BACKGROUND : Evidence emerges that cardiorespiratory fitness (CRF) might be implicated in the development of heart failure (HF). This meta-analysis aimed to quantify the association between CRF exposed at baseline and HF risk with dose-response analysis and to assess whether CRF changes over time are correlated with alterations in HF risk. RESULTS : Cohort studies that assessed the association between CRF and risk of HF in subjects without baseline HF were included. Study-specific multivariate-adjusted relative risks (RRs) with 95% confidence intervals (CIs) were pooled using a random-effects model. Ten studies from 8 articles were included, enrolling 8987 incident HF cases from 154,598 participants. The RR of HF per 1-metabolic equivalent (MET) higher CRF at baseline was 0.82 (95% CI 0.80-0.84) in the overall population. The RRs were similar in men (0.82, 95% CI 0.80-0.85) and women (0.81, 95% CI 0.78-0.84), and remained minorly changed in patients with existing diabetes, hypertension, or cardiovascular disease at entry. No evidence of a nonlinear relationship between CRF at baseline and risk of HF was observed (Pnonlinearity = .18). The RR of HF per 1-MET increase in CRF over time was 0.79 (95% CI 0.67-0.93), and the measurement of CRF provided incremental value to the prediction of HF beyond conventional models. CONCLUSIONS : High or increased CRF resulted in reduced risk of HF in a dose-dependent manner, supporting the necessity to increase CRF to prevent HF in clinical practice.