Immunomodulatory effects of Fucoidan (seaweed extract) in recreationally active adults

INTERVENTION: Daily Fucoidan supplementation for 3 weeks (3 weeks washout period between phases). One capsule, twice daily in the morning and evening. The supplement composition is as follows: Undaria pinnatifida and Fucus vesiculosus extracts (Marinova, Tasmania, Australia) containing 75.5% fucoidan. Fuicodan or placebo supplementation will commence on the day of the first sprint trial of each block (session 1, day 1) and cease the day of the last trial (session 9, day 19). Dosage: 500mg Route of administration: Oral Strategies used to monitor adherence to the intervention: Return of capsule bottle at the end of the 3‐week supplementation phase and a checklist at each testing session will be completed to ensure participants have taken the supplement each day. Supervision: Lead researcher, two research assistants, and two undergraduate student helpers. All supervisors of the sessions have accreditation with ESSA, first aid, and CPR qualification and have completed the relevant lab inductions. Mode of administration: Participants will complete the testing sessions in groups of five maximum (3 groups each testing day) together. The VO2 testing will be completed individually with supervision by two research assistants in a sports laboratory. The intensity of testing: participants will be told to complete the 6‐second sprints at maximal intensity (RPE 17‐20) Session frequency: Sessions are 3 times per week for 3 weeks (9 sessions in total) for each supplementation phase block. The sessions will take 45 minutes for completion including a warm‐up and the repeated sprint protocol. Total duration of the program: 2 x 3‐week blocks (6 weeks of exercise in total) Program adherence monitoring: Attendance will be monitored for all sess CONDITION: Immune Competence; ; Immune Competence Inflammatory and Immune System ‐ Normal development and function of the immune system PRIMARY OUTCOME: Blood samples for routine haematology and biochemistry analysis, including full blood count with white cell differential, electrolytes, measures of liver and kidney function, blood lipids, and C‐reactive protein. These collections and analyses will be outsourced to a local pathology provider.[Blood samples ( 12 ml) will be collected within 24‐48 h before the first repeated sprint testing session and 24‐48 h after the last repeated sprint testing session of each supplementation phase (a total of four samples or 5g of faecal material during a routine bowel motion. Participants will be asked to return the sample to the laboratory within 24 h of collection; samples will be stored frozen at ‐80 °C until analysis. Faecal samples will be used for determination of calprotectin, lysozyme and sIgA concentrations using commercially available immunoassay kits.[Faecal samples will be collected by the participants at their homes (via a sample pack) and brought in at the first and last repeated sprint testing session of each supplementation phase (a total of four samples). Samples are then stored in a freezer until the end of the study for analysis.] INCLUSION CRITERIA: Be male; Be aged between 18‐45 years; Have a 12 month history of regular physical activity of a minimum of 30 minutes of moderate intensity exercise per day, or the equivalent of 3.5 hours per week; 48 ml over the entire study).] In addition, saliva samples will be collected before, immediate post, and 1h following a supervised exercise session during each of the supplementation phases. Saliva samples will be collected unstimulated using eye‐spear absorbent swabs placed in the sublingual region until saturated. Eye‐spear swabs will be placed in collection tubes and stored frozen at ‐80 °C until analysis. Saliva samples will be used for the determination of lactoferrin, lysozyme, and IgA concentrations using commercially available immunoassay kits.[Saliva samples (0.5‐1mL) will be collected at the first testing session (baseline), 4th testing session (1.5 weeks post‐intervention commencement), and the final repeated sprint testing session (3 weeks post‐intervention commencement). 6 samples will be provided in total for the duration of the study.] Participants will be provided with a collection kit (consisting of flushable collection paper, collection cup with scooped lid and sealable specimen bag) and instructed to collect SECONDARY OUTCOME: During the repeated sprint testing sessions a number of measures will be recorded to track participants' performance and training adaptations during the 3 weeks supplementation blocks. One of these is the participant ratings of perceived exertion (RPE; Borg, 1982) which will be recorded at the end of each set of sprints. This is a scale 6‐20, with 6 being at rest/no exertion and 20 indicating maximal exertion.[The secondary outcome of RPE [1] will be recorded at each repeated sprint testing session. Three sessions per week for 3 weeks for the 2 supplementation phases (18 sessions in total for the duration of the study). Outcomes will be recorded in either the morning, noon, or evening at a regular predetermined time for the participants.] During the repeated sprint testing, heart rate (bpm) will be monitored continuously and recorded at the end of each 6s sec sprint effort. Heart rate will be monitored using a Garmin Bluetooth strap fitted around the chest of the participant and connected to a watch for visual display.[The secondary outcome of peak and mean power [3] will be recorded at each repeated sprint testing session. Three sessions per week for 3 weeks for the 2 supplementation phases (18 sessions in total for the duration of the study). Outcomes will be recorded in either the morning, noon, or evening at a regular predetermined time for the participants.] During the repeated sprint testing, peak (W) and mean power output (W) will be recorded after each 6s sprint effort. After each sprint, the values are displayed on a summary screen on the watt bike and will be recorded by a research assistant before the next sprint repetition begins.[The secondary outcome of peak and mean power [2] will be recorded at each repeated sprint testing session. Three sessions per week for 3 weeks for the 2 supplementation phases (18 sessions in total for the duration of the study). Outcomes will be recorded in either the morning, noon, or evening at a regular predetermined time for the participants.]