ECPN Student Poster Contestant: A Longitudinal Investigation of the Association between Alcohol Use and Physical Activity in College Students

Introduction: To date, researchers have exclusively studied the association between alcohol use and physical activity (PA) among college students using cross-sectional designs. Because of this constraint in the literature, there is limited evidence regarding the extent that one behavior influences the other. To address this knowledge gap, we conducted a longitudinal investigation to explore the reciprocal association between exercise and alcohol consumption behaviors over time.

Method: As part of a broader study on student health behaviors, we sampled 396 college students (M_age = 20.97; 62% female) at three time points: baseline, 3-month follow-up, and 6-month follow-up. At each time point, participants indicated their typical levels of vigorous and moderate PA (i.e., days per week and average minutes per bout), as well as their alcohol use over the past month (i.e., frequency of alcohol consumption). To disentangle between- and within-person variance across time points while controlling for autoregressive effects, we used a random intercept cross-lagged panel model to investigate the association between PA and alcohol use over time. Separate models were conducted for vigorous and moderate PA.

Results: Intraclass correlation coefficients indicated that 38% of the variance in alcohol use, 47% of the variance in vigorous PA, and 77% of the variance in moderate PA were due to within-person variance over time – meaning that multilevel analyses were prudent. At the within-person level, alcohol use at baseline did not predict vigorous PA at the subsequent 3-month follow-up (β = .11, p = .059), but alcohol use at the 3-month follow-up positively predicted vigorous PA at the 6-month follow-up (β = .17, p = .009). In contrast, vigorous PA was not a significant cross-lagged predictor of alcohol use. Results further showed that, at the between-person level, alcohol use was not significantly associated with vigorous physical activity. A second model to test the association between alcohol use and moderate PA indicated that there were no significant cross-lagged associations in either direction, nor a significant association at the between-person level.

Conclusion: The current study expands the knowledge base regarding alcohol use and PA in college students by investigating the extent that each behavior ‘drives’ the association, and by distinguishing variance explained at the between-person level from the within-person level. Alcohol use positively predicted vigorous PA, but only at the within-person level. This indicates that a person’s deviation from his or her own vigorous PA is predicted by his or her own deviation in alcohol use at an earlier assessment, but that there was no association between stable between-person differences in these behaviors.