Sustained improvements in cardiovascular fitness and body composition after lifestyle interventions are challenging. The present study investigated whether changes in cardiovascular fitness and body composition were maintained for up to 1 year after similar exercise-induced (T) or diet-induced weight loss (D) or exercise without weight loss (T-iD) in overweight sedentary men. Six and 12 months after the interventions, we measured cardiovascular fitness and body composition. Cardiovascular fitness was higher at both 6- (3.2±1.5 ml O2/kg/min, P=0.053) and 12-month follow-up (3.9±1.4 ml O2/kg/min, P=0.049) compared with pre-intervention in T. Fat mass (-3.0±1.2 kg, P=0.04) and abdominal fat (-3.6±1.5%, P=0.04) were lower within T at 12-month follow-up compared with pre-intervention. This did not occur in D (P>0.13) or T-iD (P>0.14), although body weight was lower in D (-2.5±2.2 kg, P=0.09). This study showed that fitness and fatness were not returned to pre-intervention levels 1 year after a 3-month exercise-induced weight-loss intervention.