Background Many patients with lung cancer are deconditioned with poor physical fitness. Lung resection reduces physical fitness further, impairing the patient's ability to function in daily life.

Methods We conducted a single-blind randomised controlled trial of high-intensity endurance and strength training (60 min, three times a week, 20 weeks), starting 5–7 weeks after surgery. The control group received standard postoperative care. The primary outcome was the change in peak oxygen uptake measured directly during walking until exhaustion. Other outcomes included changes in pulmonary function, muscular strength by one-repetition maximum (1RM), total muscle mass measured by dual energy X-ray absorptiometry, daily physical functioning and quality of life (QoL).

Results The intention-to-treat analysis of the 61 randomised patients showed that the exercise group had a greater increase in peak oxygen uptake (3.4 mL/kg/min between-group difference, p=0.002), carbon monoxide transfer factor (Tlco) (5.2% predicted, p=0.007), 1RM leg press (29.5 kg, p<0.001), chair stand (2.1 times p<0.001), stair run (4.3 steps, p=0.002) and total muscle mass (1.36 kg, p=0.012) compared with the controls. The mean±SD QoL (SF-36) physical component summary score was 51.8±5.5 and 43.3±11.3 (p=0.006), and the mental component summary score was 55.5±5.3 and 46.6±14.0 (p=0.015) in the exercise and control groups, respectively.

Conclusions In patients recently operated for lung cancer, high-intensity endurance and strength training was well tolerated and induced clinically significant improvements in peak oxygen uptake, Tlco, muscular strength, total muscle mass, functional fitness and QoL. This study may provide a basis for exercise therapy after lung cancer surgery.

Trial registration number NCT01748981.