Exploring the Role of Biofeedback in Physiological Monitoring of Alcohol and Caffeine Consumption in Collegiate Softball Athletes

Alcohol and caffeine, when consumed in excessive amounts, may negatively impact performance, health, and well-being. Nevertheless, college athletes have been shown to commonly consume these substances at a high level despite numerous interventions in place to moderate intake. The goal of this pilot project was to explore the role of biofeedback in monitoring and influencing alcohol and caffeine consumption among collegiate athletes. Twelve female NCAA Division I collegiate softball athletes (age: 19.1 ± 1.3; race: Caucasian/Non-Hispanic n=11,) wore a WHOOP® strap non-stop for 60 days to measure resting heart rate (RHR), heart rate variability (HRV), recovery (calculated from HRV, RHR, and hours of sleep), sleep, and energy (kcals) expended. Subjects also completed a brief daily survey regarding alcohol and caffeine intake during the previous 24 hours. At the end of the 60-day period, subjects participated in a semi-structured interview regarding their perception of the impact of wearing the WHOOP® strap on health-related behaviors. Overall, subjects consumed alcohol on 19.2±6.0% of days, at a rate of 1.0±0.7 servings of alcohol per day (range: 0 to 14 servings). Caffeine intake was 100.3±75.9 mg of caffeine per day. Alcohol intake was negatively associated with next-day and weekly recovery % (r=-0.304, p<0.001 and r=-0.576, p=0.02 respectively), sleep % (r=-0.286, p<0.001 and r= -0.434, p= 0.04) respectively), HRV (r=-0.251, p=<0.001 and r= -0.530, p= 0.029 respectively), and kcals expended (r=-0.213, p<0.001 and r= -0.528, p= 0.029 respectively), and was positively associated with next-day RHR (r=0.333, p<0.001). Caffeine intake was positively associated with weekly RHR (r= 0.653, p= 0.010) and negatively associated with next-day and weekly HRV (r=-0.079, p=0.034 and r= -0.500, p= 0.034 respectively), but not with any other measure. Eight of the twelve subjects perceived that the WHOOP® strap influenced their behavior in some way (sleep: n=6, caffeine: n=3, alcohol: n=2). In conclusion, alcohol and caffeine intake influenced multiple WHOOP® strap-derived physiological measures in a small cohort of collegiate softball players. This method of biofeedback shows promise for monitoring alcohol and caffeine consumption and potentially modifying related behaviors in athletes.