The Role of Oxidative, Inflammatory and Neuroendocrinological Systems During Exercise Stress in Athletes: Implications of Antioxidant Supplementation on Physiological Adaptation During Intensified Physical Training

Abstract

During periods of intensified physical training, reactive oxygen species (ROS) release may exceed the protective capacity of the antioxidant system and lead to dysregulation within the inflammatory and neuroendocrinological systems. Consequently, the efficacy of exogenous antioxidant supplementation to maintain the oxidative balance in states of exercise stress has been widely investigated. The aim of this review was to (1) collate the findings of prior research on the effect of intensive physical training on oxidant-antioxidant balance; (2) summarise the influence of antioxidant supplementation on the reduction-oxidation signalling pathways involved in physiological adaptation; and (3) provide a synopsis on the interactions between the oxidative, inflammatory and neuroendocrinological response to exercise stimuli. Based on prior research, it is evident that ROS are an underlying aetiology in the adaptive process; however, the impact of antioxidant supplementation on physiological adaptation remains unclear. Equivocal results have been reported on the impact of antioxidant supplementation on exercise-induced gene expression. Further research is required to establish whether the interference of antioxidant supplementation consistently observed in animal-based and in vivo research extends to a practical sports setting. Moreover, the varied results reported within the literature may be due to the hormetic response of oxidative, inflammatory and neuroendocrinological systems to an exercise stimulus. The collective findings suggest that intensified physical training places substantial stress on the body, which can manifest as an adaptive or maladaptive physiological response. Additional research is required to determine the efficacy of antioxidant supplementation to minimise exercise-stress during intensive training and promote an adaptive state.

Apoptotic lymphocytes induce progenitor cell mobilization after exercise

“…Thereby, it has been shown that apoptosis in specific subtypes of lymphocytes (e.g., senescent cells) after subjects exceed a specific duration or intensity of exercise (34). It has been suggested that the expression of several potential mediators is amplified after exceeding a specific cell death-inducing threshold (13,(35)(36)(37). This threshold is assumed to be modulated by the athlete's training status, as indicated by its inverse relationship to lymphocyte apoptosis sensitivity (21).…”

Metabolic Interplay of Hepatic Enzymes – A Case Report

“…Both regular physical activity and intensive training are linked to the increase of ROS and reactive nitrogen species (RNS) production, but it was found that this mechanism is vital to the muscle's adaptation to intense physical activity [17,20]. It must be taken into consideration that improving the organism's antioxidant capacity is one of the benefits of exercise and that ROS production is presumed to activate pathways involved in regulating the endogenous antioxidant systems [17,19,21].…”

Antioxidants as therapeutics in the intensive care unit: Have we ticked the redox boxes?

“…On the other, chronic supplementation with antioxidants, contrary to the habitual practice, is increasingly acknowledged as detrimental compromising both redox and exercise adaptations [65,66]. Hence, it has been suggested that antioxidant use is a wise strategy only in situations where adaption is inconsequential and/or during short-term periods of increased exercise stress with short recovery intervals (e.g., during a tournament) [67,68].…”