Is Your Sperm A Couch Potato Too?

A paper published in the February 2013 edition of the British Journal of Sports Medicine reported the not-entirely-surprising conclusion that men who watch more TV tend to have lower sperm counts.

Harvard doctoral student and spokesman for the researchers Audrey Gaskins is quoted by the website Med Page Today as saying that men who watched the least television per week and engaged in the most physical activity had, in the Harvard story, the highest sperm counts, and men who watched the most television and engaged in the least physical activity had the lowest sperm counts.

Male Fertility Has Been a Public Health Concern for Several Decades

The Harvard study of activity and male fertility has been inspired by multiple observations that men's fertility has been on the decline all over the world since 1980, especially in the most advanced, industrialized countries. 

The most alarming studies of male fertility have come from the nation of Denmark, where, for genetic reasons, men tend to have unusually large testicles, and it is apparently relatively easy to recruit men to donate sperm samples for long-term research. (In the most recently published study, men received compensation of approximately €65 for each visit to the clinic.)

A team of researchers at the Rijkshospitalet medical center in Copenhagen collected semen samples from 4,687 men for 15 years, from 1996 to 2010.

Sperm Count Not the Only Problem in Male Fertility

These figures were actually better than averages in sperm samples collected at the hospital during World War II.

Just 23% of men in Denmark, which has some of the highest rates of male fertility in the world, are capable of becoming fathers in a 12-month period, even if their partners have no fertility issues.

Since medical scientists do not yet know how to enhance sperm quality in otherwise healthy men, they have to focus on sperm quantity. The Harvard study suggests that sperm quantity is greatly diminished in men whose lifestyle includes lots of hours in front of the TV, and couch potatoes are considerably less likely to impregnate their partners. The study makes an important point, as society continues to largely focus on women whenever fertility is discussed — but as women start taking folic acid and stop drinking alcohol, it now appears that men who want to become fathers should hit the gym.