A significant intervention effect was observed for vigorous-intensity exercise ( effect size : Cohen 's d , 0.46 ; 95 % confidence interval [ CI ] , 0.09-0 .82 ; P = .010 ) but not for combined moderate and vigorous exercise levels ( effect size : d , 0.08 ; 95 % CI , -0.28 to 0.45 ; P = .48 ) .