How intense exercise performed in two different training phases affects elite rowers' intestinal permeability

Background: The study aimed to check the effect of the 2000m ergometer test on the gut permeability in elite rowers in two different phases of sport training. As an inflammatory marker during the competitive phase is higher, we hypothesize that markers of intestinal permeability will also be more elevated in that phase. Methods: The study was performed during an annual preparation and competitive phase of training. Ten elite rowers of the Polish Rowing Team after applying the inclusion/exclusion criteria participated in the study. In both periods, the participants performed a 2000m ergometer test. Each time the blood samples were taken in the schedule: pre-, post-, and 1-hour post-exercise. Il-6, I-FABP, LPS, LBP, and zonulin levels were measured. Results: There were significantly lower values of I-FABP and IL-6 observed in Post-exercise time in Test II compared to Test I. The resting value of LPS was significantly lower in Test II compared to Test I. Also, resting levels of LBP and zonulin were lower in Test II, but the differences were not significant. Conclusions: Changes in gut permeability markers after extreme exercise tests may be the results of adaptive mechanisms occurring, indicating that rationally conducted training significantly decreases intestinal permeability. The ability of the gut to adapt to high levels of performance is crucial for the elite athlete.