OXIDATIVE STRESS, ANTIOXIDANT DEFENSE AND PHYSICAL ACTIVITY: BALANCE BETWEEN DAMAGE AND ADAPTATION IN AGING PROCESS

Abstract

The aging process is characterised by a gradual decline in the functional capacities of the organism, which is largely a consequence of oxidative stress - an imbalance between the production of reactive oxygen species and the efficiency of antioxidant defence. Although reactive oxygen species can damage biomolecules, in moderate amounts they act as important signalling factors that promote adaptive mechanisms and enhance cellular resistance. Physical activity represents one of the key modulators of oxidative
status because it induces a temporary increase in reactive oxygen species, thereby activating a hormetic response - an increase in the activity of antioxidant enzymes, mitochondrial biogenesis, and improvement of redox homeostasis. Regular moderate-intensity physical activity at approximately 50-70% of maximal oxygen uptake or 60-75% of maximum heart rate contributes to reducing chronic oxidative stress, slowing biological aging, and helping maintain functional independence. In contrast, high-intensity or
frequent training loads without adequate recovery may lead to the accumulation of oxidative stress and adverse effects on the body. Understanding the relationship between oxidative damage and adaptation enables the development of personalised strategies to prevent degenerative diseases and promote healthy aging.