The observational UK Biobank analysis of 17,088 adults (mean age 57, 56% female) published in the British Journal of Sports Medicine reveals that substantial cardiovascular risk reduction (>30%) requires 560-610 minutes of moderate-to-vigorous activity weekly—nearly four times current guidelines. This aligns with patterns seen in prior large cohorts but highlights personalization by fitness level, with lower-VO2-max individuals needing 30-50 extra minutes for equivalent benefit. Unlike RCTs, this study cannot establish causation and carries healthy-user bias plus estimated rather than directly measured fitness; no conflicts were declared by Macao Polytechnic researchers. It builds on a 2019 meta-analysis in the European Heart Journal (n>800,000) showing dose-response curves plateauing only at higher volumes, and a 2022 JAMA Cardiology paper on NHANES data linking low cardiorespiratory fitness to 2-3x higher event rates. Original coverage underplays how deconditioning creates a steeper barrier and overlooks adherence challenges in real-world settings, where sedentary time—unmeasured here—often offsets gains. Public health implications are profound: universal minimums remain valid but stratified targets could prevent far more events if paired with fitness assessments.