PHYSICAL ACTIVITY AND INACTIVITY AS FACTORS THAT INFLUENCE IMMUNE STATUS

Olga BULAT,Universitatea de Stat din Moldova

Abstract

The article analyzes the impact of physical activity and sedentary lifestyle on the homeostasis of the immune system. The results indicate that moderate intensity physical exercise exerts an immunomodulatory effect, optimizing leukocyte dynamics (lymphocytes, neutrophils, NK cells) and stimulating the secretion of anti-inflammatory myoki- nes (IL-13). At the same time, physical activity regulates the hypothalamic-pituitary-adrenal axis, causing a reduction in cortisol levels and attenuation of immunodeficiencies induced by psychophysiological stress. Acute adaptations, such as transient leukocytosis, are demonstrated to be essential mechanisms for maintaining homeostasis and tissue regeneration. Furthermore, prolonged physical inactivity (hypodynamia) is defined as a systemic proinflammatory stress factor, correlated with the upregulation of proinflammatory cytokines (TNF-α, IL-6, IFN-γ) and the activation of pathological signaling pathways in T-cell populations (CD4+ and CD8+). Sedentary behavior favors the develop- ment of sarcopenic obesity, alteration of the microbiome, and increased vulnerability to viral or bacterial infections, as a result of compromising immunological memory and NK cell function. Keywords: physical activity, physical inactivity, sedentarism, hypodynamia, immune cells, lymphocytes, leuko- cytes, hypothalamic-pituitary-adrenal axis.

DOI: https://doi.org/10.59295/sum1(191)2026_11