Sleep, Caffeine, And Exercise: The Relationship Between Behavior And Cognition

Sleep hygiene, caffeine consumption, and exercise behavior vary widely among young adults. Modest variations may affect learning and capability. A greater understanding of the interaction between these behaviors and cognition is warranted. PURPOSE: To investigate the relationship between daily caffeine intake, sleep duration, and participation in aerobic exercise (AE) and resistance training (RT) on cognition in young adults. METHODS: We screened recreationally active men (n = 13) and women (n = 16). All subjects were tested 3 times; each session was 3 days apart. Subjects wore sleep tracking devices that exported duration of sleep the night before testing. During each session, they documented recent caffeine consumption and participation in AE and RT. These served as independent variables. Subjects then completed the Human Benchmark test (HBT) to appraise reaction time, and the Psychology Today (PT) mental speed test, measuring efficiency of rapid information processing. Linear regressions evaluated the relationships between behavioral variables and test scores. RESULTS: Subjects were 22.6 ± 7.8 years of age, 62% participated in AE, 69% participated in RT, and caffeine was consumed by 59%. Across all three dates, mean sleep duration was 423.4 ± 144.7 min, HBT score was 308.6 ± 89.6, and mean PT test percentage was 70.6 ± 17.2%. There were no significant associations during session 1. During session 2, participation in AE predicted an improvement of 50.0 points on the HBT (R2 = 0.203; p = 0.036; 95% CI of β: 3.733, 96.284). During session 3, subjects reported less sleep (384.0 ± 121.7 min); the difference was not significant (p = 0.098). Sleep had an inverse association with HBT score (R2 = 0.306; p = 0.009; 95% CI of β: -0.324, -0.052). Additionally, AE had an inverse association with the PT test percentage (R2 = 0.471; p < 0.001; 95% CI of β: -38.191, -11.919). There were no associations with resistance training or caffeine consumption on either cognitive test. CONCLUSION: Sleep duration and aerobic exercise affect psychological performance. In this analysis, resistance training and caffeine consumption did not. The small sample delimits thorough evaluation; however, as educational environments continue to change, furthering our understanding of these interactions can guide behaviors to favor learning.