AUTHOR=Adelowo Olayinka Emmanuel , Akindele Blessing Monica , Adegbola Cecilia Adedeji , Oyedokun Precious Adeoye , Akhigbe Tunmise Maryanne , Akhigbe Roland Eghoghosoa TITLE=Unraveling the complexity of the impact of physical exercise on male reproductive functions: a review of both sides of a coin JOURNAL=Frontiers in Physiology VOLUME=Volume 15 - 2024 YEAR=2024 URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2024.1492771 DOI=10.3389/fphys.2024.1492771 ISSN=1664-042X ABSTRACT=Regular exercise is widely recognized for its numerous physical and mental benefits, but its effects on male reproductive health are less understood. This review aims to summarize the current evidence on the impact of exercise on male reproduction, including reproductive hormone regulation, spermatogenesis sperm quality, and fertility. Moderate exercise improves sperm quality, increasing count, motility, and morphology, while excessive and severe exercise may have detrimental effects. Exercise positively influences fertility by reducing oxidative stress and enhancing sperm DNA integrity. Regular physical activity regulates reproductive hormones, including testosterone, follicle-stimulating hormone, and luteinizing hormone. Exercise-induced weight management and improved insulin sensitivity also contribute to better reproductive health. In conclusion, exercise has a profound impact on male reproductive health, with moderate physical activity promoting improved hormonal balance, sperm quality, and fertility. However, severe/excessive exercise exerts negative effects. These findings imply that a balanced exercise routine, usually mild to moderate, combined with a healthy lifestyle is essential for optimal male reproductive health. However, once exercise is severe and prolonged, it could impair male reproductive health. Further research is needed to understand the mechanisms underlying the exercise-reproduction relationship fully.