Does physical activity affect semen quality?

This study investigated if physical activity (PA) is associated with semen quality. They found that recreational PA (rPA) may improve semen quality. 

Male infertility (MI) is an increasing problem. The most common cause of MI is poor semen quality. Semen quality is determined by a number of factors. These included semen volume, sperm concentration, count and motility. Sperm morphology (shape, SMp) is also a factor in semen quality. Understanding what might affect semen quality is important in treating MI.

Physical activity (PA) is an important part of a healthy lifestyle. Many studies have investigated the effect of PA on semen quality. Both positive and negative effects have been shown. Some studies also show there is no association between PA and semen quality. These studies used various types of sports and levels of intensity. It is unclear if certain types or levels of PA are associated with better semen quality. 

This study included 32 reports of PA in men. These men underwent semen quality analysis. Both fertile and infertile men were included. PA was categorized according to type and intensity. The main categories were recreational (rPA) or elite (ePA). rPA was moderate (m-rPA) or high intensity (hi-rPA). Semen parameters were measured. These included volume, concentration, count, motility and SMp. Progressive sperm motility is when sperm swim in a straight line or large circles. 

rPA was associated with some positive effects on sperm quality parameters. Moderate rPA was associated with positive effects on semen quality and progressive motility in some studies. High-intensity rPA was associated with higher progressive sperm motility, count and concentration in some studies. In infertile men, the association between rPA and sperm concentration, count and progressive sperm motility was positive. 

Elite PA was associated with poorer sperm quality in some studies. A significantly negative effect of ePA on progressive sperm motility was observed in 3 studies. Cycling was associated with a decreased sperm concentration in several studies.

The authors concluded that rPA may improve semen quality, while elite PA might reduce semen quality.

The number of studies in this analysis was relatively low. There were a lot of differences across the studies. The effect of PA on semen quality requires more research.