A study published on October 6, 2025, in *Cell Metabolism* by researchers from Nanjing University and Nanjing Medical University has identified a novel mechanism for the intergenerational inheritance of exercise capacity. The research, titled "Paternal exercise confers endurance capacity to offspring through sperm microRNAs," provides the first definitive evidence that sperm microRNAs act as carriers of epigenetic information, transmitting the benefits of paternal exercise to offspring.
Historically, a robust exercise capacity was crucial for human survival, aiding in tasks such as hunting and evading predators. While modern lifestyles have shifted away from this necessity, the profound benefits of physical activity extend beyond individual health, influencing the physiological and metabolic characteristics of future generations. The study demonstrated that offspring whose fathers engaged in regular exercise exhibited superior adaptability to physical exertion and improved metabolic parameters compared to those from sedentary fathers. This effect was reproducible by injecting sperm small RNAs from exercised fathers into zygotes, establishing a direct link between paternal exercise and offspring traits.
Mechanistically, paternal exercise and enhanced muscle function lead to a remodeling of sperm microRNA profiles. These microRNAs then suppress NCoR1 in early embryos. NCoR1 is a molecule that antagonizes PGC-1α, a critical regulator of mitochondrial function. This suppression effectively reprograms embryonic development, promoting mitochondrial biogenesis and oxidative metabolism, thereby embedding enhanced endurance and metabolic resilience into the offspring's biology.
This research significantly expands the known roles of microRNAs, previously understood for intra- and interspecies signaling, to now include intergenerational communication. It suggests that sperm microRNAs can carry encoded epigenetic information derived from parental experiences and environmental exposures. The findings present a potential strategy for enhancing the health of future generations. In an era characterized by rising rates of obesity and chronic diseases linked to inactivity, paternal exercise prior to conception could improve glucose homeostasis in offspring, potentially breaking cycles of intergenerational health issues.
This work aligns with previous research indicating paternal influence on offspring health. Prior studies have shown that paternal obesity can affect offspring metabolic health through changes in sperm chromatin, and other research has demonstrated that paternal exercise can confer cognitive benefits to offspring via altered sperm RNA expression. Collectively, these findings underscore the substantial impact of paternal lifestyle choices on offspring development and health, emphasizing the importance of paternal health in reproductive planning and highlighting the potential for proactive interventions to benefit future generations.