Why Fitter People Drink More Alcohol

My second-favorite running T-shirt quote is usually attributed to the versatile New Zealander Rod Dixon, whose range stretched from an Olympic medal in the 1,500 meters to a New York City Marathon victory: “All I want to do,” he said, “is drink beer and train like an animal.” (My favorite is from Noureddine Morceli: “When I race, my mind is full of doubts. Who will finish second? Who will finish third?”) I don’t even like beer all that much, but there’s something appealing in the simple clarity of Dixon’s ambitions—something, it turns out, that seems to resonate with a lot of runners.

Many different studies over the years have concluded that people who exercise a lot also tend to drink more. This is mildly surprising, because in general healthy or unhealthy behaviors tend to cluster together: exercise buffs are less likely to smoke but more likely to eat a lot of kale, for example. Admittedly, alcohol is tricky to slot into the “healthy” or “unhealthy” category because there’s (much debated) evidence that light or even moderate drinking may confer some health benefits. But I don’t think Dixon’s taste for beer was driven by a desire to lower his blood pressure.

A study in Medicine & Science in Sports & Exercise, from a research team at the Cooper Institute in Dallas, offers a new perspective on the exercise-alcohol link. Many of the previous studies have focused on competitive athletes, particularly on college teams, where high levels of alcohol consumption may reflect frat-like social pressures rather than an intrinsic desire to drink. But the new study looks instead at data from 38,000 healthy patients ranging in age from 20 to 86 who underwent preventive testing at the Cooper Clinic—and it too finds a strong link between exercise and alcohol habits.

The subjects’ cardiorespiratory fitness (i.e. VO2 max) was estimated with a treadmill test to exhaustion. Based on those results, they were divided into five equal groups based on their age- and sex-adjusted scores, with the lowest group classified as low fitness, then next two as moderate fitness, and the highest two as high fitness. For alcohol consumption, those consuming three or fewer drinks per week were considered light drinkers; up to seven for women and 14 for men was moderate; and above that was heavy.

The main result was that moderately and highly fit people were far more likely to be moderate or heavy drinkers than less fit people. For women, being highly fit more than doubled the odds of being a moderate or heavy drinker. For men, it increased the odds by 63 percent. These subjects, for the most part, were neither college rowdies nor elite athletes. The average age was 45.9, and the threshold for high fitness among men was a VO2 max of 46.9 ml/kg/min, which is good but won’t win any races. VO2 max and exercise habits aren’t perfectly correlated, since genetics affects VO2 max, but a sub-analysis using the subjects’ self-reported workout habits instead of VO2 max scores found a similar pattern.

The interesting question is why there’s an association between exercise and drinking. The paper’s authors cautiously suggest that the former may cause the latter, perhaps due to a psychological phenomenon called the licensing effect: when you feel like you’ve done something “good,” you reward yourself by allowing yourself to do something “bad.” (For the record, that’s one of the reasons I’m skeptical of the idea of taking multivitamins as insurance against gaps in your diet: the act of taking a vitamin unconsciously gives you permission to create those gaps.) There is, indeed, a bit of evidence that people tend to drink more on days when they’ve exercised more than usual.

But there’s another school of thought that suggests both exercise and alcohol use are influenced by the same set of personality traits. A 2014 study from University of Houston researcher Leigh Leasure, for example, linked both exercise and drinking behavior to higher levels of sensation-seeking—a trait that, in turn, is influenced by how your brain’s reward circuitry processes dopamine. In subsequent work, Leasure and her colleagues define four distinct motivations for coupling exercise and alcohol, which they dub work hard-play hard, celebration, body image, and guilt. In the former two, exercise leads to drinking; in the latter two, drinking leads to exercise.

So does running turn you into an alcoholic, or save you from becoming one? You can argue it both ways—that exercise might reinforce the reward-seeking behavior that leads people to drink to excess, or that it might compete with and displace the need to drink. There are certainly plenty of narratives out there about former addicts who’ve become ultrarunners and who credit it with saving their lives.

Interestingly, the Cooper Clinic study also administered a questionnaire designed to assess alcohol dependence in its subjects. Overall, 13 percent of the subjects met the threshold for alcohol dependence, based on their answers to questions about whether they were trying to reduce their drinking, got annoyed by criticism about it, felt guilty about it, or drank first thing in the morning. Among heavy-drinking men (though not women), the fittest were the least likely to exhibit signs of dependence. This fits with the idea that their exercise habits are filling some of the psychological space that alcohol might otherwise fill on its own.

This is clearly a topic that’s going to resist broad generalizations and simple truths. Leasure’s work emphasizes the role of individual personality characteristics and social factors in mediating the links between exercise and alcohol. For those of us with a heavy streak of sensation-seeking, it’s worth keeping those links in mind—and when in doubt, keep training like an animal.

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