Aerobic Exercise Response Variation and Cardiorespiratory Fitness in Adults with Coronary Heart Disease: An SDir...

Given that true exercise response variation on cardiorespiratory fitness in adults with coronary heart disease (CHD) is not known, this study addressed this gap.

Randomized controlled trials (RCTs) comparing continuous aerobic exercise (CAE) to controls in adults ≥18 years of age with CHD were included. The primary outcome was exercise-associated inter-individual response differences (IIRDs) in cardiorespiratory fitness (VO_2peak in ml·kg^-1·min^-1). Using the inverse variance heterogeneity (IVhet) model, a standard deviation of individual response difference (SD_ir) meta-analysis was conducted. Ninety-five percent confidence intervals (CIs) and prediction intervals (PIs) were calculated.

Twenty-eight RCTs representing 1383 participants (725 CAE, 658 control) were included. Statistically significant and clinically important improvements (≥1.0 mL·kg^-1·min^-1) were observed for VO_2peak as a result of CAE (X¯, 3.6, 95% CI, 2.8 to 4.4 mL·kg^-1·min^-1, p < 0.001), but no statistically significant or clinically important IIRD based on the SD_ir were found (X¯, 0.9, 95% CI, -1.5 to 2.0 mL·kg^-1·min^-1; 95% PI, -2.4 to 2.7). Based on GRADE, the strength of evidence was of low certainty.

There is low certainty evidence that CAE results in statistically significant and clinically important improvements in VO_2peak in adults with CHD, but no exercise-associated IIRD was observed once properly accounted for.