A few years ago, researchers investigating health behavior of undergraduates uncovered a mysterious positive association between exercise adherence and alcohol use. Students who drank more also exercised more frequently. A few years ago, I replicated that finding with an informal online survey that students took as part of a course I teach on the psychology of aging. I was really just interested in measuring their health habits. Sure enough, though, it was the frequent exercisers who admitted to heavier drinking patterns, including binge drinking. Of course, as we all know (and as I have pointed out in previous postings) correlation does not equal causation. Maybe students who exercise do so because they want to look good so they'll have better luck on the prowl in the weekend social scene. Or maybe heavy drinkers want to work off those extra calories by hitting the gym. Perhaps there's a third factor at work-- stress, personality, or peer pressure.
I decided to do some more investigating into the problem. You may wonder why a researcher who focuses on aging (or, as we say in the business "an aging researcher") would be interested in piercing the mentality of the average undergrad. For one thing, I worry about them because they're my students and I want them to live long and healthy lives. If you've followed some of my earlier postings, you've encountered my observation that in order to grow old you have to (drum roll, please): not die. Though heart disease is the #1 killer in the U.S., it is really the #1 killer of people who die in old age. You have to die from something and most people 65 and older die from some form of heart disease. We should worry about heart disease, of course, but we should really worry about what's killing off people prematurely. And that killer would be deaths from motor vehicle accidents, the #1 killer of young adults. Many of these deaths are alcohol related.
It's also true that moderate alcohol use is associated with lower mortality rates particularly when combined with regular involvement in aerobic exercise. Some might argue that the alcohol-drinking treadmill runners are really just trying to double their odds of living a long life. Somehow, I didn't think the answer would be quite that rational. The key here is "moderate" alcohol use, not binge drinking or even regular heavy alcohol use.
To get to the bottom of things, in work with my collaborator Catherine Sanderson of Amherst College, I've completed several surveys with undergrads. Each time, the results are the same. Exercisers drink, and drinkers exercise. I've found some interactions with personality-- in one recent analysis, the drinking-exercise relationship only appeared for people high in extraversion. The exercisers were outgoing types who liked to be around people and for the average undergrad, that meant hanging out at the local pub with their friends. In another study, we looked at the role of stress. Exercisers said they wanted to work off stress as well as excess weight, but stress didn't lead them to drink more.
When we presented these findings at a conference earlier in the year, other researchers offered their input. One psychologist suggested that the findings might not hold with older adults. To test this out, last week I posted an online survey and invited my readers to participate. I received an outpouring of responses from people ranging from 18 to 85 and up. The results confirmed what I've observed with the hundreds of college students I've already surveyed. Across age groups, there was a significant positive correlation between alcohol use and exercise frequency. Though older adults seemed more health conscious in general (they exercised more, ate food lower in fats, and so on), it was the exercisers who consumed more alcohol. And not just in moderate amounts-- some participants stated that on a typical day they consumed 5 to 7 drinks, and these were the heaviest exercisers.
Now comes the part where you think I have all the answers. The brilliant revelation that will clear up this mystery. I can't promise you that yet. But here is one suggestion that I've found pretty convincing. The "ego depletion model" of self-control, proposed by the well-known psychologist and fellow Psych Today blogger Roy Baumeister, states that engaging in one health-related behavior essentially uses up your available self-control. Exercise depletes your ability to resist drinking alcohol. It's similar to the rationalization you might have heard others make (if not yourself). "Look at how good I was today- 30 minutes on the elliptical-- I owe myself a reward. Time for a stiff martini straight up."
If the ego-depletion model solves the mystery, we're all in trouble. One rational, health-preserving behavior provides the excuse for all sorts of other health-damaging behavior. So you're going to need to shore up your mental resolve if you're going to live a long and fulfilling life. Exercise your body, exercise your mind, and then congratulate yourself for a day well-lived. And to that we can say, "salut"!
Follow me on Twitter @swhitbo for daily updates on psychology, health, and aging. Feel free to join my Facebook group, "Fulfillment at Any Age," to discuss today's blog, or to ask further questions about this posting.
Copyright Susan Krauss Whitbourne, Ph.D. 2010
French, M.T., Popovici, I. Maclean , J.C. (2009) Do Alcohol Consumers Exercise More? Findings From a national survey. American Journal of Health Promotion, 24, 2-10.
Moore, M. J., & Werch, C. (2008). Relationship between vigorous exercise frequency and substance use among first year drinking college students. Journal of American College Health, 56(6), 686-690.
Vickers, K. S., Patten, C. A., Bronars, C., Lane, K., Stevens, S. R., Croghan, I. T., et al. (2004). Binge drinking in female college students: The association of physical activity, weight concern, and depressive symptoms. Journal of American College Health, 53, 133–140