This study offers an in-depth examination of how various social, personal, physiological, environmental, and behavioral factors are associated with both sleep and active heart rate dynamics among college students. Utilizing data collected from 487 participants over a span of 637 days via wearable technology, this research aims to unravel the intricate relationships that influence heart rate variations. Through the application of latent growth-curve modeling, we meticulously analyzed the trajectory of heart rate changes and their associations with a broad spectrum of influencing factors. This methodological approach allowed for a nuanced understanding of the dynamic interplay between heart rate and its determinants over time. The analysis revealed a consistent increase in both sleep and active heart rates across the study period, accompanied by stable standard deviations. Peer influence significantly impacted sleep and active heart rates, especially at rest. Gender and race/ethnicity were associated with heart rate dynamics, as were conscientiousness and depression levels. Environmental factors, including days of the week, academic periods, and weather conditions, exhibited significant effects. Behavioral factors, such as physical activity and daily class attendance, played a substantial role in heart rate patterns. Our findings underscore the complex interplay of factors influencing heart rate dynamics in young adults. Tailored interventions should consider these multifaceted influences to promote optimal cardiovascular well-being.