Objective: To evaluate the influence of an interval training program for the upper limbs on cardiorespiratory fitness and walking ability in elderly patients after total hip joint arthroplasty. Design: A randomized controlled trial. After surgery, control and training groups started general rehabilitation. Training group combined it with an arm-interval exercise program (3 sessions of 30 minutes per week, for 6 weeks). Subjects: Patients were assigned randomly to control (n = 7) and training groups (n = 7). Methods: Incremental exercise tests were carried out until exhaustion on an arm crank ergometer 1 month before and 2 months after surgery. A 6-minute walk test was also performed 2 months after surgery. Results: _ V O 2 peak increased significantly in the training group (p = 0.0424) and did not change in the control group. The difference in _ VO 2 peak change between the groups was significant (p = 0.0362, 19.2% in the training group and À3.5% in the control group). In the walking test the training group covered a significantly longer distance than did the control group (p = 0.0055, 396.4 metres and 268.1 metres, respectively). Conclusion: These results stress the importance of physical training in a rehabilitation program after total hip joint arthroplasty and this should be considered for improving the current practices in rehabilitation.