<p>The role of physical activity and exercise training in preventing the development of chronic disease and reducing mortality is increasingly recognized. A substantial body of evidence indicates that exercise confers these benefits to subsequent generations. This Review examines the effects of parental exercise, focusing on findings published within the past 10 years and related to mechanisms of transmission and sex-specific differences in both parents and offspring. Epigenetic modifications, including DNA methylation, histone modification and small non-coding RNAs, are crucial in how parental exercise influences offspring development. Paternal exercise alters the small RNA pool and methylation profiles in sperm, whereas maternal exercise affects both the in utero environment and postnatal lactation factors. Notably, male offspring show enhanced metabolic benefits, whereas female offspring exhibit greater cardiac improvements than male offspring. These findings highlight the sex-dependent nature of the generational effects of exercise and emphasize the need for further research into the molecular underpinnings and long-term implications for both male and female offspring.</p>