When you’ve had a tiring day at work and Netflix beckons as you walk through the door, it’s a struggle to find the motivation to exercise. Don’t give in to the temptation to hit the sofa for the night because new research cautions that too much TV – and too little activity – could spell trouble for your fertility.
Known as The Rochester Young Men’s Study, the research draws on semen samples collected by a team from our own University of Rochester Center for Reproductive Epidemiology (based out of URMC’s OB/GYN Department). Young men from all over the Rochester area submitted samples and questionnaires probing their level of physical activity, diet, stress, and other lifestyle factors. (Our Rochester team then collaborated with colleagues at Harvard, who ultimately published the findings that are now making headlines nationally.)
To put the insights into perspective, our sister URMC blog, Scripts, spoke with Dr. Emily Barrett, a reproductive epidemiologist who works in the research group that conducted the study. We offer that interview here:
Scripts: Sperm counts have been in free-fall for decades. Can you tell us why this might be?
Barrett: There’s actually some controversy as to whether sperm counts truly are declining across the globe. But, if they are, it’s likely linked to a number of underlying factors, not any one particular thing. It could be that environmental chemicals play a role; we’re starting to realize that diet and lifestyle choices might be important, too.
Scripts: That’s a big theme, apparently, in this study. The results suggest that two modifiable factors – exercise and TV watching – could be tied to sperm count. But the paper throws around some downright impressive stats – for instance, the big-exercisers enjoyed “a 73 percent boost in sperm count.”
Barrett: To put that in context, the average man has 15 to 20 million sperm per milliliter. That’s what’s considered normal. Go lower than that, and successful conception is less likely.
While we don’t know the mechanism behind the relationship found in the study, there are several hypotheses as to why sperm counts might be higher or lower, given these variables. The study authors speculate that increased antioxidant production, which is often linked with exercise, might actually be protective against the routine stress and cell damage that ultimately hinders sperm production. Yet another hypothesis is that the physical act of being scrunched up while sitting on the couch could lead to a higher scrotal temperature – and, consequently, less sperm. But it’s also entirely possible that exercise and TV watching are red herrings, and sperm production is actually associated with other underlying behaviors or factors that the researchers didn’t measure.
Scripts: Good point. What should men take away from this research?
Barrett: We have to be careful not to read too much into these results (this is the first study of its kind). Even so, this is yet another reason for men to get off the couch and exercise.
We know of several other lifestyle factors that are likely to affect sperm quality or quantity. Smoking, being overweight, and prolonged bicycling all may lower sperm counts. Many health conditions can also affect production, so staying in good general health will help to protect men’s fertility as well. It’s really important for men to realize that their lifestyle choices not only affect their general health, but also their fertility.
Emily S. Barrett, Ph.D., is an assistant professor in the Department of Obstetrics and Gynecology at URMC.