Mitochondrial Proteome of Cardiomyocytes: Significance of proteins and enzymes for bioenergetics, cellular homeostasis, and signal transduction in heart cells under endurance load, oxidative stress, and adaptive remodeling — with translational links to triathlon, special forces, and longevity

This preprint presents a synthetic hypothesis-driven framework for interpreting the mitochondrial proteome of cardiomyocytes, focusing on proteins that govern bioenergetics, mitochondrial network dynamics, and stress responses. A central theme is the coupling between mitophagy and mitochondrial biogenesis as a quality-control mechanism under high hemodynamic and oxidative load. Key signaling axes (including AMPK–PGC-1α, SIRT3, and NRF1/2) are discussed in relation to cardiac metabolic adaptation and fuel switching during prolonged endurance effort. We propose that distinct expression patterns across respiratory chain complexes, β-oxidation enzymes, metabolite transporters, and Ca²⁺-handling regulators may differentiate physiological adaptation (e.g., triathlon training) from maladaptive responses under extreme stress. Translational links are outlined between ‘mitochondrial resilience’ and longevity, arrhythmia risk, heart failure trajectories, and metabolism-dependent cancer biology. The manuscript integrates literature evidence with practical observations and uses AI-assisted mapping to connect proteins into functional modules and pathway dependencies. Potential biomarkers—both proteomic and physiological—are highlighted for tracking load, recovery, and early dysfunction signals, including oxidative stress markers and mtDNA integrity proxies. A time-structured evaluation approach is proposed (baseline vs. training cycles), incorporating wearable-derived metrics and hemodynamic parameters. Overall, the conclusions are conceptual and designed to guide future experimental validation in endurance athletes and populations exposed to extreme operational demands.