Exercise intervention
The physical exercise intervention comprised 6 months of twice a week one hour supervised training sessions, consisting of both aerobic training and strength exercises, and twice a week one hour Nordic or power walking sessions. Supervised sessions were delivered by a physiotherapist, close to the patient’s home address. Intensity of the aerobic training was based on individual physical fitness levels, which were measured at baseline with a cardiopulmonary exercise test (CPET); intensity for strength exercises was based on repeated 20-repetition maximum (20-RM) and 15-RM muscle strength tests, performed by the physiotherapist. Intensity progressed throughout the supervised program (