Cognitive Function, Physical Performance, Sports Nutrition
Conditions
Keywords
Omega-3 fatty acids, Physical performance, Randomized controlled trial, Erythrocyte membrane fatty acids, Sports nutrition
Brief summary
The aim of this study is to evaluate the effects of omega-3 fatty acid supplementation on the Omega-3 Index, erythrocyte membrane composition, cognitive function, hormonal profile, speed, endurance performance, and hematological parameters in competitive athletes aged 16-35 years.
Detailed description
Skeletal muscle function, including the ability to generate force, sustain repeated high-intensity efforts, and resist fatigue, is essential for soccer performance. In addition to neuromuscular adaptations, increasing evidence suggests that nutritional interventions, particularly omega-3 fatty acid supplementation, may influence muscle function, recovery, inflammation, and cognitive performance. However, despite growing interest in omega-3 fatty acids, evidence regarding their effects on physical and cognitive performance in competitive soccer players remains limited. The present randomized, placebo-controlled trial aims to evaluate the effects of four weeks of high-dose omega-3 fatty acid supplementation in competitive male soccer players aged 16 to 35 years. Participants will continue their regular soccer training and maintain their habitual mixed diet throughout the study. The primary objective is to determine the effects of supplementation on the Omega-3 Index and the erythrocyte fatty acid profile, including omega-3, omega-6, trans fatty acids, and arachidonic acid (AA). In addition, the study will evaluate changes in cognitive function, hormonal profile, speed and endurance performance, hematological parameters, lipid profile, inflammatory markers, oxidative-antioxidant status, and erythrocyte membrane composition. The fatty acid profile will be assessed using a validated laboratory method that enables quantitative determination of individual fatty acids in erythrocyte membranes, providing an objective biomarker of long-term omega-3 status and membrane lipid composition. This approach allows comprehensive evaluation of the biological response to omega-3 supplementation in competitive athletes. The findings of this study are expected to improve understanding of the physiological effects of high-dose omega-3 fatty acid supplementation in soccer players and may contribute to evidence-based nutritional strategies aimed at optimizing health, recovery, cognitive function, and athletic performance.
Interventions
DIETARY_SUPPLEMENTEPA + DHA supplements
Participants will randomly assigned to the supplemented group. The supplement will be administered in a dose of 4 capsules twice a day for 4 weeks. Daily dose will contain 3500mg EPA + DHA
DIETARY_SUPPLEMENTPlacebo
Participants will randomly assigned to the Placebo group. The placebo will be administered in a dose of 4 capsules twice a day for 4 weeks. Daily dose will contain 3500mg MCT.
Sponsors
The Jerzy Kukuczka Academy of Physical Education in Katowice
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
DIAGNOSTIC
Masking
DOUBLE (Subject, Investigator)
Intervention model description
Participants were randomly assigned to either the omega-3 supplementation group or the placebo group. Both groups were followed in parallel throughout the 4-week intervention period while maintaining their regular training program and habitual diet.
Eligibility
Sex/Gender
ALL
Age
16 Years to 35 Years
Healthy volunteers
Yes
Inclusion criteria
\*\*Inclusion Criteria:\*\* * Male competitive soccer players aged 16-35 years. * Regular participation in organized soccer training and competition. * A minimum of 6 years of systematic soccer training experience. * Participation in regular team training during the study period. * Habitual mixed diet. * Ability and willingness to maintain usual dietary habits and training load throughout the 4-week intervention. * Written informed consent provided by the participant. * For participants under 18 years of age, written informed consent provided by a parent or legal guardian and assent provided by the participant. \*\*
Exclusion criteria
\*\* * Current use of omega-3 fatty acid supplements or fish-oil products. * Use of omega-3 supplements within the 3 months preceding enrollment. * Known allergy or hypersensitivity to fish, seafood, fish oil, or any ingredient of the study supplements. * Diagnosed cardiovascular, metabolic, endocrine, gastrointestinal, neurological, inflammatory, autoimmune, or hematological disease. * Acute infection, injury, or illness that could affect participation in training or study assessments. * Use of medications or dietary supplements that could influence lipid metabolism, inflammatory status, hormonal profile, blood coagulation, cognitive function, or physical performance. * Regular use of anticoagulant or antiplatelet medication. * Significant change in diet, training volume, or supplementation during the study period. * Failure to comply with the supplementation protocol or attendance requirements. * Participation in another clinical or nutritional intervention study during the study period.