Effects of Strength Training Combined With Sustainable Source of Omega-3 Fatty Acids on Muscle Strength and Cognitive Functions in Adults Controlled Trial

The purpose of the study is to evaluate the effects of 12-week supplementation with algae-derived DHA combined with strength training on muscle strength, neuromuscular parameters, post-exercise inflammation and cognitive functions in healthy adults compared to fish-derived EPA and DHA combined with strength training, strength training alone and control group.

The research methods and measurement tools include:

* Body composition assessed prior to the training intervention and after 12 weeks of training: body mass index (BMI) and body composition - fat mass [kg], body fat percentage [%] and skeletal muscle mass [kg] - will be determined using bioimpedance methods (In Body 720, Biospace, Seoul, Korea) following an overnight fast. * Assessment of physical activity levels using the long version of the International Physical Activity Questionnaire (IPAQ). * Assessment of mood (UMACL Adjective Mood Scale) and depression (DASS-21, Beck Depression Scale). * The SarQoL (Sarcopenia and Quality of Life) questionnaire, used to specifically assess quality of life in people with reduced muscle mass and function. * Assessment of participants' diet: each participant will be required to record their diet in 3-day food diaries (to be checked on the first day of testing). * Blood sampling: blood will be collected from each participant at two time points before and after the intervention (on an empty stomach, and 40 minutes after the training session). The following will be collected: 1 × 6 ml blood count tube and 3 tubes with a clotting activator, with a total volume of 20 ml. Blood will be collected before the start of the training intervention and after 12 weeks of training. The tubes will be centrifuged at 4 °C (4000 × g for 10 minutes). The serum, plasma and erythrocyte fractions will then be frozen at -80 °C until analysis. * Peak force, relative peak force and force at 150, 200 and 250 milliseconds during isometric mid-thigh pull-ups using a Kistler platform (Kistler dynamometer platform, model 9286BA, with MARS software). The maximum load (1RM) will also be measured for each participant. Upper limb grip strength will be measured using a SAEHAN electronic dynamometer. * In addition, muscle electrical activity using a Noraxon Telemyo surface electromyograph will be assessed. * Cognitive function will be assessed using the following tests: the Stroop Test, the Corsi Block-Tapping Task and the Pattern Separation Task.

All analysis (beside IPAQ) will be performed before and after 12 weeks of intervention.

* During the study, all participants will take part in a strength training session (around 40 mins duration) led by an experienced trainer to stimulate the muscles to release myokines. * Blood tests will include: BDNF, IGF-1, IL-6, hs-CRP, TNF-alpha, and IL-1B as well as concentrations of metabolites of the kynurenine pathway.