1) Background: Coumestrol is a bioactive compound that inhibits HASPIN activity and prevents tau and H3 phosphorylation. Oral ingestion of CBSs increases blood testosterone levels, which decline with age causing late-onset hypogonadism. Oral ingestion of coumestrol-rich bean sprouts (CBSs) has been shown to suppress the onset of Alzheimer’s disease in 5xFAD mice and the onset of colon cancer in APCmin/+ mice. 2) Methods: We investigated the effect of oral ingestion of CBSs on the progression of aging in male senescence-accelerated prone 1 (SAMP1) mice allowed voluntary exercise or no exercise. The SAMP1 mice were divided into two groups fed either a standard diet or a diet including bean sprouts from 12 to 18 weeks of age. Each group was divided into two groups with voluntary exercise or no exercise. 3) Results: Voluntary exercise accelerated aging-related declines in blood testosterone levels, nerve growth factor levels, and spatial working memory, and oral ingestion of CBSs suppressed these age-related phenotypes, regardless of exercise. 4) Conclusion: Ingestion of CBSs prevented aging-related phenotypes in the experimental mice. A detailed analysis of the molecular mechanisms of coumestrol will be useful for understanding aging and preventing age-related diseases such as cancer, Alzheimer’s disease, and LOH.