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in Omega Index | From enrollment to the end of 4-week supplementation | The Omega-3 Index will be assessed in erythrocytes as the combined percentage of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) relative to total fatty acids in erythrocyte membranes. Blood samples will be collected at baseline and after the 4-week supplementation period. In addition to the Omega-3 Index, the erythrocyte fatty acid profile, including individual omega-3 and omega-6 fatty acids, arachidonic acid (AA), and trans fatty acids, will be assessed. Changes from baseline to the end of the 4-week intervention will be evaluated. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Neuromuscular function | From enrollment to the end of supplementation period of 4 weeks | Neuromuscular function was assessed using tensiomyography (TMG), a non-invasive method for evaluating the contractile properties of skeletal muscles. Parameters including contraction time (Tc), delay time (Td), sustain time (Ts), relaxation time (Tr), and maximal radial displacement (Dm) were measured at baseline and after the 4-week intervention. |
| Hematological parameters and hormones | From enrollment to the end of supplementation period of 4 weeks | Hematological parameters were assessed using fasting venous blood samples. Outcome measures included complete blood count variables, including red blood cell count, white blood cell count, hemoglobin, hematocrit, platelet count, and red blood cell indices. Also testosteron and cortisol concentration was measured. Changes from baseline to the end of the 4-week intervention were evaluated. |
| Lipoprteine profile | From enrollment to the end of supplementation period of 4 weeks | The lipoprotein profile was assessed using fasting blood samples. Outcome measures included total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides. Changes from baseline to the end of the 4-week intervention were evaluated. |
| Cognitive function | From enrollment to the end of supplementation period of 4 weeks | Cognitive function was assessed using the Corsi Block-Tapping Test, which evaluates visuospatial working memory, short-term memory capacity, and executive cognitive performance. Changes in test performance were compared between baseline and the end of the 4-week intervention. |
| Speed on 5 and 30m | From enrollment to the end of supplementation period of 4 weeks | Running times will be recorded using two pairs of dual-beam Witty Gate photocells (Microgate, Bolzano, Italy), a valid and reliable system for sprint performance assessment. Following a standardized warm-up, participants will perform two maximal 30-m sprint trials on an indoor artificial grass surface, with 15 minutes of passive recovery between trials. To prevent premature activation of the timing system, participants will start with the leading foot positioned 0.5 m behind the first timing gate. Split times at 5 m and 30 m will be recorded automatically, and the best performance from the two trials will be used for statistical analysis. |
| Anaerobic performance | From enrollment to the end of supplementation period of 4 weeks | Anaerobic performance will be assessed using the Running-Based Anaerobic Sprint Test (RAST). Following a standardized warm-up, participants will perform six maximal 35-m sprints separated by 10 seconds of passive recovery. Sprint times will be recorded using an electronic timing system. Peak power, mean power, minimum power, fatigue index, and total sprint time will be calculated according to the standard RAST protocol. All tests will be performed under standardized environmental conditions, and participants will receive standardized verbal encouragement throughout the test. |
| CMJ performance | From enrollment to the end of 4-week supplementation | Countermovement jump performance will be assessed using dual force plates (ForceDecks, VALD Performance, Australia), a validated system for quantifying vertical jump kinetics and kinematics. Before testing, participants will stand quietly on the force plates for 3 seconds to determine body mass and baseline force. The testing protocol will include bilateral countermovement jumps with arm swing (CMJa) and unilateral countermovement jumps performed separately on the dominant and non-dominant limbs. Participants will perform a rapid countermovement followed immediately by a maximal vertical jump. Three maximal trials will be completed for each test, with 1 minute of passive recovery between bilateral trials and 30 seconds between unilateral trials. The best trial for each test will be retained for analysis. Vertical ground reaction force data will be sampled at 1000 Hz and analyzed using the manufacturer's software. Outcome measures will incl |
| Change in Reactive Strength and Leg Stiffness | From enrollment to the end of 4-week supplementation | Reactive strength and lower-limb stiffness will be assessed using the Myotest Pro system during three consecutive maximal plyometric jumps. Outcome measures will include reactive strength index (RSI) and leg stiffness. Changes from baseline to the end of the 4-week intervention will be evaluated. |
Countries
Poland
Contacts
CONTACTMałgorzata Magdalena Michalczyk, Professor
CONTACTGrzegorz Henryk Zydek, assistante profesor
STUDY_DIRECTORMałgorzata M Michalczyk, Proffesor
Institute of Sport Sciences, Jerzy Kukuczka Academy of Physical Education in Katowice
Outcome results
None listed