| Abstract: |
Exercise as medicine has emerged as a cornerstone of non-pharmacological chronic disease management. Global physical activity guidelines universally prescribe moderate-to-vigorous physical activity (MVPA) as the primary intensity threshold for health benefit. However, a paradox exists: the clinical populations most in need of exercise medicine consistently fail to meet these prescriptions, thereby nullifying the therapeutic intent. This paper investigates how rigid MVPA prescription frameworks inadvertently reduce the clinical reach of exercise as medicine by creating adherence barriers that are both physiological and behavioural in nature. The objectives are to examine population-level adherence failure in clinical cohorts and to evaluate whether intensity-flexible prescriptions improve clinical outcomes. A narrative-analytical methodology was adopted, drawing on published meta-analyses, longitudinal cohort studies, and systematic reviews (2018–2025). The central hypothesis is that reconceptualising exercise prescriptions to include light-intensity physical activity (LPA) alongside MVPA will improve real-world adherence without proportionally compromising clinical efficacy. Evidence from large-scale accelerometry and epidemiological studies confirms this hypothesis, revealing that LPA at adequate volumes produces clinically significant mortality risk reductions. Findings challenge the primacy of MVPA and support a shift toward individualised, intensity-flexible exercise medicine frameworks. |
