Using a 2 x 2 factorial design with continuous effect endpoint ( Maximal Oxygen Uptake ( VO2peak ) ) , 380 patients with non-small cell lung cancer ( NSCLC ) stage I-IIIa referred for surgical resection will be randomly assigned to one of four groups : ( 1 ) preoperative and early postoperative rehabilitation ( starting two weeks after surgery ) ; ( 2 ) preoperative and late postoperative rehabilitation ( starting six weeks after surgery ) ; ( 3 ) early postoperative rehabilitation alone ; ( 4 ) today 's standard care which is postoperative rehabilitation initiated six weeks after surgery .