Lifelong Exercise as a Modulator of CD4+ T Cell Immunometabolism.

BACKGROUND: It is commonly assumed that aging and chronic low-grade inflammation compromise adaptive immunity, particularly the function and metabolism of CD4+ T cells. The preceding are key regulators of immune responses. These immunological alterations contribute to increased susceptibility to infections, diminished vaccine efficacy and the progression of age-related diseases. In contrast, adolescence and young adulthood tend to be characterized by more robust immune responses, though these are heavily influenced by modifiable lifestyle factors such as habitual physical activity, level of cardiorespiratory fitness, diet and body adiposity. Emerging evidence suggests that sustained physical activity throughout life may preserve CD4+ T cell competence by favourably modulating their metabolic programming.

METHODS: The current narrative review explores how lifelong physical exercise impacts CD4+ T cell metabolism, with particular emphasis on the developmental window of adolescence and the long-term benefits of early and sustained physical training across the lifespan. Molecular mechanisms linking exercise to metabolic reprogramming of T cells were summarised in parallel with attenuation of immunosenescence and inflammation over the lifespan.

RESULTS: This review suggests that lifelong exercise may reprogram CD4+ T cell metabolism, enhancing oxidative phosphorylation at rest and glycolytic control upon activation, thereby improving Th17/Treg balance, reducing chronic inflammation and enabling effective effector T cell responses. In this context, exercise initiated early in life may act as a critical modulator by promoting optimal immune function from childhood and establishing a functional peak that helps preserve immune competence during aging.

CONCLUSIONS: Lifelong and early-life exercise may reprogram CD4+ T cell metabolism, strengthening immune balance and preserving immune function during aging.