WEDNESDAY, Oct. 19 (HealthDay News) -- Men who get moderate amounts of exercise have better sperm motility than men who are less or more physically active, a new study finds.

Motility refers to the sperm's ability to swim and move towards an egg, an important factor in fertility.

The study by researchers at Yamaguchi University in Japan included 215 men who provided semen samples and information about their physical activity levels. The men were divided into three groups: strenuous, moderate or light exercise. Age and body mass index were similar among the three groups.

The moderate-exercise group had the highest average sperm motility and the fewest men with less than 40 percent sperm motility (14.3 percent), while 31 percent of those in the light-exercise group and 27 percent of those in the strenuous-exercise group had less than 40 percent sperm motility.

The study was slated for presentation Wednesday at the annual meeting of the American Society for Reproductive Medicine in Orlando.

"Exercise is a component of an overall healthy lifestyle which contributes to reproductive health. This study, which uses frequency, intensity and duration to quantify the amount of exercise a subject gets, shows that a moderate exercise routine may be recommended to modestly improve semen parameters in men with no known conditions that impair their reproductive capacity," ASRM president-elect Dolores Lamb said in a society news release.

Because this study was presented at a medical meeting, the data and conclusions should be considered preliminary until published in a peer-reviewed journal.

More information

The U.S. National Library of Medicine has more about sperm.