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