The proliferation of wearable fitness tracking technologies has generated unprecedented access to personal health metrics, yet simultaneously created significant challenges related to information processing and cognitive load. This systematic review and theoretical analysis examine the phenomenon of data overload in fitness tracking, its multifaceted impacts on user experience, and evidence-based approaches for mitigating these challenges. Through meta-analysis of 47 peer-reviewed studies and qualitative assessment of user-generated content across digital platforms, I identified four primary dimensions of fitness tracking data overload: cognitive-attentional burden, contextual relevance deficits, visualization inadequacies, and ecosystem fragmentation. I propose a novel Adaptive Information Architecture Framework (AIAF) that conceptualizes data presentation as a dynamic system responsive to user expertise, contextual needs, and cognitive capacity. My findings reveal that effective mitigation of data overload requires transcending simplistic data reduction approaches in favor of intelligent information architecture that preserves data richness while optimizing cognitive accessibility. This work contributes to both theoretical understanding of human-information interaction in health contexts and practical implementation of more effective fitness tracking interfaces. I conclude with a research agenda addressing methodological gaps in longitudinal engagement patterns, personalization algorithms, and psychophysiological responses to different information presentation modalities. Keywords: Wearable Technology, Fitness Tracking, Cognitive Load Theory, Information Architecture, Human-Computer Interaction, Digital Health, User Experience, Data Visualization, Behavioral Informatics