Effect of 8-week Supplementation With Anthocyanin Compounds Contained in Black Chokeberry on Inflammation and Oxidative Stress Induced by Very Intense Exercise in Highly Trained Rowers

Participants Twenty participants from the Youth National Rowing Team of Poland have been recruited for the study. In the end, fifteen rowers participated in the study (two did not show up for the first date, three more were absent for the second date). Before the first and second dates of the study, a body composition analysis was performed using the TANITA MC-780 with an accuracy of 0.05 kg, and hight was measured throughout sea 217 hightmeter. The experiment was conducted in accordance with the Declaration of Helsinki. The study protocol was approved by the Ethical Committee of the Medical University of Poznan (resolution no. 390/22). All players were informed of the exact course of the study and gave written consent to participate.

Youth National Rowing Team of Poland The athletes' diets were completely analyzed before each exercise test by a nutritionist. Participants, with the help of a dietician who was available during meals on test days, filled out food diaries. The amount of energy, protein, carbohydrates, fats and fiber were then analyzed using a commercially available program.

Experimental procedure The rowers were randomly divided into two groups-supplemented and control, it was a double-blind study. Athletes in the supplemented group (n=7) consumed capsules with highly concentrated 18% chokeberry extract. One capsule contained 200 mg. In addition to chokeberry extract, each capsule also contained chokeberry fiber, E460b magnesium salts of stearic acid (anti-caking agent), E551 silicon dioxide (anti-caking agent), hydroxypropyl methylcellulose (capsule shell) and E171 titanium dioxide (shell color). The control group (n=8) consumed capsules that were made from chokeberry fiber. All additional substances the same as in capsules with chokeberry extract. The supplement and placebo product was manufactured by MBL BIOTRADE, Poznań. The rowers (both supplemented and control group) took 3 capsules a day (at breakfast, lunch and dinner) for 8 weeks. The athletes sipped each capsule with a glass of water.

Exercise test On two testing dates (before and after supplementation), the athletes performed a 2,000-meter test on a rowing ergometer (Concept II, USA). Athletes had to complete the test in the shortest possible time overcoming the maximum load. The results of the test were taken into account in the selection for the championship team so the athletes performed the task with great motivation. Before the test, each competitor individually performed a 5-minute warm-up.

Material collection and examination Samples were taken at three time points: pre (before the exercise test) post (immediately after the exercise test and 1 hour after) and recovery (24 hours after the exercise test) both before and after the supplementation period. Blood samples were collected from the elbow vein into 9-ml tubes (to obtain serum) and centrifuged at 3,000 rpm and into 2.7-ml tubes (to determine morphology). Morphology was determined on the same day the samples were collected, while serum was frozen and stored at -80oC until assays were performed. In addition, before and immediately after the exercise test, capillary blood was drawn from the earlobe to determine lactate levels.