The Impact of Physical Exercise on Male Fertility Through Its Association with Various Processes and Aspects of Human Biology.

Infertility affects approximately 10-15% couples in industrialized countries. It has numerous causes, including genetic and environmental factors, lifestyle choices, and physiological disorders. The increasing prevalence of infertility underlines the importance of research into interventions to improve reproductive health, with a strong focus on physical activity. Infertility research was traditionally mainly directed toward female health. Although the male factor is being increasingly accepted as being equally important, this area remains under-researched. The current review focuses on the impact of physical activity on male fertility through its effects on immune function, the cardiovascular system, hormonal balance, metabolism, and physical interaction with the male reproductive system. A comprehensive literature review of studies addressing the effects of physical activity on male fertility was conducted using PubMed/Medline, Scopus, and the Web of Science. Mostly recent studies were included, with a small number of older ones included in cases when their content remains relevant. The review focused on articles studying the processes involved and associations between physical activity and male fertility through immune and cardiovascular effects, endocrine modulation, the influence on obesity and insulin metabolism, and the physical impact on the body. The findings revealed the existence of a fairly strong consensus that moderate physical activity enhances semen quality, hormonal balance, and metabolic health, positively influencing male fertility. Physical activity reduces inflammation and oxidative stress, enhances cardiovascular functioning, and contributes to oxygen and nutrient supply to the reproductive organs. On the contrary, strenuous training can adversely affect fertility, mostly through hormonal disruption and oxidative stress. It can also have various indirect effects on fertility through sports-related behavior and incidents, such as wearing tight-fitting clothes or overheating. Physical activity can affect male fertility in numerous ways, positively influencing reproductive health when performed at a moderate intensity. Understanding the balance between beneficial and excessive exercise as well as the impact of incidental factors related to performing sports regularly are, thus, extremely important in optimizing lifestyle-oriented interventions aimed at male fertility improvement.