1. Introduction
inflammation, homeostasis disorders, muscle damage
BLOOD, OXIDATIVE STRESS, LEAKAGE, INFLAMMATION
Physical exercise, especially of high intensity, is a significant burden on an athlete’s body. It should be emphasized that achieving high results in competitive sports requires the use of significant, sometimes extreme, exercise loads during training, which may result in homeostasis disorders, adversely affecting the fitness of athletes. This study aims to investigate the effects of 6 months of bovine colostrum supplementation on indicators of immune system functioning, selected parameters related to iron management, and anabolic/catabolic balance in young football players. Twenty-eight male football players completed a double-blind, placebo-controlled crossover protocol (24 weeks of colostrum/placebo). A standardized exercise test was executed at the beginning of the trial and after 3 and 6 months of supplementation. Blood samples were taken before and after the exercise test and after 3 h of recovery. Markers of iron homeostasis, pro- and anti-inflammatory balance, and hormonal responses were determined. A significant increase in immunoglobulin G concentration was observed, accompanied by a decrease in inflammatory markers in supplemented athletes. Bovine colostrum supplementation had no significant effect on athletes’ performance or on iron management and hormonal response. The use of bovine colostrum, which is characterized by a high content of immunologically active compounds, can be an element of a relatively mild and safe intervention for reducing inflammation induced by intense physical exercise.Sports activity is associated not only with a significant physical load but also with exposure to extreme conditions, like psychological stress or environmental conditions, which determine the course and the strength of adaptive reactions. Football is an intermittent sport characterized by high-intensity physical exercise, which contributes to making it highly physiologically demanding. The repetitive and eccentric characteristics of football movements (accelerating, decelerating, kicking, jumping, and attacking) can induce muscle damage accompanied by a leakage of muscle enzymes and proteins into the circulation, oxidative stress, inflammation, and a decrease in muscle performance [Supplementation with bovine colostrum (BC) has a documented immunomodulatory effect on players’ diets and may be one of the elements of a safe and gentle intervention that restores homeostasis, i.e., the balance of the immune system. There is also increasing evidence that BC may be a valuable supplement for athletes to aid in exercise performance and recovery.Bovine colostrum is the initial milk secreted by cows in the first days after delivery and contains chemical compounds with potential application in athletic performance improvement. Bovine colostrum includes, inter alia, growth factors (e.g., epidermal growth factor), antimicrobial peptides (e.g., lactoferrin), and immune mediators (e.g., immunoglobulins) that could be biologically active in humans because of their high concentrations and BC’s similarity to human colostrum [Research conducted by Kostis et al. [