The independent news organization of Duke University

Q&A with Dr. Erin McNamara

Exercise today can improve your sex life in old age, a recent study by Duke researchers found. According to work by Dr. Erin McNamara, a urologic resident at the Duke University Medical Center and Trinity ’00, there is a positive association between exercise and “sexual function” in men. McNamara surveyed 178 male patients of median age 62 and found that patients who regularly engaged in even very moderate exercise—like brisk walking several times a week—were at a lower risk of sexual dysfunction. The Chronicle’s Maggie LaFalce spoke with McNamara to ask about her findings.

The Chronicle: What do you think accounts for this relationship between exercise and sexual dysfunction?

Erin McNamara: We now know that erectile dysfunction can be a kind of marker of heart disease, because it’s all the same concept—small blood vessels that are supplying the penis [with blood], just like in heart disease. So if you have sexual dysfunction, you have the same kind of risk factors for heart disease. With exercise you have increased blood flow, and increased blood flow to the penis is going to increase some of those things like nitrous oxide, which helps with erections. So I think there’s that physiologic part of it, and then there’s a psychological part of it as well. I think people who exercise more feel better about themselves [and] have a better outlook, and that transfers into better sex. We controlled for age, race, [Body Mass Index], heart disease, diabetes and depression—and even with controlling for all of those things, we still saw that people who exercise more have better sexual function.

TC: Can you tell us a little bit about the conditions of the study?

EM: Patients were recruited at both the urology clinic and the internal medicine clinic and were asked to fill out two surveys. One was a sexual-function score survey, and the other was an exercise survey. The sexual function survey asked them six questions about things like ability to have an erection, ability to reach orgasm, frequency of erection and a score of how good the erections are. The exercise questionnaires asked about duration of exercise, frequency of exercise and level of activity. There’s mild, moderate or strenuous activity. Those scores are put into net hours per week, which is a pretty standard form of measuring exercise. The American Heart Association and the American College of Sports Medicine use “net hours per week” to describe exercise. You multiply the type of activity by the frequency by the duration. For example, brisk walking is given a weighted score of five, so if you were to do brisk walking 30 minutes a day, four days a week, you have ten net hours a week. Then we did linear regression and looked at sexual function scores and net hours per week, and we saw a significant association. We saw that patients who exercised nine net hours per week had a 65 percent risk reduction for sexual dysfunction.

TC: How did you become interested in this topic?

EM: I’m a urology resident at Duke, and I think it was mostly just working with my mentor, [Professor of Urology] Dr. Craig Donatucci. We see a lot of erectile dysfunction from surgery for prostate cancer. I really like the idea of treating a patient for quality of life. Obviously oncologists, their focus is quantity of life, and that’s really important too, but for me personally, I feel fulfilled in helping people with quality of life, really making sure that they’re still enjoying the life that they still have, even after cancer surgery.

TC: What impact do you think these findings have on the younger student population here at Duke?

EM: We all know that living a healthier lifestyle will be better for health in the long term. It’s hard to say, “I’m going to preserve my blood vessels in my heart,” or, “I’m doing this to prevent a heart attack in the future.” Very few people see the benefit from that right away. But we’ve shown that exercise is protective for sexual function.

TC: How much would you advise young men to exercise?

EM: In our study, it was greater than nine net hours per week. If you break it down, that’s brisk walking, four times a week, 30 minutes a day. It’s really not even that much. The American Heart Association and the American College of Sports Medicine recommend 7.5 to 12.5 net hours per week just for a healthy lifestyle. So it falls into those recommendations. We’re just saying that there are other benefits. You don’t just exercise to protect your heart, but also to protect sexual function.

TC: Do you plan to conduct further research on this topic?

EM: Definitely. I did a rat study looking at exercise. I ran little rats on treadmills, and we saw a benefit to erections in the rats. We would like to translate it into helping patients after cancer surgery to have improved sexual function. What we have right now is pharmacotherapy [like] Viagra or injection therapies. It would be nice to do something that’s not necessarily pharmacologic but more holistic.


Share and discuss “Q&A with Dr. Erin McNamara” on social media.