Fit and Tipsy?

The Interrelationship Between Cardiorespiratory Fitness and Alcohol Consumption and Dependence

Kerem Shuval; David Leonard; Karen G. Chartier; Carolyn E. Barlow; Bob M. Fennis; David L. Katz; Katelyn Abel; Stephen W. Farrell; Andjelka Pavlovic; Laura F. Defina

Disclosures

Med Sci Sports Exerc. 2022;54(1):113-119. 

In This Article

Discussion

In the present study, we assessed the interrelationships between fitness and alcohol consumption and dependence among patients presenting at a preventive medical clinic. Study findings indicate that current drinkers with higher fitness levels exhibited an increased tendency for alcohol consumption. For example, highly fit women and men were ~2.1 and ~1.6 times, respectively, more likely to be moderate/heavy versus light drinkers in comparison to low fit women and men. When examining self-reported physical activity (rather than fitness) as the exposure, analysis showed similar patterns when comparing moderate/heavy versus light drinking across physical activity levels. These trends appear to reflect tradeoffs primarily between light and moderate drinking; heavy drinking was largely unchanged.

Previous research in the field has observed similar findings with regard to physical activity and alcohol consumption. For example, Werneck et al.[50] observed that Brazilian adults with higher levels of physical activity were more likely to consume alcohol on a weekly basis. In fact, a systematic review by Dodge et al.[51] concluded that three fourths of studies among nonstudent adults found that higher levels of physical activity were related to increased alcohol consumption. Although many of the reviewed studies were cross-sectional, limiting the ability to determine a temporal relationship, Conroy et al.[52] examined physical activity and drinking patterns over a 21-d period, finding that individuals consumed more alcohol on the same days when they were more physically active. Thus, present results, alongside prior evidence,[51] indicate that those engaging in physical activity are also more likely to consume alcohol, although not necessarily at a level that exceeds drinking guidelines. This relationship could be explained by a psychological mechanism referred to as the "licensing effect," where achieving goals (e.g., running a 10-km race) could provide a "license" to indulge in an unhealthy behavior (e.g., drinking) as a rewarding mechanism.[53,54] This psychological explanation, however, should be regarded as supposition, which warrants additional empirical examination in subsequent research, particularly because psychological variables were not available in the current data set. In addition, a study by Rockafellow and Saules[55] observed a significant relationship between participation in team sports and increased alcohol consumption among physically active college students. The present study, among primarily mid-age participants, was unable to determine whether participation in team sports is as an effect modifier in this relationship because this information was not available in the data set.

Together with observational research examining the intersection of physical activity and alcohol consumption, interventions aiming to reduce excessive alcohol consumption via physical activity promotion have been attempted with mixed success. For example, Kendzor et al.[56] found that encouraging physical activity (e.g., walking, cycling) during a treatment intervention for heavy drinkers, did not result in reduced alcohol consumption. Moreover, a recent systematic review by Thompson et al.[57] indicates that although some studies observed that physical activity markedly reduced alcohol initiation, others did not find that physical activity significantly affected alcohol consumption. The current study's results, reflecting behaviors of adults, indicate that higher levels of fitness are related to increased drinking, particularly moderate alcohol consumption. Thus, when designing interventions for this population, interventions focusing on increasing fitness (through physical activity promotion) might want to concurrently attempt to reduce alcohol consumption.

As expected, the present study finds that heavy alcohol consumption corresponds with a higher prevalence of suggested alcohol dependence (as measured by CAGE). Of interest, however, is an inverse relation between fitness categories and suggested alcohol dependence among men who are heavy drinkers, but not women who are heavy drinkers. That is, in men who are heavy drinkers, as fitness increased, the percentage of those with suggested alcohol dependence decreased. For example, men who drank heavily within the low fitness category had an approximately 1.3 times higher percentage of suggested alcohol dependence than their high fit counterparts (45.7% vs 34.9%, respectively). This finding warrants further investigation, including to determine the potential protective aspects of this relationship for men and why they did not generalize to high fit women. Previous research by Lisha et al.,[58] in a large sample of US adults, found that physical activity was positively related to alcohol consumption but not to severe forms of alcohol use disorders with no differences by sex.

The present study has strengths and limitations that should be considered when interpreting findings. Strengths of the study include the large sample size, the focus on adults attending a preventive medicine clinic with a valid alcohol dependence measure (CAGE), and the use of objective measurements of fitness instead of self-reported physical activity. Although fitness is a quantitative and direct consequence of habitual physical activity, it is also influenced by nonmodifiable factors (e.g., sex, age, genetics).[28,59] In the current study, we present findings for both the behavior (physical activity) and the physiological consequence of this behavior (fitness), which is a strength in the present study. The study's outcome (alcohol consumption), however, as with other epidemiological studies, is based on self-report, which could be subject to underreporting because of social desirability. In addition, inclusion of an explicit reference period (e.g., 12 months or 30 d) for alcohol consumption would improve its measurement.[60] The study is also limited by its focus on a cohort consisting of predominantly White, highly educated participants with access to preventive medical care. As a result, these conclusions might not be applicable to a multi-ethnic and more economically diverse population. Moreover, the present study's focus on apparently healthy adults whose behaviors might not represent individuals with morbid conditions is an additional limitation. Finally, only an association, rather than a temporal and causal relationship, can be established between fitness and alcohol consumption because of the cross-sectional nature of the study.[51]

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