Couch Potatoes' Sperm Counts Lower

Sperm counts lower in heavy TV watchers but higher in big exercisers

(RxWiki News) While you're lazily flipping channels on the remote, your sperm may be lazing about as well. But get up and exercise, and your sperm may get up and going too.

Those are the findings of a new study that found a link between how active young men are and their sperm counts.

The men who watched the most TV had the lowest sperm counts. The men who exercised the most had the highest sperm counts.

Neither watching TV nor exercising seemed to make a difference about the quality of the sperm, though.

"Watch TV less, exercise more."

The study, led by Audrey Jane Gaskins, a PhD student in the Departments of Nutrition and Epidemiology at Harvard School of Public Health, looked for whether there was a link between time spent watching television and healthy young men's sperm counts.

The researchers gave detailed questionnaires to 189 men, aged 18 to 22, that asked about the men's physical activity and TV watching habits over the previous three months.

Then the men's sperm was analyzed to find out their sperm count and the quality of the sperm.

The researchers found that both TV time and exercise made a difference in the the concentration of sperm the men had in their semen.

The men who spent at least 15 hours a week doing moderate-to-vigorous exercise had 73 percent higher sperm counts than those who were least active.

That means the very active men had 73 percent more individual sperm in their semen than the men who spent less than five hours a week doing moderate or vigorous physical activity.

Meanwhile, the more often men watched TV, the lower their sperm counts were. Men who watched more than 20 hours a week of television had 44 percent lower sperm counts than the men who watched no television at all.

The researchers did not find any connection between the quality of the men's sperm (shape, speed, etc.) and the time they spent watching TV or exercising.

Similar results showing a connection between sperm counts and activity levels had previously been shown in lab animal tests.

"Our findings suggest that a more physically active lifestyle may improve semen quality," the researchers wrote.

The bottom line: if you want to improve your sperm count, swap some TV time for time on the bike, taking a jog, swimming, playing a sport or some other vigorous activity.

The study was published February 4 in the British Journal of Sports Medicine. The research was funded by the National Institutes of Health and the European Union DEER Grant. The authors declared no conflicts of interest.

Review Date: 
February 6, 2013