Exercise Fights All 14 Hallmarks of Aging at the Molecular Level

As the global population aged 60+ approaches 2.1 billion by 2050, the burden of age-related diseases — cancer, cardiovascular disease, neurodegeneration, diabetes — demands scalable, accessible interventions. This landmark 2025 review by Qiu, Fernández-García, Kroemer, López-Otín, and colleagues provides the most comprehensive mapping to date of how exercise mechanistically counters the 14 hallmarks of biological aging, updated to include newer hallmarks such as extracellular matrix changes, dysbiosis, and psychosocial isolation.

On the genomic front, 14–16 weeks of moderate resistance exercise reduced urinary 8-hydroxy-2'-deoxyguanosine (oxidative DNA damage marker) in adults over 60, while combined strength-aerobic programs decreased DNA strand breaks in peripheral blood lymphocytes of 40–74-year-olds. Long-term Tai Chi practitioners showed lower DNA damage and reduced sister chromatid exchange frequencies. Exercise also attenuates mitochondrial DNA mutation rates and promotes mtDNA biogenesis via PGC-1α signaling. Telomere biology is similarly improved: aerobic exercise increases telomerase activity (TERT expression) and is associated with longer leukocyte telomere length in observational cohorts. Epigenetically, exercise modulates DNA methylation age clocks (reducing biological age estimates), alters histone acetylation, and regulates aging-relevant non-coding RNAs including microRNAs.

Proteostasis and autophagy — critical for clearing damaged proteins — are both enhanced by exercise. Endurance training upregulates autophagy flux through AMPK and mTOR pathway modulation, and resistance exercise supports the ubiquitin-proteasome system. Nutrient-sensing deregulation, a central driver of aging, is reversed: exercise restores insulin sensitivity, activates AMPK, and suppresses hyperactive mTORC1. Mitochondrial dysfunction — perhaps the most studied exercise-aging nexus — is countered through increased mitochondrial biogenesis, improved oxidative phosphorylation efficiency, enhanced mitophagy, and reduced ROS production.

Cellular senescence burden is reduced by exercise through both clearance of senescent cells and dampening of the senescence-associated secretory phenotype (SASP), lowering systemic inflammatory tone. The extracellular matrix, which stiffens and undergoes pro-fibrotic remodeling with age, is favorably influenced by mechanical loading from exercise. Stem cell exhaustion in muscle (satellite cells), bone marrow, and neural compartments is partially reversed by physical training. Intercellular communication — including exosome and cytokine signaling — is modulated by exercise-induced factors (exerkines). Chronic low-grade inflammation ('inflammaging') is consistently reduced by regular moderate PA. Gut microbiome diversity, which declines with age, improves with aerobic exercise, correlating with better metabolic and immune profiles. Finally, the review uniquely addresses psychosocial isolation as a hallmark, noting that group exercise programs improve social connectedness and mental health in older adults.

The authors note that as little as 15 minutes of daily PA reduces all-cause mortality by 14% and adds ~3 years of life expectancy, while meeting full WHO guidelines (150–300 min moderate or 75–150 min vigorous weekly) yields a 31% mortality reduction. They emphasize personalization of exercise prescriptions for older adults and call for future research to define minimum effective and maximum safe exercise thresholds in aging populations.