Exercise Reverses the Sedentary Cardiac Phenotype in Obesity: A Systematic Review and Meta-Analysis of Hemodynamic, Structural, and Functional Adaptations

Background and AimSedentary lifestyle and obesity are considered to be significant risk factors that create a pathway for the appearance of the sedentary cardiac phenotype consisting of cardiac atrophy, myocardial stiffening, and altered haemodynamics. Although exercise training has the potential to reverse this detrimental process, the literature data on the magnitude of improvements and the certainty of evidence are inconsistent. This systematic review and meta-analysis aimed to evaluate the effects of exercise interventions on cardiac morphology, systolic/diastolic function, and haemodynamics in sedentary and obesity-prone individuals. MethodIn accordance with the PRISMA guidelines, the study was conducted by searching the PubMed, Web of Science, and Scopus databases from 1990 to 2025 without applying any filters, using Covidence software. As a result of this comprehensive search, 15 randomised controlled trials (RCTs; N=559) comparing exercise training with a control group in sedentary individuals were included in the analysis. Data were pooled using the Standardised Mean Difference (SMD) and a random-effects model. Publication bias and methodological robustness of the results were tested using the Egger regression test, the Trim-and-Fill method, and Leave-One-Out sensitivity analysis. The certainty of the evidence was graded using the GRADE system. ResultsExercise training was associated with a significant reduction in resting HRs and SBPs, which was a strong improvement in the haemodynamic profile. The improvements in SV and LVEF, although on the statistical threshold in the primary analysis, were statistically significant and methodologically stable in the Leave-One-Out sensitivity analysis, which excluded confounding studies. The exercise training was associated with a marked improvement in the E/A ratio and S wave, and the triggering of a physiological athletes heart-like eccentric hypertrophy, defined by improvements in LVMass and LVEDV. The exercise training was associated with diastolic adaptation and mass increase, with HIIT being the most superior method for diastolic adaptation and mass increase, and aerobic exercise being the most effective method for blood pressure reduction. Importantly, the meta-regression analyses revealed two important findings: first, the improvement in blood pressure and diastolic function was independent of weight loss; second, the improvement in structure and function was linearly related to improvements in body composition. ConclusionExercise acts as a cardiac polypill reversing the sedentary phenotype by improving hemodynamics and diastolic function independently of weight loss, while linking structural remodeling to BMI optimization; our data prioritize HIIT for structural/diastolic gains and Aerobic training for blood pressure control.