As physical activity levels continue to decline among young adults, identifying strategies to promote movement has become a growing public health priority. One proposed approach is to emphasize the cognitive benefits of physical fitness, such as improved learning and memory. However, the evidence for a direct relationship between physical fitness and learning efficiency in a young, healthy population, remains limited. This study aimed to investigate whether individual differences in physical fitness predict immediate learning performance in young adults. A total of 77 participants completed a memory task based on educational videos, followed by a physical fitness assessment using both self-report (International Fitness Scale, IFIS) and objective data from smartwatches (VO₂max estimates). Results showed a significant correlation between IFIS scores and VO₂max, supporting the validity of the self-report measure. However, neither the overall IFIS score nor its specific subcomponents significantly predicted performance on the learning task. These findings suggest that while subjective fitness reflects physiological capacity to some extent, it does not reliably predict learning efficiency in this context. The results raise important questions about when and how physical fitness may influence cognition and highlight the need for experimental designs that consider timing, task sensitivity, and how fitness in measured.