-minute metabolic conditioning (MetCon), and a final 15-minute MetCon. The Rating of Perceived Exertion (RPE), Gastrointestinal Distress Score (GDS), blood pressure and the Perceived Recovery Status scale (RPS) were administered at the beginning of the session and at the end of each segment of the CrossFit session. DOMS was assessed using a visual analog scale at 24 and 48 hours after the CrossFit session.

Study Timeline

• Status Verified: 2025-07
• Study First Submitted: 2025-07-21
• Study First Submitted QC: 2025-07-29
• Last Update Submitted: 2025-07-29
• Study First Posted: 2025-08-06
• Last Update Posted: 2025-08-06
• Study Start: 2025-09-01
• Primary Completion: 2025-12-20
• Study Completion: 2026-01-31

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: Male
• Target Recruitment: 30

Inclusion Criteria

• Age: 18-35 years.
• Body mass index: 18.5-30 kg/m2.
• Ability to understand the instructions, objectives, and study protocol.
• Minimum of 3 years of experience in crosstraining, with at least 6 hours of weekly training over the past 3 months.
• Resident on the island of Tenerife.

Exclusion Criteria

• History of a significant adverse cardiovascular event, renal insufficiency, cirrhosis, eating disorder, weight control surgical intervention, or type 2 diabetes mellitus.
• Any chronic pathology in which the intake of nutritional supplements, especially use of antioxidant supplements during the 4 weeks prior to the start of the study.
• Any condition that, in the investigator's judgment, would impair the ability to participate in the study or represent a personal risk to the participant.
• Use of medications that may affect the study results.
• Unstable body weight for 3 months prior to the start of the study (> 4 kg loss or gain in weight).
• Active tobacco abuse or illicit drug use, or history of treatment for alcohol abuse.
• On a special diet or prescribed for other reasons (e.g., celiac disease).

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Primary Outcome Measures

Name	Time	Method
Performance	60 minutes	Deep squat test at 70% of repetition maximum

Secondary Outcome Measures

Name	Time	Method
Attention	60 minutes	Selective attention and inhibitory control measured by the Stroop test
Performance: Weight used in the crosstraining session	60 minutes	Weight used in the crosstraining session
Performance: Time performed in the crosstraining session	60 minutes	Time performed in the crosstraining session
Subjective fatigue throug the the RPE scale	60 minutes	Rate of perceived exertion scale
Gastrointestinal distress	60 minutes	Gastrointestinal distress through the Gastrointestinal Distress Score (GDS)
Biochemical parameters	48 hours	Biochemical parameters of muscle damage: Glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT), creatine kinase (CK), urea, lactate dehydrogenase (LDH), myoglobin, glutathione peroxidase (GPx), catalase, superoxide dismutase (SOD), and interleukin 6 (IL-6)
Recovery	60 minutes	Perceived Recovery Status Scale (RPS)
Delayed-onset muscle soreness (DOMS)	24 hours	Delayed-onset muscle soreness (DOMS) scale (0-10 arbitrary units)
Capillar lactate levels	60 minutes	Capillar lactate levels
Heart rate	60 minutes	Heart rate
Blood pressure	60 minutes	Blood pressure

Trial Locations

Locations (1)

Universidad de la Laguna; 🇪🇸 Santa Cruz De Tenerife, Spain